Category Archives: Chemistry

Thalidomide

In class, we recently discussed the thalidomide incident and how it represented a pivotal shift in the way drugs were developed—particularly in providing an insight into the way drugs taken by a pregnant mother affect her baby. I was reminded of this while reading the news yesterday, as I came across this article discussing a case that could lead to the criminalization of alcohol consumption during pregnancy. (Gander, 2014)

Case: A six-year old girl suffered brain damage because of her mother’s alcohol consumption while carrying her—and it is now being argued that she is the victim of a crime / criminal offense committed by her mother.

This article deeply intrigued me, as I thought about all the implications that a law like this, if passed, could have. As we have (in our Medicines & Drugs unit) studied the effects that alcohol has on the body, I decided to investigate the chemistry of alcohol as it affects her mother and baby to answer the following question: to what extent does alcohol consumption by a mother negatively impact her baby?

I found that, once consumed, most substances are broken down in an intermediate step by enzymes (biological catalysts) to “metabolites”: other compounds that can be easily processed by the body. However, the alcohol we consume (ethanol– CH3CH2OH), is broken down by the body to the toxic and carcinogenic Ethanal (also called ‘Acetaldehyde’: CH3CHO). (Alcohol Metabolism: An Update, 2007)

The breakdown of Ethanol

Figure 1. The breakdown of Ethanol by the body.
(Alcohol Metabolism: An Update, 2007)

Note: ADH (Alcohol Degenerase) and ALDH (Aldehyde Degenerase) are the enzymes that catalyze the reactions.

As we can see from the above equation, in normal (non-pregnant) individuals the Ethanal is usually short-lived as it serves as an intermediate to when it is further broken down to Ethanoic Acid (also called ‘EthylAcetate’: CH3COOH), and then to carbon dioxide and water, after which it is eliminated from the body. (Alcohol Metabolism: An Update, 2007)

Ethanal itself is an aldehyde, and contains 2 carbons, a methyl group and its characteristic aldehyde functional group (C=O double bond).

Structure of Ethanal

Figure 2. Structure of Ethanal
(Environmental Chemistry: Lecture 21, n.d)

In pregnant women, this compound does pose a risk for their babies. A meta-analysis of 14 studies found that while 43% of pregnant alcoholics had high levels of acetaldehyde in their blood, 34% of them gave birth to a baby with ABRD (Alcohol Related Birth Defect). The researchers concluded that acetaldehyde “may play a major role in the cause of ARBD”. (Hard, Einarson, & Koren, 2001)

The precise mechanism as to how acetaldehyde impacts a fetus is not yet known, but alcohol in general has also been found to increase risk of foetal damage, and the risk of miscarriage. (Abuse and Mental Health Services Administration, n.d;  Bailey & Sokol, 2011) Other investigations have linked alcohol to damaging the DNA of a growing/ developing baby in the womb (however, these investigations have so far only been conducted on lab mice). (Medical Research Council, 2011) Already, a 50% increase has been seen in FAS cases (Fetal Alcohol Syndrome) in the past three years, and the Department of Health estimates that 1/100 babies are born with alcohol-related disorders. (Gander, 2014)

The adoptive mother of the six-year old has seen first-hand the consequences that alcohol consumption can have on children, and strongly believes that the legal system should step in and enforce some laws to prevent against further cases of FAS. “You can’t make it a criminal offense if you are still legally saying this a safe amount to drink, or you can drink. It needs to be clear from the start that you can’t [drink]”. (Gander, 2014)

Her argument is also supported by Dr. Raja Mukherjee, a consultant psychiatrist, who asserts that even minimal consumption by a woman during pregnancy puts her baby at risk for FAS, “If you want to guarantee safety and you want to guarantee no risk then no alcohol is the best way forward”. (Gander, 2014)

The implications of a law criminalizing the consumption of alcohol while pregnant will certainly serve to reduce the high numbers of babies suffering from ABRDs such as FAS. Babies suffering from FAS are usually hyperactive and delayed in their development– if exposed to high levels of alcohol while in the womb, they can display withdrawal symptoms such as extreme irritability, shaking, and diarrhea. Additionally, school aged children with FAS often experience learning and behavioral disabilities, and for this reason find themselves falling behind in school. They also are high at risk for having trouble with the law, developing mental health problems and themselves abusing alcohol and/ or drugs. (Canadian Paediatric Society, 2002) Considering this, as well as the previously conducted research demonstrating other harmful effects of alcohol consumption during pregnancy, it is apparent that alcohol is to a large extent extremely damaging to developing babies. A law criminalizing this act may not be the worst idea.

References

(2007). Alcohol Metabolism: An Update. Alcohol Alert, 72. Retrieved February 23, 2014, from http://pubs.niaaa.nih.gov/publications/AA72/AA72.htm

Bailey, B. A., & Sokol, R. J. (2011). Prenatal Alcohol Exposure and Miscarriage, Stillbirth, Preterm Delivery, and Sudden Infant Death Syndrome . Alcohol Research & Health, 34(1), 86-91. Retrieved February 23, 2014, from the NIAAA Publications database.

Paediatric Society. (2002). Fetal alcohol syndrome: What you should know about drinking during pregnancy. Paediatrics & Child Health , 7(3), 177-178. Retrieved February 24, 2014, from the PMC database.

Environmental Chemistry: Lecture 21. (n.d.). NAU Courses. Retrieved February 23, 2014, from http://jan.ucc.nau.edu/~doetqp-p/courses/env440/env440_2/lectures/lec21/lec21.html

Gander, K. (2014, April 23). Drinking alcohol while pregnant could become a crime after landmark test case . The Independent. Retrieved February 23, 2014, from http://www.independent.co.uk/life-style/health-and-families/health-news/drinking-alcohol-while-pregnant-could-become-a-crime-after-landmark-test-case-9147417.html

Hard, M. L., Einarson, T. R., & Koren, G. (2001). The Role of Acetaldehyde in Pregnancy Outcome After Prenatal Alcohol Exposure. Therapeutic drug monitoring, 23(4), 427-434. Retrieved February 23, 2014, from the PubMed database.

Research Council. (2011, July 6). Excess alcohol could damage our DNA. Medical Research Council News. Retrieved February 23, 2014, from http://www.mrc.ac.uk/Newspublications/News/MRC008040

Abuse and Mental Health Services Administration. (n.d.). Effects of Alcohol on the Developing Embryo and Fetus. FASD Center for Excellence. Retrieved February 23, 2014, from http://fasdcenter.samhsa.gov/educationTraining/courses/CapCurriculum/competency1/effects1.aspx

Can breathing kill you?

The October break gave me a lot of time to unwind, and was a nice break from the stressful and always dreaded “IB Year 2 Semester 1”. One of the ways I decided to spend my downtime was by blogging on a social media site called Tumblr, and it was then that I came across this post:

Post originally by http://harrystyies.tumblr.com/

As we were studying Oxidation and Reduction in class, I had to investigate the idea further.

A quick Google search on the statement led me to a thread on The Student Room (UK) with others also discussing their fears: was breathing ultimately killing them?

A Clarifying Question by Ruthless Dutchman

A Bold Statement by Broken Social Gene

Some users showed their support and offered scientific explanations-

Explanation by Toquin, A Respected Member

It made sense… I had learned from Biology class that one of the reactants required for the process of cellular respiration is Oxygen which comes from the air that we breathe. Further research led me to a report linking Oxidative Stress (essentially a deficiency of anti-oxidants) to a string of diseases including Diabetes and Arteriosclerosis (Vendemiale et al., 1999). I realized then that this was not a debate to be taken lightly, and decided to investigate the following question for my blog post: to what extent does Oxygen harm the human body?

I turned to the experts for some insight.

It turns out, Oxidation is a natural occurrence when there is exposure to air. Cut an apple and leave it out, it will undergo Oxidation and slowly change color (to brown). Leave equipment made from Iron out unprotected, and it will rust. Breathe, and your cells will decay.

Oxygen in our body reacts with our cells, and as a result, these cells undergo oxidation. As oxidation is the loss of electrons, the affected cell is chemically altered and ultimately dies. It is then replaced by fresh, new cells. According to Jeffrey Blumberg, a professor of nutrition at Tufts University in Boston, this is nothing to worry about. Blumberg dismisses any fears about oxidation by saying that it is a “natural process” that occurs “during normal cellular functions” (Davis, n.d).

However, what we do have to worry about are those cells that are unintentionally damaged in the process- Blumberg asserts that although the metabolism of oxygen in the body is “efficient”, 1% – 2% of cells will suffer this damage in the process (Davis, n.d). This damage occurs by the breaking of covalent bonds between their molecules (SucceedMonavie, 2010). As two molecules split apart, the shared electron is released and both molecules become unstable and highly reactive as a result. These unstable and highly reactive molecules are known as ‘free radicals’, and are a type of Reactive Oxygen Species (Evans & Halliwell, 1999).

