Archive for December 2012

‘Tis the Season for Science! (Isn’t it Always?)

Now that I’ve had a chance to recuperate from pre-exam stress, exam stress, and post-exam stress, I’m enjoying the holiday season and all that goes with it. A break from school and chemistry courses does not, of course, keep me from doing science-y things. As with any time of year, the holidays are full of cool chemistry that we often take for granted. For example, candy canes. Yes. Candy canes. Now, I’m not personally a fan of exposing my tongue to shards of crystallized sugar, but so many people take the risk that it got me wondering. What’s the benefit? Sure, there’s sugar, the usual culprit that satisfies our sweet toothes. I’ve always been told that chewing gum during a test is beneficial. When I was in high school, my teachers would hand out gum or peppermints as they handed out the tests. Hmmm, I wondered. Does peppermint really help you do better on tests?

Before the Chocolate and Peanut Butter Were Combined

In this post, I want to talk about peppermint, but I also want to talk about being scientific. I happen to study chemistry, but anyone can discover the world through observations, research and simple experiments. I’ve read a number of scientific journals, articles, papers, and reports that reach conclusions based on very methodical, but very, um, interesting (amusing?) tests. The latest one I read was this paper published by the Sense of Smell Institute (about peppermint). They included experiments like having a bunch of people see how many letters they can memorize in a room that smells like peppermint, as compared to how many letters they can memorize in a normal smelling room. Others I’ve read include this one about the efficacy of ginger for nausea prevention, in which volunteers are essentially blindfolded and spun around in a slightly-off kilter chair until they vomit. The funny thing about science and research is that  frequently the only way to figure something out is to come up with a creative way to test it. It’s not all fancy equipment, calculus, and electron microscopes, but more often ingenuity on the part of scientists, and anyone can be a scientist.

Chemical Structure of Menthol, A Major Component of Peppermint

Anyway, back to the red and white striped stuff. Peppermint is one of those plants that’s been used for pretty much everything for pretty much ever. People use the leaves, oils and other products of the plant to treat conditions as common as stomach aches and as complicated as muscle spasms and fevers. It turns out that it actually does most of the things people think it does. The researchers at the above mentioned Sense of Smell Institute compiled a number of studies showing that peppermint does, in fact, have a positive effect on, “enhancing mental performance and cognitive functioning, pain threshold and tolerance, digestion and digestive processes, and athletic performance.” The article is easy to read and well written, so I definitely recommend checking it out (you know, to expose yourself to some bonus science stuff.) Here’s the link again. Research articles aren’t all scary. What chemical compounds are in peppermint that make ingesting or rubbing it on your skin beneficial? For one, peppermint is a stimulant, like caffeine. Stimulants are substances that increase your brain or muscle activity. Stimulants work by tricking your brain into thinking you’re in a sticky situation, like, being attacked by a bear.   They cause your body to breakdown nutrients for energy faster than normal, so you can use the immediate energy to fight back, or run away really fast (see: fight or flight response). This is why caffeine is typically a major ingredient in diet pills – they force your body into an unnatural overdrive.  Substances that we ingest, like coffee, chocolate or peppermint contain compounds with chemical structures that resemble stimulants our brains make naturally, like adrenaline. Stimulants have even been shown to improve physical performanceas a result of the boost they provide. Obviously, there are downfalls of artificially energizing your brain, like headaches, difficulty sleeping, and that increased sense of gravity on your eyelids when you skip the morning joe.

 Remember when I talked about how there are little uniquely-shaped receptors in your nose that match up with little uniquely-shaped smelly molecules? The same thing happens in your brain. Chemicals that are similar enough to ones our brains make regularly produce similar physical effects. It’s like only having raspberry jam when you want strawberry jam. You can make a PB&J with either. So, if you’re directing your focus to, say, a calculus exam while chewing peppermint gum, your brain is being slightly stimulated by compounds in the peppermint that work similarly to adrenaline or caffeine (and I think most college students understand the benefits of caffeine before an exam). Instead solving the dilemma of being attacked by a bear, your extra energy can be committed to answering the next question. Try a peppermint or candy cane before your next test or work out, and see if you notice a difference. Worst case scenario? Fresh breath.

 

As a bonus, here’s a recipe for candy canes in science-speak (from the American Chemical Society):

Construction of Variegated Disaccharide “J” Tubes

Special Technical Experiment for Advanced Chemistry Students

Purpose: To observe the effect of torsion on the visible configuration of certain groups of macromolecules.