Molecule before Oxidation
Molecule before Oxidation – (SucceedMonavie, 2010)
Molecule breaks apart, releasing an electron
Molecule breaks apart, releasing an electron – (SucceedMonavie, 2010)
Molecules turn into unstable 'Free Radicals'
Molecules turn into unstable ‘Free Radicals’ – (SucceedMonavie, 2010)

Because of their unstable nature, ‘free radicals’ will attack healthy cells in an attempt to act as as an oxidizing agent to gain back an electron and achieve stability (SucceedMonavie, 2010). According to Blumberg, “these molecules will rob any molecule to quench that need [for an electron]”, and this makes the ‘free radicals’ potentially very dangerous (Davis, n.d). When attacked molecules are oxidized by a free-radical, the attacked molecules turn into free radicals themselves (SucceedMonavie, 2010). As 1 free-radical breaks apart a bond between 2 healthy cells to undergo reduction, 1 free-radical (if not stopped) is later responsible for the production of 2 radicals. This statistically works similar to bacteria growth, and results in a chain-reaction that produces a rapid and exponential increase in the number of ‘free radicals’ present in our body. Oxidative stress, defined as “a disturbance in the balance between the production of reactive oxygen species (free radicals) and anti-oxidant defenses” can be attributed to this chain reaction (Betteridge, 2000). It has been linked to various heart diseases and cancers, as well as to Alzheimer’s and Parkinson’s disease (Davis, n.d).

'Free Radicals' attack nearby healthy cells
‘Free Radicals’ attack nearby healthy cells   –   (SucceedMonavie, 2010)
1 'Free Radical' oxidizes 2 healthy cells
1 ‘Free Radical’ oxidizes 2 healthy cells – (SucceedMonavie, 2010)

Additionally, as the ‘free radicals’ attack healthy cells around them, they may not kill the healthy cells. This can potentially lead to devastating consequences for the body. According to Blumberg, “if free radicals simply killed a cell, it wouldn’t be so bad… the body could just regenerate another one”. He instead suggests that the problem lies with damage to the cell, as this damages the DNA which leads to the mutation of the affected cell, as well as abnormal growth and reproduction of that cell- “the seed of disease” (Davis, n.d).

So oxygen is harmful to the human body? Why don’t we just stop breathing?

I realized that the initial post had been right, to a certain extent. Although Oxygen does have the potential to do damage to our bodies, it is also vital to our survival- and it certainly does not “take 80 years to kill us”. We must also remember that only 1% – 2% of metabolized Oxygen actually turns into a ‘free radical’ (Davis, n.d). Valko et al. (2007) look to Reactive Oxygen Species as being “two faced”- though these can damage cell structures, proteins, and DNA, they can simultaneously strengthen the immune system. As this strengthened immune system can then combat a host of illnesses including Oxidative Stress, the actions of Reactive Oxygen Species “re-establish” and “maintain redox balance” or “redox homeostasis” (Valko et al., 2007). Interestingly enough, there are animals out there who do not need any oxygen whatsoever to survive (Danovaro et al., 2010). For us however, oxygen is required for cell respiration to occur- if you don’t breathe, you die.

So how can we take active measures to slow down the process of Oxidation and prevent the onset of Oxidative Stress?

The initial post on Tumblr was right to a certain extent; anti-oxidants do serve this purpose. Anti-oxidants are able to stop the dangerous chain reaction by donating one of their electrons to the unstable ‘free radical’, therefore stabilizing it. They are not oxidized in the process (this is one of their properties), so all potential harm is eliminated from the body (SucceedMonavie, 2010). It is for this reason that Oxidative Stress occurs only when there is an imbalance in the amount of ‘free radicals’ and levels of anti-oxidants present in the body; if the body is lacking in anti-oxidants or abundant in ‘free radicals’, then there will not be enough anti-oxidant to stop the chain reaction from occurring. Increasing intake of anti-oxidants will prevent the sickness from developing (Davis, n.d). Some common foods high in anti-oxidants are tomatoes, carrots, tea, and citrus fruits. Fun fact relating to China- Chinese oolong tea in particular, is 40 times richer in anti-oxidants than regular green tea (Rutherford, 2011). Blumberg urges, “Sure, you can live your whole life without getting epicatechin 3-gallate, a flavonoid found in huge quantities in green tea, but if having it in your diet promotes better health, why not try it?” (Davis, n.d)

Anti-Oxidant on the scene
Anti-Oxidant on the scene   –  (SucceedMonavie, 2010)
Anti-Oxidant donates an electron
Anti-Oxidant donates an electron to the ‘Free Radical’ to stabilize it (SucceedMonavie, 2010)
Anti-Oxidant remains neutral, and 'Free Radical' is reduced / stabilized
Anti-Oxidant remains neutral, and ‘Free Radical’ is reduced / stabilized –  (SucceedMonavie, 2010)

Decreasing the risk of developing ‘free radicals’ in the body can also be a preventative measure. Although my blog post focused specifically on the action of Reactive Oxygen Species, there are other types of free radicals as well. One of these is the Reactive Nitrogen Species, taken into the body by breathing in Nitric Oxide (Valko et al., 2007). This is present in polluted air, something we are very much exposed to as residents of Shanghai. Blumberg asserts that the “toxins” present in the air of a city environment cause an “oxidative burden” on the body which is, with modernization and increased industry and technology, much higher than ever before. He also labels cigarette smoke as having “active free radical generators”, and recommends quitting smoking to “preserve health” (Davis, n.d). Minimizing exposure to pollution and second-hand smoke are also important steps that can taken to do this.

Other factors that can contribute to Oxidative Stress if exposed to in excess, are X-Rays, sunlight, strenuous exercise, and alcohol (Parnes, n.d). Although X-Rays are unavoidable for medical reasons, limiting consumption of alcohol and increasing consumption of anti-oxidants when participating in strenuous exercise or gaining excessive exposure to sunlight can reduce risk of developing Oxidative Stress.

So what? Who cares? (Implications)

Living in China, a country with huge amounts of pollution, increases our risk of developing Oxidative Stress. Additionally, as the sickness has been linked to a host of diseases, preventative measure should be taken in order to minimize the risk of developing those illnesses. Awareness of risk factors of the sickness can help us take these preventative measures.

References

DJ, B. (2000). What is Oxidative Stress?. Metabolism: Clinical And Experimental , 49, 3-8. Retrieved October 7, 2013, from the PubMed database.

Danavaro, R., Dell’Anno, A., Pusceddu, A., Gambi, C., Heiner, I., & Kristensen, R. (2010). The First Metazoa Living in Permanently Anoxic Conditions. BMC Biology, 8(30). Retrieved October 9, 2013, from http://www.biomedcentral.com/1741-7007/8/30/abstract

Davis, J. (n.d.). How Antioxidants Work: Preventing Free Radical Damage and Oxidation. WebMD. Retrieved October 7, 2013, from http://www.webmd.com/food-recipes/features/how-antioxidants-work1

Evans, F., & Halliwell, B. (1999). Free Radicals and Hearing: Cause, Consequence, and Criteria. Annals of the New York Academy of Sciences, 884, 19-40. Retrieved October 7, 2013, from the PubMed database.

Parnes, R. (n.d.). What is an Antioxidant?. Discovery Health. Retrieved October 7, 2013, from http://health.howstuffworks.com/wellness/food-nutrition/facts/antioxidant1.htm

Rutherford, D. (n.d.). Antioxidants and oxidative stress. NetDoctor. Retrieved October 6, 2013, from http://www.netdoctor.co.uk/focus/nutrition/facts/oxidative_stress/oxidativestress.htm

SuceedMonavie. (2010, January 2). How antioxidants work. Youtube. Retrieved October 7, 2013, from https://www.youtube.com/watch?v=lG3OOXIXvxw

Suraru. (n.d.). Tumblr. Retrieved October 5, 2013, from http://suraru.tumblr.com/post/58158026731/gundamdick-thepioden-hair-old-styles

Valko, M., Leibfritz, D., Moncol, J., Cronin, M., Mazur, M., & Telser, J. (2007). Free Radicals and Antioxidants In Normal Physiological Functions and Human Disease. The International Journal of Biochemistry & Cell Biology, 39(1), 44-84. Retrieved October 7, 2013, from the PubMed database.

Vendemiale, G., Grattagliano, I., & Altomare, E. (1999). An Update on the Role of Free Radicals and Antioxidant Defense in Human Disease. International Journal of Clinical & Laboratory Research, 29(2), 49-55. Retrieved October 6, 2013, from the PubMed database.

Is my sunblock poisonous?!

Ever since I was little, my mom always made sure that I put on sunblock before going outdoors. She correctly believed that the purpose of sunblock was to prevent skin cancer, which according to the American Cancer Society is actually “the most common of all cancers, accounting for nearly half of all cancers in the United States”.  (2013). Now, as a habit, I wear sunblock every day before going outdoors for cross-country practice. My teammates make fun of me for being “paranoid”, but I think that taking precautions is important; I do not want skin cancer! I always argue about the importance of sunscreen. Thus, you can imagine the shock when I read an article called “Your sunscreen might be poisoning you” by Dr. Perry, an Adjunct Associate Professor at Columbia University on the Dr. Oz  TV show website. I was a bit hesitant about the reliability of claims from the Dr. Oz show, (an American TV talk show hosted by Dr. Oz, a teaching professor at Columbia University) since I assume from experience that TV shows are often more for entertainment and may misrepresent the truth. As a result, to clarify whether I have been poisoning myself for sixteen years, I decided to research the chemistry of sunblock: what are some common ingredients? How do they work? And most importantly, do they really harm us?

According to the University of California San Francisco School of Medicine,  there are two types of active ingredients in sun blocks: physical, which “reflect or scatter UV radiation before it reaches your skin” and chemical, which “work by absorbing the energy of UV radiation before it affects your skin.” (2013).

According to Dr. Elizabeth Hale of the Skin Cancer Foundation, the most common physical sunblock used is either zinc oxide or titanium oxide. (n.d.) In a sense, applying them is almost the equivalent of applying white paint, as they literally “block” the sunrays. (Hale, E. n.d.) For example, as seen in the image, zinc oxide is literally a white powder.

Image 1: Zinc Oxide

These physical sunblock ingredients absorb both UVA and UVB rays, which is known as “broad spectrum” (a term you should look for on your sunscreen labeling!) and are large enough particles that they do not enter into your bloodstream. (Hale E., n.d.)Thus, they are both harmless and effective. The drawback, however, is that they are not so visually pleasing unless you want to have a white layer on your face. I researched my own Avene sunblock and found it to be a physical sunblock; it is indeed very white are hard to spread apart—something I found annoying at first, but now I’m glad that at least I’m being effectively protected from the sun.

The consumers’ natural preference of a sunblock that wasn’t so “whitely” visible like a layer of paint on their faces therefore led to the development of chemical sunblock—and this is where the problem begins. One common chemical ingredient is called oxybenzone, which is a chemical that absorbs UV rays. It is so common, that according to a CNN article, “56% of beach and sport sunscreens contain the chemical oxybenzone.” (Dellorto D., 2012).

Image 2: Oxybenzone

Dr. Perry’s article on the possible poisonous effects of sunblock was referring to oxybenzone; he claimed that as an endocrine disruptor (an external compound that disrupts the physiological actions of our body’s natural hormones)(Aguirre C., n.d.), it “can cause abnormal development of fetuses and growing children… early puberty… low sperm counts and infertility… the development of breast and ovarian cancers…prostrate cancer…”. (Perry A., 2013) After reading this, I immediately looked for other sources’ claims on oxybenzone to confirm Dr. Perry’s claim. First, the CNN article referenced before reported that “The American Academy of Dermatology maintains that oxybenzone is safe.” (Dellorto D., 2012) After this, I thought, “Okay, so the government thinks that oxybenzone is safe. Then is this the Environmental Working Group and Dr. Perry crazy?”This is when I came upon an article by Dr. Claudia Aguirre of the International Dermal Institute,  which shed light on the studies causing people to blacklist oxybenzone. One study showed that the harmful effects of oxybenzone were done on rats that were ingesting oxybenzone in toxic amounts. Another study was on whether the chemical would penetrate deep into the dermis in the first place, and although the answer was yes, the study was done on skin samples in a lab—not on human beings. Finally, another study on oxybenzone “saw deleterious effects on humans”, but “the participants were asked to use about 6 times the recommended amount of sunscreen needed to prevent sunburn”. (Aguirre C., n.d.). Thus, in the end, Dr. Perry’s claim is true—but only if you use a crazy amount of sunscreen with oxybenzone.

After doing this research, I learned a lot about sunscreen, and I think it was interesting to research the chemical ingredients in our everyday products. I had always assumed that sunscreen was just some “magical” skin cancer preventer! Also, an important implication from this research is that we should never immediately trust claims made by articles online, even if the author, like Dr. Perry, is an adjunct professor at Columbia University. We should look more in depth into the studies that the claims are based on, and decide whether we want to use these products. Dr. Perry was too extreme in his claim, which confirms my initial assumption that people on TV shows tend to exaggerate and cannot always be trusted. Thus, we have to be careful to what extent we should believe in others’ claims, and of course, we should continue to use sunblock (use the recommended amount of the equivalent of a shotglass, or two tablespoons, to the face and body) (Hale, E., n.d.)!

References:

Aguirre C. (n.d.). Shedding Light on Sun Safety – Part Two Retrieved from http://dermalinstitute.com/us/library/66_article_Shedding_Light_on_Sun_Safety_Part_Two.htm

American Cancer Society. (2013, March 25). Skin Cancer Facts. Retrieved from http://www.cancer.org/cancer/cancercauses/sunanduvexposure/skin-cancer-facts

Dellorto D. (2012, May 16). Avoid sunscreens with potentially harmful ingredients, group warns. Retrieved from http://edition.cnn.com/2012/05/16/health/sunscreen-report/index.html

Hale, E. (n.d.) Ask the Expert: How much sunscreen should I be using on my face and body? Retrieved from http://www.skincancer.org/skin-cancer-information/ask-the-experts/how-much-sunscreen-should-i-be-using-on-my-face-and-body

Perry, A. (2013, May 7). Your Sunscreen Might be Poisoning You. Retrieved from http://www.doctoroz.com/videos/your-sunscreen-might-be-poisoning-you

University of California San Francisco School of Medicine. (2011, June 10). Sunblock. Retrieved from http://www.dermatology.ucsf.edu/skincancer/general/prevention/sunscreen.aspx

Images:

Wikipedia Commons. n.d. Zinc Oxide. Graphic. Retrieved from http://upload.wikimedia.org/wikipedia/commons/1/13/Zinc_oxide.jpg

The Medical Dictionary. n.d. Oxybenzone. Graphic. Retrieved from http://the-medical-dictionary.com/pics/Oxybenzone_1.PNG

Fun in the Sun

I got my first sunburn this summer (ouch) because I forgot to put on sunscreen. Actually, I pretty much forgot to use sun protectant the whole summer. That got me thinking about sunscreen. It’s just something that we rub onto our bodies, so how does it protect our skin? So in this post I’m going to investigate how sunscreen works, why it’s important to protect your skin from the sun, and how to do so.

The reason we need to protect our skin is because of the UV rays that are present in sunlight. UV rays come in wavelengths from 10nm to 400nm, but there are 3 main categories: UVA (315-400nm), UVB (280-315nm), and UVC (100-280nm). UV radiation has “low penetration” so its effects are mainly limited to the skin. (Encyclopædia Britannica, 2013)

(Skin Cancer Foundation, 2013) – diagram of UV ray penetration of skin

UVC rays are completely absorbed by the Earth’s atmosphere, so we don’t need to worry about that. It’s the UVA and UVB rays that cause trouble. UVB rays are the ones responsible for sunburns and suntans. (Everyday Mysteries: Fun Science Facts from the Library of Congress, 2010) UVA rays, since they have a longer wavelength, penetrate deeper and are the main cause of wrinkles and age spots. (Bytesize Science, 2012) UVA rays can also penetrate through clouds and glass, and 99% of the UV rays that reach the Earth’s surface are UVA rays. (Encyclopædia Britannica, 2013) Both UVA and UVB rays can cause skin cancer. (US Food and Drug Administraton, 2011) Also, sun exposure is responsible for 90% of wrinkles! (Youtube, 2013)

To protect ourselves from these UV rays, sunscreens were invented. There are two types of sun protectants available: chemical and physical sunscreens. Physical sunscreens, also known as inorganic sunscreens, are made out of nanoparticles that are approximately 100nm. They act as tiny reflectors on the skin to deflect and scatter the UV rays that shine onto our skin. (PBS Newshour, 2010) The large particle size is also what attributes to the “white cast” look of sunscreen on the skin. (About.com Chemistry, n.d.) Typical ingredients in physical sunscreens are titanium dioxide and zinc oxide.

physical sunscreen

(Bytesize Science, 2012) – structures of titanium dioxide and zinc oxide

Chemical sunscreens, also known as organic sunscreens, are much smaller in size, around 40-50nm. The small sizes of the nanoparticles allow it to be more transparent than physical sunscreens. (PBS Newshour, 2010) The most common ingredients in chemical sunscreens are octinoxate and avobenzone. (Bytesize Science, 2012)

chemical sunscreen

(Bytesize Science, 2012) – skeletal structure of octinoxate and avobenzone

Unlike physical sunscreen, chemical sunscreens protect the skin by absorbing the UV rays instead of reflecting it. The molecules in the sunscreen absorb the high-energy UV photons, and the electrons become “excited.” When the molecule returns to its original state, the energy it absorbed is released as insignificant amounts of heat. This process can be done more than once, in a cycle. (Nonprescription Drug Manufacturers Association and Cosmetic, Toiletry, And Fragrance Association, 1998)

Yikes, those UV rays don’t sound nice at all. In the interest of having younger looking skin, not getting a nasty sunburn, and preventing skin cancer, protecting our skin from the sun is a must. Physical sunscreens can only defend our skin from UVB rays, but chemical sunscreens can protect our skin from both. So when buying sunscreen, look for products that are labeled “broad spectrum” or have a PA value because those indicate both UVB and UVA protection. (Youtube, 2013)

(Youngerberg, 2013) – sunblock that have UVA and UVB protection

SPF, which stands for “sun protection factor,” can be a useful way of determining the effects of sunscreen. If your skin can stand 10 minutes in the sun without burning, then a SPF of 30 will allow your skin to be out in the sun for 30×10, or 300 minutes (5 hours), before burning. (About.com Chemistry, 2010)  Keep in mind that most people don’t put on enough sunscreen (a shot glass worth, or 45mL, of sunscreen is what’s recommended to cover your body), and sweat and water can make the sunscreen less effective, so it is important to reapply sunscreen often (around every 2 hours if you’re active).