Apparatus:
400 mL beaker, Bunsen burner, Graduated cylinder, Paraffin coated paper, stirring rod, ring stand, set-up thermometer
Materials:
Potassium hydrogen tartrate (CHC4H4O6), Mentha peperita extract, Hydrogenated vegetable oil, Plant starch (C6H10O5), Edible pigments, Sucrose (C12H22O11)
Procedure:
  1. Add 145 g sucrose, 35 g starch, 40 mL water, and .5 g potassium hydrogen tartrate to a 400 mL beaker. Thoroughly mix with a stirring rod.
  2. When a uniform mixture is achieved, subject the mixture to intense heat from the nearest source of C3H8. When the mixture begins to boil, lower the flame. During the operation (approximately 20 minutes) avoid stirring because any external agitation will be detrimental to the desired effect.
  3. The quantity of heat is proportional to the viscosity of the product. This is an important factor in determining the end point of the reaction. When the thermometer reaches 132 degrees Celsius, sufficient heat has been added. Remove the burner.
  4. Add plant extract (approximately 2 mLs) and stir. Pour one-half of the mixture onto the paraffin-coated paper which has been lubricated with hydrogenated vegetable oil. Then melt, by friction, some of the lubricant in your palms. The paraffin-coated paper should be placed on top of paper towels to prevent the paraffin from melting onto the table top. To the portion of the mixture remaining in the beaker, add 1 mL of red pigment. Now pour the colored mixture onto another piece of lubricated paraffin paper.
When the mixture has cooled to a tolerable heat, initiate torsion on both portions to counter their tensile strength. Continue to stretch with both hands until the desired tensile strength is reached. Divide each color into four 8 inch segments. When ready, combine one non-pigmented segment with a pigmented segment. Do so with torsion. Place the distortions on a clean section of paraffin-coated paper and shape them into “J” conformations. Permit the final product to remain undisturbed until the molecules become adapted to this position.
Analysis: Perform a critical taste test comparing your product with a commercially synthesized product.

As always, thanks for reading, 

-Ashley

Sources: stimulant. (2008). In The Columbia Encyclopedia. Retrieved from http://ripley.sbc.edu:2680/entry/columency/stimulant

http://www.chemistryexplained.com/St-Te/Stimulants.html#b

 

Be Sure to Eat Your…..Anti-Oxidants!

People are always talking about what foods have the most anti-oxidants. What does that mean, exactly? Perhaps more importantly, does it mean anything? Or, is it just more health-crazed nonsense? As it turns out (this time), it’s not a load of B.S. So, what is it? Surprise! It’s chemistry! Yay!

Sometimes molecules form things called “radicals,” which are molecules with an odd number of electrons (“unpaired electrons”). Usually, atoms have even numbers of electrons (their goal is to have eight (or 4 “pairs”, whether they get them by stealing them from other molecules, or by nicely sharing them). Radicals are not stable. They really, really want to have an even number of electrons. They react with practically anything because of this. In the human body, free radicals form partly because of unavoidable cellular operations, and partly because of environmental toxins. During cellular respiration, which is how our cells convert nutrients to energy, the “superoxide” radical, O2-, can be formed. Totally normal and natural.

Superoxide, a radical molecule

On the other hand, free radicals can also be formed in less natural ways, such as through cigarette smoke. Chemicals in cigarettes, such as those in tar, react with oxygen as they are inhaled, and create radicals. Substances that create free radicals are one type of carcinogen.

carrots

See how the third molecule has only seven electrons?

Too many free radicals is not a good thing. Because they are so reactive, they end up interfering with really important things, like DNA. In cell, a radical might grab a hydrogen off a nearby molecule in the cell as it looks to be more stable. But then, that nearby molecule becomes a radical, looking to steal an electron from something else. It’s like dominos, except the dominos are pieces of your cells, and if enough of them fall over, you have a dead cell. Some scientists believe this is why aging occurs. Or, sometimes you have a cell whose DNA is now damaged, but can still replicate. That’s cancer. Not good.

This is a diagram of the radical reaction, where the O’s represent oxygen atoms, the H’s represent Hydrogen atoms, and the R’s represent groups of atoms with Carbons in them. If you follow the little black dot (that’s the extra electron that makes a radical), you can see that the chain reaction starts all over again when you get to the bottom.

Luckily for our cells, there are antioxidants! And better yet, there’s a fun and easy way to get antioxidants into your body. Eating food! Well, not any food. Many fruits and vegetables (and some nuts) have been found to contain high amounts of anti-oxidants. Some of the most famous ones include Vitamins C and E and beta-carotene. Plus, the body makes a few of its own enzymes that collect free radicals.

So, what exactly are “anti-oxidants,” and what’s so awesome about them that they can potentially help prevent cancer? Anti-oxidants are molecules or enzymes that grab the odd electron from radicals, and neutralize the radical, so they become harmless. These molecules either have an extra electron themselves, or react in such a way that the radical is broken down into a stable molecule. The other way in which anti-oxidants work is by making mitochondria more efficient. Mitochondria are tiny bean-shaped organs inside every cell that play a major part in cellular respiration (making energy). Since they’re so vital to this process, they’re often exposed directly to the free radicals that are made. Poor little mitochondria. The more anti-oxidant rich foods you eat, the more efficiently the mitochondria can produce energy (so, more energy, less radicals). Anti-oxidant rich foods are like force fields for the parts of your cells. Here is a list of some of the most anti-oxidant rich foods.

 

Keep reading, and keep eating your greens : )

Leave comments if you have questions- I’ll do my best to answer!

-Ashley

 

Sources:

http://www.rice.edu/~jenky/sports/antiox.html

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/ROS.html

http://www.sciencelearn.org.nz/Contexts/Digestion-Chemistry/Looking-Closer/Mitochondria-cell-powerhouses

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1568603/

http://www.rps.psu.edu/probing/antioxidants.html