It seems that I’ve found the fountain of youth – sunscreen! The next time you’re out in the sun, remember to protect yourself from those pesky UV rays, and do yourself a favor by putting on sunscreen. You’ll thank yourself when you’re older!

References

About.com Chemistry (n.d.). How Does Sunscreen Work?. [online] Retrieved from: http://chemistry.about.com/od/howthingsworkfaqs/f/sunscreen.htm [Accessed: 19 Sep 2013].

About.com Chemistry (2010). How to Choose the Best Sunscreen. [online] Retrieved from: http://cancer.about.com/od/skincancerprevention/a/choosesunscreen.htm [Accessed: 19 Sep 2013].

About.com Pediatrics (2010). SPF – Sun Protection Factor and Sunscreen. [online] Retrieved from: http://pediatrics.about.com/od/pediatricsglossary/g/710_spf.htm [Accessed: 19 Sep 2013].

Bytesize Science (2012). Repelling the Rays: The Chemistry of Sunscreen – Bytesize Science. Available at: http://www.youtube.com/watch?v=wopwVVsbvWI [Accessed: 19 Sep 2013].

Discovery Fit and Health (n.d.). What do SPF numbers mean?. [online] Retrieved from: http://health.howstuffworks.com/skin-care/beauty/sun-care/spf.htm [Accessed: 19 Sep 2013].

Everyday Mysteries: Fun Science Facts from the Library of Congress (2010). How does sunscreen work?. [online] Retrieved from: http://www.loc.gov/rr/scitech/mysteries/sunscreen.html [Accessed: 19 Sep 2013].

Gizmodo (2013). How Sunscreen Works (And Why You’re Wrong About It). [online] Retrieved from: http://gizmodo.com/how-sunscreen-works-and-why-youre-wrong-about-it-508910004 [Accessed: 19 Sep 2013].

Live Science (2010). How Does Sunscreen Work?. [online] Retrieved from: http://www.livescience.com/32666-how-does-sunscreen-work.html [Accessed: 19 Sep 2013].

Nonprescription Drug Manufacturers Association and Cosmetic, Toiletry, And Fragrance Association (1998). Tentative Final Monograph for OTC Sunscreen. [e-book] Food and Drug Administration. Available through: www.fda.gov http://www.fda.gov/ohrms/dockets/dailys/00/Sep00/090600/c000573_10_Attachment_F.pdf [Accessed: 19 Sep 2013].

PBS Newsroom (2010). Just Ask: How Does Sunscreen Work?. [online] Retrieved from: http://www.pbs.org/newshour/rundown/2010/12/just-ask-how-does-sunscreen-work.html [Accessed: 19 Sep 2013].

Science & Engineering News (2002). C&EN: WHAT’S THAT STUFF? – SUNSCREENS. [online] Retrieved from: http://pubs.acs.org/cen/whatstuff/stuff/8025sunscreens.html [Accessed: 19 Sep 2013].

ultraviolet radiation. (2013). In Encyclopædia Britannica. Retrieved from http://school.ebonline.com/levels/high/article/74181

US Food and Drug Administration (2011). How Sunscreen Works. Available at: http://www.youtube.com/watch?v=cC-d9ZsnLds [Accessed: 19 Sep 2013].

Youtube (2013). The Ultimate Guide to Sunscreen. Available at: http://www.youtube.com/watch?v=V46vfg-7dEI [Accessed: 19 Sep 2013].

Images

Bytesize Science (2012). Repelling the Rays: The Chemistry of Sunscreen – Bytesize Science. [image online] Available at: http://youtu.be/wopwVVsbvWI?t=1m32s [Accessed: 19 Sep 2013].

Bytesize Science (2012). Repelling the Rays: The Chemistry of Sunscreen – Bytesize Science. [image online] Available at: http://youtu.be/wopwVVsbvWI?t=1m54s [Accessed: 19 Sep 2013].

Skin Cancer Foundation (2013). Untitled. [image online] Available at: http://www.skincancer.org/Media/Default/Page/prevention/uva-and-uvb/UV-Radiation-and-Skin.jpg [Accessed: 22 Sep 2013].

Youngerberg, E. (2013). Untitled. [image online] Available at: http://3.bp.blogspot.com/-yUMjMYMQdHI/T9tY7Sz0ozI/AAAAAAAAAzw/1bQlGeeBymU/s1600/photo-89.JPG [Accessed: 22 Sep 2013].


Exceptional Bioethanol

One of the videos that particularly struck me from Chemistry class was “Bioethanol,” from the Periodic Table of Videos. In the video, Professor Poliakoff discusses his travels in Brazil, a country known for its high use of ethanol fuel, as well as his discovery regarding the use of bioethanol versus common gasoline. He found that while Brazilians domestically produced an abundant supply of ethanol fuel for use, most citizens continued to use regular gasoline to fuel their cars because it was more cost-effective (meaning that their cars could run on more kilometers per gallon with gasoline than with ethanol, and the difference in price between the two fuels was minimal). Poliakoff then went on to provide an economic explanation for this – because ethanol is fermented from sugar, and because sugar is also consumed in the diet, there is an increasing demand for sugar in both industries. Thus, the costs of producing bioethanol from sugar increase, and in turn, its price as a fuel increases. He then briefly mentioned that an alternative to using sugar in the production of ethanol could be cellulose, a material that is not specifically used for food (Haran, n.d.).Upon mentioning this, he piqued my interest and I decided to further investigate bioethanol and cellulose. This brought me to my question: How is bioethanol manufactured from cellulose, and to what extent is the use of cellulosic ethanol a cost-effective solution to preserve our environment?

(Bioethanol for Sustainable Transport, n.d.)
(Bioethanol for Sustainable Transport, n.d.)

To begin, I conducted background research on bioethanol, otherwise known as ethanol. Ethanol, whose chemical formula is C2H5OH, belongs to the chemical family of alcohols. It is “a colorless liquid and has a strong odor.” (European Biomass Industry Association, n.d.) A number of incentives have fostered the use of ethanol as an alternative fuel source. Among the most pressing of these include the increasing greenhouse gas emissions and harmful pollutants such as carbon monoxide and nitrogen oxide to the environment (Derry et al., 2008), the increasing scarcity of fossil fuel resources, and the growing dependence on foreign imports of oil (CropEnergies AG, 2011). All these concerns for developed countries, such the United States and those in the EU, that result from excessive consumption of fossil fuels contribute to the utilization of ethanol as a cleaner alternative energy source for automobiles. Ethanol releases energy according to the following equation when combusted:

CH3CH2OH (l) + 3O2 (g) –> 2CO2 (g) + 3H2O (g)

(Derry et al., 2008)

There are three main steps in manufacturing ethanol. The first is the formation of “a solution of fermentable sugars,” the second is the “fermentation of these sugars to ethanol,” and the third requires the “separation and purification of the ethanol, usually by distillation.” (Badger, 2002) Traditionally, the fermentable sugars used to produce ethanol come from either sugar crops, such as sugar cane or sugar beet, or cereal crops, such as maize or wheat (European Biomass Industry Association, n.d.). Fermentation of these sugars occurs when microorganisms, such as yeast, ferment the C-6 sugars (commonly glucose) obtained from the crops by using them as food and producing byproducts that include ethanol (Badger, 2002). However, because these sugar crops and cereal crops are also necessary for human consumption, they can be relatively expensive to use for production of ethanol.

(Warner & Mosier, 2008)

So, a third mechanism of developing ethanol for fuel has been developed, using cellulose, the waste residues from forests and the parts of plants that are not needed for food. Also known as Lignocellulosic or Cellulosic bioethanol, this biofuel is considered less expensive and “more energy-efficient than today’s ethanol because it can be made from low-cost feedstocks, including sawdust, forest thinnings, waste paper, grasses, and farm residues (i.e. corn stalks, wheat straw, and rice straw).” (Detchon, 2007) As a person who never likes when things go to waste, I was delighted at the fact that we could create fuel from cellulose, which in turn helps to save so many of our natural resources and eliminate much of our waste. To my dismay, however, I discovered that this advantage is accompanied with many costly limitations.

Cellulose, like starch, is composed of long polymers of glucose, which can be used for fermentation in producing ethanol. However, the structural configuration of cellulose is different from that of starch, and this, combined with its encapsulation by lignin, a material that covers the cellulose molecules, makes hydrolysis of cellulosic materials very difficult because the process requires the aid of enzymes or specific reaction conditions or equipment (Badger, 2002).

(Warner & Mosier, 2008)
(Warner & Mosier, 2008)

The three main methods of cellulosic hydrolysis are acid, thermochemical, and enzymatic hydrolysis (Badger, 2002). For the purposes of this blog post, I will focus on the latter form, involving enzymes, which are “biological catalysts.” Enzymes are introduced into a reaction to provide an alternative pathway with a lower activation energy so that the reaction can take place (Derry et al., 2008). However, enzymes must be able to make contact with the reactants of the reaction, which is quite difficult to achieve with cellulose molecules. Thus, a “pretreatment process” is needed to separate the tightly-bound sugars that comprise cellulose. These processes are often energy-intensive, and are thus associated with high costs (Badger, 2002). In addition, the costs of the enzymes are also currently quite high, although biotechnology research is gradually decreasing their costs (Novozymes, as cited in Detchon, 2007) The National Renewable Energy Laboratory (NREL) uses a process known as simultaneous saccharification and co-fermentation (SSCF) to hydrolyze cellulose. A “dilute acid pretreatment” to “dissolve the crystalline structure” of the cellulose is first employed. A portion of the “slurry” that results is then placed into a vessel that grows a cellulase enzyme, while another portion is placed into another vessel to grow a yeast culture (Badger, 2002). In this process, sugar conversion and fermentation occur simultaneously, rather than consequentially, to yield the product of ethanol as quickly as possible, usually a few days (Lynd, 1999 as cited in Warner & Mosier, 2008). However, SSCF still requires expensive enzymes in order to occur, and because the process lasts a few days, the reactor vessels must run for long periods of time (Badger, 2002).

So, simply from observing the process of SSCF, I realize that the industrial creation of ethanol from cellulose is a tiresome process. The reactions needed to convert a molecule of cellulose into its glucose constituents are both costly and time-consuming, contrary to what I had believed would have been quite simply a breaking down of a polymer of glucose. There are numerous implications to this issue, and this brings me to the second part of my question: to what extent is the use of cellulosic ethanol a cost-effective solution to safeguard the environment? Here I discovered the advantages and disadvantages of cellulosic bioethanol. Firstly, greenhouse gas emissions from ethanol-fueled cars are reduced by 85% to 94% compared to those running on regular gasoline. Cheap feedstock that is non-related to food materials is another added benefit of bioethanol created from cellulose, since the question of food vs. fuel is eliminated. And, much of the infrastructure adapted for ethanol fuel use is already in place – roughly 2,000 stations serving E85 (a fuel containing 85% ethanol and 15% petrol) and most automobiles are already built to run on both gasoline or ethanol-based fuel. What’s even more favorable to the environment from using bioethanol is that because ethanol is an organic compound, it is highly biodegradable, making fuel spills much less hazardous than regular gasoline spills (Green the Future, 2008).

Furthermore, the overall benefits gained from using bioethanol made from any other means also cannot be ignored – for example, lower carbon emissions, less reliance on foreign oil reserves, and conservation of finite fossil fuel resources (CropEnergies AG, 2011).

These pros do no exist without their cons, however. I also found that in addition to the high costs of production of cellulosic ethanol that may make it relatively expensive for consumers, there were other disadvantages as well. Commercialization of this type of ethanol is limited, as most production plants are pilot plants and find it difficult to transition to full-scale commercial plants. In addition, because ethanol absorbs water, it is easily contaminated as a fuel and thus is difficult to transport. The high costs of production also could not be outweighed by ethanol-run automobile performance, since it takes about 1.4 gallons of E85 to run the same distance as it would take 1 gallon of regular gasoline (Green the Future, 2008). This was also the main reason, as stated by Poliakoff, that Brazilians continued to use regular gasoline as opposed to bioethanol – their cars simply ran more efficiently on petrol.

From analyzing both sides of the argument, I have come to the conclusion that even though bioethanol seems to have its many disadvantages, the biofuel has come a long way in improving the welfare of our environment. The implications of a better environment per se are perhaps enough to convince me to purchase ethanol as the source of fuel for my car (when I get one, eventually). But also, because cellulosic materials are often wasted and abundant in nature, I find it simply fascinating that we have come across yet another resource with which to provide energy to sustain our lifestyles. Of course, though, I am careful not to jump to the conclusion that this is a panacea to the global peril of climate change, because I know that exploitation of our environment will lead to destruction of it. But now I have understood that even the smallest of steps taken to achieve ecological sustainability can have drastic rewards for the wellbeing of society.

Sources:

Badger, P.C. (2002). Ethanol from Cellulose: A General Review. Trends in new crops and new uses, 1, 17-21. Retrieved from http://www.hort.purdue.edu/newcrop/ncnu02/v5-017.html

CropEnergies. (2011). Bioethanol report [Brochure/report]. Retrieved from http://www.cropenergies.com/en/Bioethanol/Produktionsverfahren/Bioethanol-Magazin_CE_2011-en_1_1.pdf

Derry, L., Clark, F., Janette, E., Jeffery, F. Jordan, C., Ellett, B., & O’Shea, P. (2008). Chemistry for use with the IB diploma programme: Standard level. Port Melbourne, Victoria: Pearson Education Australia.

Detchon, R. (2007). The Biofuels FAQs: The Facts about biofuels: ethanol from cellulose. Retrieved from http://www.energyfuturecoalition.org/biofuels/fact_ethanol_cellulose.htm

European Biomass Industry Association. (n.d.). Bioethanol Production and use [Brochure]. Retrieved from http://www.erec.org/fileadmin/erec_docs/Projcet_Documents/RESTMAC/Brochure5_Bioethanol_low_res.pdf

Green the Future. (2008). Cellulosic Ethanol: Pros and cons. Retrieved from http://greenthefuture.com/CELLETHANOL_PROSCONS.html

Haran, B (Producer). (n.d.). Bioethanol [Video episode]. United Kingdom: University of Nottingham. Retrieved from http://periodicvideos.com/videos/feature_brazil_bioethanol.htm

Warner, R.E. & Mosier, N.S. (2008). Ethanol from Cellulose Resources. Retrieved from http://bioweb.sungrant.org/Technical/Biofuels/Technologies/Ethanol+Production/Ethanol+from+Cellulose+Resources/Default.htm

Image Sources:

Bioethanol for Sustainable Transport. (n.d.). CO2 cycle for bioethanol [Image]. Retrieved from http://www.best-europe.org/Pages/ContentPage.aspx?id=120

Warner, R.E. & Mosier, N.S. (2008). Fermentation of glucose to carbon dioxide and ethanol [Image]. Retrieved from http://bioweb.sungrant.org/Technical/Biofuels/Technologies/Ethanol+Production/Ethanol+from+Cellulose+Resources/Default.htm

Warner, R.E. & Mosier, N.S. (2008). Structure of cellulose polymer [Image]. Retrieved from http://bioweb.sungrant.org/Technical/Biofuels/Technologies/Ethanol+Production/Ethanol+from+Cellulose+Resources/Default.htm

Analgesic Properties of …. Snail Venom?

I know what you’re probably thinking; snails have venom? This was exactly what I had thought when I came across a post on the popular social media website, Reddit. I was intrigued because I didn’t even know that snails have venoms and that they could even be used as painkillers. Turns out, the post wasn’t referring to the typical snails you find in a garden, but instead, the cone snails that are typically found in warm and tropical seas and oceans. Interested by the topic, I decided to investigate more on how exactly the snail venom can act as an analgesic, and its possible significance in the medical field.
Analgesics are commonly known as painkillers, and are divided into two types, mild and strong. Mild analgesics, such as aspirin and paracetamol, are used to treat the typical headaches, toothaches, or sore throats by, “preventing the stimulation of nerve endings at the site of pain and by inhibiting the release of prostaglandins, the chemical responsible for the widening of blood vessels near the site of the injury, from the site of injury to provide relief to inflammation, fever and pain” (Brown, Ford, 2008). For more severe pains, strong analgesics bind to opioid receptors in the brain to alter the perception of pain by blocking the transmission of pain signals between brain cells (Brown, Ford, 2008). Today, many cancer patients, diabetic patients, and other victims of chronic pain are treated with strong analgesics like morphine and heroine. The problem is that these opioids are highly addictive and repeated usage can lead to tolerance, which a reduced response to the drug. Scientists have discovered that the venom found in cone snails have analgesic properties that are 10000 times more powerful than morphine, and the best part about the venom is that it is not addictive. (National Geographic, n.d.) Since cone snail venom is clearly a better analgesic than opioids, I questioned why isn’t it replacing morphine and heroine as the common analgesics to treat victims with chronic pain?
deadly cone

Figure 1: Image of a Marble Cone Snail (National Geographic, (n.d.))

Although they are only about four to six inches long, these carnivorous mollusks they have venoms poisonous enough to kill 15 adult human beings (Compassionate Healthcare Network, 2004). To do this, the cone snails have teeth that are similar to hypodermic needles that inject venom into their preys. The venom instantly paralyzes the victims by interfering with the communications of the nervous systems. In a typical nervous system, the neurons transmit chemical signals to another neuron through ion channels. The chemical signals are repeatedly transmitted from neuron to neuron until it reaches a muscle cell and tells it to contract. The venom of cone snails contain hundreds of thousands of short polypeptide proteins that blocks specific ion channels to prevent neurons from transmitting chemical signals, inhibiting muscle movement, leading to paralysis (Chadwick, 2013)(Discovery News, 2013).
So how can something so deadly be beneficial to humans? For many years, scientists have studied several hundreds of the short polypeptide proteins, called conotoxins, before the isolating analgesic conotoxin agent and creating the synthetic version named Ziconotide, or often known by the name Prialt. Unlike other analgesics, Ziconotide inhibits pain in a different way. People feel pain because electrical signals are carried across a synapse from the pain fibers to the nerve cells in the spinal cord that signals the brain. In order for the electrical signals to cross the synapses, electrical signals has to be converted into a chemical signal with the help of calcium. Ziconotide blocks the calcium gateways in the nerve fibers so that the chemical signals cannot cross the synapse to reach the nerve cells in the spinal cord. As a result, the brain does not receive the signal and therefore, one does not perceive pain (Compassionate Healthcare Network, 2004).
Although Ziconotide is 10000 times more powerful than morphine and is non-addictive, it is not commonly use to treat patients with chronic pain. This is because like any other drug, Ziconotide comes with many side effects such as abnormal vision, amnesia, vertigo, anxiety and possibly more undiscovered side effects. Furthermore, ziconotide cannot be administered orally because the body will break down the swallowed ziconotide before it can reach the receptors they need to reach. Therefore, zinconotide is currently administered with a direct injection into the spinal cord, a costly and invasive method of drug delivery.
107452-89-1

Figure 2: Structure of Ziconotide (ChemBlink, (n.d.))

The discovery of Ziconotide has many implications in the medical field. Firstly, future research can be synthesized or modified Ziconotide to withstand the digestive processes of the body so that zinconotide can be taken more conveniently and without economic strain. In fact, scientists have already engineered a circular shaped synthetic Ziconotide conotoxin that is more stable to be administered orally (Discovery News, 2013). Ziconotide that can be administered orally will be more accessible to patients with chronic pain that have developed tolerance to morphine and heroine and need stronger analgesics to suppress the pain. Secondly, the discovery of Ziconotide suggest a bigger picture that many medical issues that people face today could possibly be cured by something in nature. There are so many microorganisms, animals and plants on Earth that have not yet been discovered. Perhaps, the secret to the cures of cancer and other illnesses lie in the Amazon jungle or at the bottom of the Mirana Trench.

References:
Brown, C., Ford, M. (2008). Higher Level Chemistry Developed Specifically for
the IB Diploma. England: Pearson Education Limited.

Chadwick, A. (2013). Venom. The Cone Snail. Retrieved September 5, 2013, from
http://www.theconesnail.com/explore-cone-snails/venom

Compassionate Healthcare Network. (2004). Cone Snail Venom Attacking Pain.
Compassionate Healthcare Network. Retrieved September 5, 2013 from http://www.chninternational.com/cone_snail_venom_attacking_pain.htm

Discovery News. (2013, February 11). Snail Venom Inspires Powerful Pain
Reliever. Discovery News. Retrieved September 5, 2013, from http://news.discovery.com/human/snail-venom-painkiller.htm

National Geographic. (n.d.). Geographic Cone Snail. National Geographic.
Retrieved September 5, 2013, from http://animals.nationalgeographic.com/animals/invertebrates/geographers-cone-snail/

Marble Cone Snail [Web Graphic]. (n.d.) Retrieved September 5, 2013 from http://lhs204.stellpflug.com/Period%202/Canutito%20Payan/Marble%20cone%20snail.html

Wikipedia. (n.d.). Conus. Wikipedia. Retrieved September 5, 2013 from
http://en.wikipedia.org/wiki/Conus

Wikipedia. (n.d.). Zinconotide. Wikipedia. Retrieved September 5, 2013 from
http://en.wikipedia.org/wiki/Ziconotide

Ziconotide Acetate [Web Graphic]. (n.d.). Retrieved September 5, 2013 from http://www.chemblink.com/products/107452-89-1.htm

Hair Die?

Since I was a kid, I’ve always been fascinated with hair dyes and have always dreamed of having my hair dyed purple. However, I’ve always heard people say that hair dye is very bad for one’s hair but I’ve never really thought about the chemistry behind it. So my question is: to what extent is hair dye safe for us to use?

In order to fully understand how hair dye works, I first asked myself: how exactly does hair colouring work? Hair colouring works when chemical reaction occurs between the hair molecules and pigments with peroxide and ammonia found in the hair dye itself. When dyeing hair, the cuticles found in the outer layer of the hair must first be opened with ammonia in order for the hair colour to be able to penetrate into the cortex of the hair. After the cuticles are open, there’s usually a two-step process that happens simultaneously, removing the original pigments in the hair using peroxide and depositing in couplers, which are chemical compounds that define the colour of the hair dye. Lastly, conditioners are use to close off the hair cuticles to seal in and protect the new colour. (Helmenstine, 2013)

Hair Couplers
Hair Couplers

(Wikipedia, 2013)

Even though the first commercial and “safe” hair dye was produced in 1909 and over 75% of American women dye their hair, but to what extent is hair dye safe for us to use? Studies have shown that there’s a strong positive correlation between older hair dyes and cancer as the old compounds that made up the couplers were carcinogenic. However ever since they were identified, companies have altered the compounds for these couplers and they are no longer a problem anymore. But since then, new studies have also emerged showing that the new dyes may be indirectly causing cancer too. Researchers have found out that chemicals called secondary amines, which are found in all permanent hair dyes, are able to penetrate into our skin and hair, and remain there for up to years after the dyes are applied. Over time these secondary amines could react with tobacco smoke, exhaust fumes, or other substances to form a highly poisonous chemical known as N-nitrosamines. (Brown Girl, 2013)

Secondary Amines
Secondary Amines

(Wikipedia, 2013)

N-nitrosamines
N-nitrosamines

(Wikipedia, 2013)

At the same time, hair dye is known to irritate the skin and cause skin discolouration due to the fact that our skin is also made up of the same type of keratinized protein as hair. However, this discolouration typically disappears within a few days as the skin naturally renews itself. Hence, a good way to prevent the discolouration of the skin is to apply a thin layer of petroleum jelly and wear latex gloves to protect the hands. (Wikipedia, 2013)

In conclusion, although the old hair dye problems have been solved, new problems are still arising and shouldn’t be ignored. So to be on the safe side, one can use hair dye, but just use it with caution, and don’t apply it regularly as it allows the build up of these secondary amines.

Bibliography:
– Helmenstine, A. M., & Ph.D.. (n.d.). Hair Color Chemistry – How Haircoloring Works. About.com Chemistry – Chemistry Projects, Homework Help, Periodic Table. Retrieved September 1, 2013, from http://chemistry.about.com/cs/howthingswork/a/aa101203a.htm
– Hair coloring – Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the free encyclopedia. Retrieved September 1, 2013, from http://en.wikipedia.org/wiki/Hair_coloring
– Amine – Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the free encyclopedia. Retrieved September 1, 2013, from http://en.wikipedia.org/wiki/Amine
– Nitrosamine – Wikipedia, the free encyclopedia. (n.d.). Wikipedia, the free encyclopedia. Retrieved September 1, 2013, from http://en.wikipedia.org/wiki/Nitrosamine
– Column of Controversy: Hair Dye vs. Cancer | Brown Girl Magazine. (n.d.). Brown Girl Magazine | The Premier Magazine for Young South Asian Women. Retrieved September 1, 2013, from http://browngirlmagazine.com/2013/05/column-of-controversy-hair-dye-vs-cancer/

Wait, A New Element?

So while I was reading the news, I happened to discover a page titled ‘Existence of New Element Confirmed’. That got me to wonder, was there really a new element discovered? It turns out, researches at Lund University has confirmed that a new element with the atomic number 115 exists, temporarily named Ununpentium (Uup abbreviation). Currently, the name is being debated by the International Union of Pure Applied Chemistry (IUPAC). The research verified findings of the same element during a prior experiment performed in 2004 led by a Russian research team (“Existence of New Element“, 2013). Both research teams performed the same experiment; calcium-48 ions were bombarded at a thin film of americium-243. The collision of the ions and atoms resulted in a formation unupentium, which decayed milliseconds later due to its radioactive nature (“Ununpentium“, n.d.). Although this begs the question “how was this element confirmed to exist”, analysis of  the energy released through radiation matched the theoretical values of the element confirming its existence (“Existence of New Element“, 2013).

Ununpentium Bohr Model
Ununpentium Bohr Model

That got me to ponder, what chemical/physical properties does this new element have? Unfortunately, it is currently impossible to give a definitive answer to that. Every isotope of Uup that has been discovered all have an average half-life of 100ms. That means a large enough sample cannot be collected to observe the element’s properties. However, it is predicted that the element has similar properties to that of the group 5 elements on the periodic table (“Ununpentium“, n.d.). Uup is classified as a synthetic element, elements which have a half-lives so short relative to the Earth’s age, that most or all naturally occurring elements would have decayed completely (“Synthetic Element“, n.d.). The majority of them lie within period 7 of the periodic table.

Synthetic Elements
Synthetic Elements

So why discover new elements if they decay so quickly? Not the most moral or conventional example but plutonium, an element discovered in 1941 and was used in the atomic bomb dropped on Nagasaki (“Plutonium“, 2012). Since most of the synthetic elements are all radioactive, the majority of the are used for nuclear weapons. On a more accepted aspect of usage, plutonium is used in nuclear reactors to provide electrical energy for cities around the world (“Nuclear Reactors“, 2013). Atomic energy is considered clean as it doesn’t produce air pollutants through usage and can be used as an alternative to fossil fuel burning. However, disasters such as the recent Fukushima earthquake in 2011 and the Chernobyl meltdown in 1986 serves as a constant reminder and strong argument against atomic energy.

I want to highlight the importance of the scientific method here. The original research experiment performed in 2004 produced quantifiable results. At the time, technology could not confirm such results found. The important thing was the experiment set up was reproducible in another lab. With more advanced technology and further research into the theoretical data was the reason why the team at Lund University could confirm results. Without a reproducible experiment, a scientific claim cannot be verified.

Works Cited

“Existence of New Element Confirmed.” ScienceDaily. Lund University, 27 Aug. 2013. Web. 28 Aug. 2013. <http://www.sciencedaily.com/releases/2013/08/130827091636.htm>.

“Nuclear Reactors.” World Nuclear Association. N.p., July. 2013. Web. 28 Aug. 2013. <http://world-nuclear.org/info/Nuclear-Fuel-Cycle/Power-Reactors/Nuclear-Power-Reactors/#.Uh3uPxsSZVV>.

“Plutonium.” US Environmental Protection Agency. N.p., 6 March. 2012. Web. 28 Aug. 2013. <http://www.epa.gov/radiation/radionuclides/plutonium.html>.

“Synthetic Element.” Princeton University. N.p., n.d. Web. 28 Aug. 2013. <http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Synthetic_element.html>.

“Ununpentium.” Wikipedia. N.p., n.d. Web. 28 Aug. 2013. <http://en.wikipedia.org/wiki/Ununpentium>.

Anesthesia, Safe or Not?

Throughout my life I’ve had a couple of surgeries. Every time I have received surgery, my mother always asked the doctor, “Do you have to use general anesthesia?”. In times like that I have always told myself, why does my mom even ask, of course the doctors are going to use general anesthesia, why not?  One day I asked my mother “Why do you ask the doctors the same question every time?”, and she told me that general anesthesia was very dangerous, and if it is unnecessary it would be better not to use it. This is why I chose to research general anesthesia. I would like to formulate my own conclusions about the dangers of general anesthesia. The way I will do this is through a careful analysis of the facts, side effects and the way general anesthesia works. I will also use my knowledge of chemistry to aid me in making my conclusion.

The functions of anesthesia include: analgesia (no pain), amnesia (loss of consciousness), impairment of skeletal muscle, and weakened autonomic responses. The most important part of anesthesia is that after the surgery all of these effects can be reversed.  Not all anesthetics will provide all of these effects. For example, barbiturates are not analgesics, but will bring loss of consciousness. This is often why most anesthesias are a combination of many anesthetics.

Anesthetics have many side effects. The first one is a decrease in respiration. Anesthesiologists deal with this by attaching all patients to ventilators during surgery. The second most common side effect is nausea, when a patient is under general anesthesia, their lower esophageal sphincter is relaxed. To avoid death by aspiration, doctors use endotracheal tubes to provide ventilation.

Endotracheal tube

Picture 1: Endotracheal Tube

The third side effect is hypothermia. To prevent this side effect is one of the major goals for anesthesiologists. Anesthesiologists prevent hypothermia by warming the fluids (anesthesia), which are injected into the human body.

How does anesthesia work? Anesthetics block certain protein receptors, inhibiting the protein from performing its task. For example, the NMDA (N-methyl-D-aspartate) receptor is one of the main mediators of excitatory neurotransmission. The receptor is an ion channel, which permits the movement of calcium, sodium and potassium across the post-synaptic membrane. Anesthesiologists inhibit this protein receptor by depolarizing the cell with the anesthesia, which then results in the protein receptor not completing its task. Anesthesia depolarizes the cell inducing the cell with a net positive charge.  (Gambulos)

NMDA receptor

Picture 2: NMDA Receptor

The Ca2+ and Na+ enter the cell and induce a net increase of 3+. The anesthesias, which are involved, are Xenon, Ketamine (C13H16ClNO), and nitrous oxide (N2O). (Gambulos)

Anesthesias are really useful in putting you to “sleep”, but once surgery is over and you wake up you don’t want these chemicals to linger around in your body.This diagram shows how propofol (C12H18O) interacts with your metabolism in order to exit the human body.

Propofol and your metabolism

Picture 3: Propofol exiting the body

The propofol interacts with the liver glucuronate and sulfate conjugation. Then is excreted into the urine to exit the body. Usually 70% of the propofol is gone in 24 hours, and about 90% is gone in 5 days.

Before I started this blog assignment I thought anesthesia was the “simple” part of surgery. After doing all this research I have realized that the anesthesiologists must consider many things before using an anesthesia.  For example, if the anesthesia will interact correctly with the patients protein receptors. The anesthesiologist’s job doesn’t stop there, while the patient is “under” they must ensure that they are ready to deal with any side affects that might occur from the anesthesia, and after surgery is complete the anesthesiologist must then ensure that the anesthesia administered must exit the human body safely.

In conclusion, general anesthesia is safe. The side effects are all dealt with appropriately. For example, the hypothermia is dealt with warm anesthesia pumped through your veins. After examining the way anesthesia works, obstructing the function of protein receptors, I have realized that drugs work the same way. The reason why drugs are so dangerous is because often it is difficult to stay within the therapeutic window. Anesthesiologist deals with this by constantly staying by your side, ensuring that the drugs in your system do not exceed the toxic level or go under the therapeutic level. Finally the last part of anesthesia is the way it exits your body. Your body does this through a reaction of the anesthetics with your liver glucuronate and sulfate conjugation. Then the anesthetic proceeds to your urine. At first I thought this was dangerous, but then I remembered that almost every adult drinks alcohol, and 90% of the ethanol, from alcohol, is broken down by your liver. Therefore I concluded that the way anesthesia leaves your body is not so dangerous after all.

References

Garcia, Paul, Scott Kolesky, and Andrew Jenkins. “General Anesthetic Actions on GABAA Receptors .” PMC. Bentham Science Publishers, n.d. Web. 25 Mar 2013. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2866459/>.

Gambulos, Rachel. N.p., 20 04 2008. Web. 25 Mar 2013.

Gordon, G. (2010, August 31). Propofol-3. Retrieved from http://www.anesthesiawiki.net/metrohealthanesthesia/MHAnes/edu/ivanes/propofol3.htm

Lundbeck Institute. (n.d.). Nmda receptor, showing different subtypes. Retrieved from http://www.cnsforum.com/imagebank/item/hrl_rcpt_sys_NMDA/default.aspx

Oda, Yutaka. Hamoka, N. Hiroi, T., Imaoka, S., Hase, I., Tanaka K., Funae Y., Involvement of Human Liver Cytochrome P4502B6 in the metabolism of Propofol. The British Journal of Pharmacology. 51. 281-285. 2001.

Thomas, Shawn. Drug Reference for FDA Approved General Anesthetics @ Neurotransmitter.net. 2007.

The Alkaline Diet

After reading Nicholas’ post on the claim made by the company that produced water ionizers, I was reminded of a similar claim made by advocates of the ‘Alkaline Diet’. I decided to investigate whether these claims were accurate, or like the ones made by the water-ionizer company, scientifically wrong.

The Alkaline Diet is based on the theory that eating specific foods can affect maintenance of the body’s ideal pH balance, and improve health. (Collins & Chang, n.d) A website promoting holistic treatments gave the following reasoning for the diet:

The pH of the blood must always fall between 7.35 and 7.45  (slightly alkaline) to ensure an appropriate concentration of oxygen in the blood. A pH lower than 7.35 (Acidosis) may portray the beginnings of a disease / aging, while a pH higher than 7.45 (Alkalosis) would result in seizure, and a possible coma.

In order to keep the blood within this pH range, the website then explains, 75% of alkaline forming foods must be consumed; however, the American diet consists of 80% of acid forming foods.

The body creates a buffering system in order to counteract this abundance of acidic food in the diet; this buffering system runs on electrolytes, which are important for the metabolic functioning of body systems. Adequate electrolyte supply will pose no problem on the buffer system, however a shortage of these electrolytes will make it difficult for the body to maintain homeostasis (a state of equilibrium). A shortage of electrolytes usually occurs as a cause of excessive consumption of acid forming foods. (Frequency Rising, n.d)

At first, this claim made sense to me. After all, medical websites confirm that the blood’s pH must fall within a certain range. (Collins & Chang, n.d) Furthermore, there is evidence that shows that the concentration of Oxygen in the blood is affected by the blood’s pH, and as I have previously learnt in Biology class, it is true that the pH of blood must remain within a certain range to ensure health.  (RSC, n.d) Another medical website mentioned diseases such as Acidosis and Alkalosis, the former caused by a blood pH lower than what it should be, and another caused by a blood pH higher than it should be. (Dugdale & Zieve, n.d) Was the claim made by the holistic website accurate? Upon further examination and reflection, it was clear to me what the problem was: the holistic website was trying to convince people on the basis of a logical fallacy!* Our body deals with acidic food with a buffer system that does not work properly when you consume excessive acidic foods?

What?

That makes no sense.

I soon realized that it was very easy to see the reason they would make this claim, as directly under the article, I saw this.

Water Ionizer Advertisement

This reminded me of Nicholas’ post, and confirmed my doubts: it was all just a marketing technique.

I decided to look at the biochemistry myself to determine the validity of the diet.

I found the concentration of Oxygen in the blood is controlled by a separate mechanism: oxygen flows around the body in blood by hemoglobin, a complex molecule with a central ion. (AUS-e-TUTE, n.d) The oxygenation of blood is an equilibrium reaction:

Hb4(aq) + 4O2(aq) <–> Hb4O8(aq)

A number of equilibrium reactions involving hemoglobin are responsible for the buffering of the blood: the net reaction being –

HbH+(aq) + O2(aq) <–> HbO2(aq) + H+(aq)

Metabolic reactions in the body release many acidic compounds, which lowers the blood’s pH by increasing the concentration of H+ ions present in the blood. This in turn, forces the equilibrium position to the left, resulting in acidosis. This decrease in oxygen supply causes fatigue and headaches. Acidosis is also the same condition you experience temporarily when you exercise without warming up, or when you engage in strenuous exercise when the available supply of oxygen cannot meet the demand for energy to complete the oxidation of glucose to carbon dioxide. (AUS-e-TUTE, n.d)

Thus, Acidosis really has nothing to do with what you eat.

Additionally, although electrolytes are important for the body, the only ion that affects the pH of the blood is the Phosphate Ion (PO42-), which is part of the Phosphate Buffer System. (Electrolytes, n.d) However, the primary buffer system for balance of the blood pH’s remains the Hydrogen Carbonate Buffer System.

Hydrogen Carbonate is produced in the body with water and CO2 (the end product of cellular metabolism) with the following reaction:

H2O + CO2 <–> H2CO3(aq)

The Hydrogen Carbonate is then involved in another (can be classified as a Bronsted-Lewry) reaction, which produces bicarbonate and the Hydronium ion:

H2CO3 + H2O <–> H3O+ + HCO3

If there is excess acid in the body (H3O+), the equilibrium shifts left.

H2CO3 + H2O <–  H3O+ + HCO3

Thus, the excess acid is neutralized by the base (HCO3)

The reverse takes place if there is excess base (OH) in the body: this reacts with the carbonic acid (H2CO3) and the equilibrium shifts right.

H2CO3 + OH <–  H2O + HCO3

This system thus operates under Le Chaletier’s principle, which states that “if a chemical system at equilibrium experiences a change in concentration, temperature, or total pressure, the equilibrium will shift in order to minimize that change ”. This reaction is the main mechanism used by our body to maintain homeostasis.

The Phosphate Buffer System plays a role in plasma and erythrocytes (components of blood)- (Tamarkin, n.d)

H2PO4- + H2O <–> H3O+ + HPO42-

Any excess acid reacts with monohydrogen phosphate to form dihydrogen phosphate –

H2PO4- + H2O <– H3O+ + HPO42-

Similarly, excess base is neutralized by dihydrogen phosphate –

H2PO4- + H2O –> H3O+ + HPO42-

So if this is all true, and the claim that eating alkaline foods can affect blood’s pH is not correct, then why do people continue to follow the Alkaline diet: and how can we explain their success stories?

The Alkaline Diet is “a diet of fresh fruits and vegetables, plenty of water, avoiding processed foods, coffee, and alcohol, which are all recommendations for a generally healthy diet anyway,” says Marjorie Nolan, who is an American Dietetic Association spokeswoman. (Collins & Chang, n.d) This is evident by an Alkaline Diet cheat sheet, which recommends eating cold-pressed olive oil instead of butter, frozen fruit instead of canned fruit, sparkling water instead of soda, honey instead of sugar, and so on. (Wilkinson, n.d) According to Nolan, any diet consisting of this meal plan is bound to prove successful, because it is “basically healthy”. She confirms however, that the body “regulates our pH between 7.35 and 7.45 no matter how we eat.” (Collins & Chang, n.d)

Alkaline Diet for Dummies: Cheat Sheet

Alkaline Diet for Dummies: Cheat Sheet

Alkaline Diet for Dummies: Cheat Sheet

So, what are the implications of this finding?


First, the negative implications: because the Alkaline diets promotes less consumption of dairy products and animal fats, followers of the diet if not careful, may develop calcium and protein deficiencies, according to John Asplin, an MD and kidney specialist. (Collins & Chang, n.d) A vegetarian myself, I was quick to disagree with this statement in my mind, however, he acknowledged that “vegetarians can be completely healthy in their diets, as long as they make sure to get adequate supplies of essential components to a diet.” Asplin also asserted that this could be seen as benefit also, because “many Americans over-consume protein”. (Collins & Chang, n.d) Another implication of this finding is that followers of the Alkaline Diet may not have a scientifically correct view of the functioning of their body, and this could lead to potential problems in the future. Followers of the diet may also waste money on expensive products (such as the water ionizer advertised on the holistic website) that do not affect our body in the way that the manufacturers claim.

What are the benefits? Because excess animal protein results in a higher risk of developing kidney stones, “eating a diet rich in vegetables, as with the alkaline diet” can lower this risk, according to Asplin. (Collins & Chang, n.d) It has also been suggested by research that an alkaline diet may slow bone loss and muscle waste, increase the growth hormone, and reduce the risk of certain chronic diseases (these are correlations however, and cannot be stated as a cause-effect relationship). (Schwalfenberg, 2011)

A negative correlation between the alkaline diet and incidence of cancer has also been shown, however the same results were obtained when the vegetarian diet was measured against cancer rates: additionally, as the study was correlational, there were many confounding variables that may have affected the results such exercise, alcohol consumption, smoking, genetics, etc. (Collins & Chang, n.d)

Nolan speaks of this finding, stating that “clinical studies have proved without a doubt that people who eat more fresh fruits and vegetables and hydrate properly do have lower rates of cancer and other diseases”, but that “it probably has nothing to do with blood pH”. (Collins & Chang, n.d)

The journey I took while examining this diet taught me to properly examine the agenda of the source making a claim before choosing to accept it: because the holistic website was advertising the water ionizer, they made claims that were scientifically inaccurate to make the product seem more appealing to customers. Web MD on the other hand, a medical website dedicated to providing people with factual information on clinical practices, provides evidence and information that supports the knowledge we have of the biochemistry of our body.

Thus, William Mundel, the vice chair of the department of General Internal Medicine at the Mayo Clinic in Rochester, advises against diets that “want you to buy only their product” (i.e.: the water ionizer), “focus on a narrow spectrum of foods” (i.e.: eliminate all animal fats), and “claim that science has kept something secret, or that someone has discovered something that nobody else knows about”. These are the types of diets that tend to be scientifically wrong. (Collins & Chang, n.d)

* The logical fallacy used is Circular Reasoning / Begging the Question.

References

Chemical Buffer Systems- Acid-Base Balance. (n.d.). Boundless. Retrieved May 22, 2013, from https://www.boundless.com/physiology/fluids-and-acid-base-balance/acid-base-balance/chemical-buffer-systems/

Chemistry Tutorial : Oxygen Transport in Blood. (n.d.). AUS-e-TUTE For Astute Science Students. Retrieved May 22, 2013, from http://www.ausetute.com.au/blood.html

Chemistry for Biologists: Transport of Oxygen in the Blood. (n.d.). Royal Society of Chemistry | Advancing the Chemical Sciences. Retrieved May 22, 2013, from http://www.rsc.org/Education/Teachers/Resources/cfb/transport.htm

Collins, S., & Chang, L. (n.d.). Alkaline Diet: Pros, Cons, and Do They Really Affect Acid Levels in the Body?. WebMD. Retrieved May 22, 2013, from http://www.webmd.com/diet/features/alkaline-diets-what-to-know

Dugdale, D., & Zieve, D. (n.d.). Alkalosis – Symptoms, Diagnosis, Treatment of Alkalosis – NY Times Health Information . Health News – The New York Times. Retrieved May 22, 2013, from http://health.nytimes.com/health/guides/disease/alkalosis/overview.html

Life Balances: Electrolytes. (n.d.). John Kitkoski’s Life Balances Program: Home Page. Retrieved May 22, 2013, from http://www.lifebalancesprogram.com/Library/Electrolytes.html

Schwalfenberg, G. (2011, October 12). The Alkaline Diet: Is There Evidence That an Alkaline pH Diet Benefits Health?. National Center for Biotechnology Information. Retrieved May 22, 2013, from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3195546/

Tamarkin, D. (n.d.). Buffers. STCC Faculty Webpages. Retrieved May 22, 2013, from http://faculty.stcc.edu/AandP/AP/AP2pages/Units21to23/ph/buffers.htm

Wilkinson, J. (n.d.). Acid Alkaline Diet For Dummies – Cheat Sheet. For Dummies . Retrieved May 20, 2013, from http://www.dummies.com/how-to/content/acid-alkaline-diet-for-dummies-cheat-sheet.html

pH balance. (n.d.). Frequency Rising – Alternative Medicine and Holistic Health Products. Retrieved May 22, 2013, from http://www.frequencyrising.com/pH.htm