Tyler, How do low-carbohydrate diets work?

Over the last few years, the low-carbohydrate diet has become one of many common trends to help with weight lose. With all infomercials and friend’s friend’s miracle stories aside, are diets like the popular Atkins Diets really beneficial for our health? This diet works by cutting back on carbohydrates, which reduces the number of calories through out the day. With less calories, there is less fat that is stored in the body. During the introduction of the diet, the dieter loses what seems like an amazing amount of weight due to the low number of calories that are being transformed into storage (fat). In addition, the diet slows down after the first few weeks and it can cause bad breath, constipation, loss of energy as well as cancer or heart disease. If anyone is thinking about trying to loss some unneeded weight and go on a diet they should find out if they really are medically under- or over- weight. To figure this out, one should use a body mass index to calculate how fit they are. A person whose BMI lies between 25 and 30 is often classified as over weight and over 30 is obese.

BMI= To calculate your BMI, multiply your weight in pounds by 700, then divide the answer by the square of your height in inches.

Glycogen= functions as a short term energy for animal cells

South Beach Diet= Diet that was developed by Author Agatston and is based on eliminating “bad” carbohydrates

I have witnessed the low-carbohydrate diet fad first hand. When I was in high school my mother and cousin tried the popular Atkins diet. They both lost weight but after a few weeks it seemed as if the progress had stalled. This is expected due to the fact that the chapter article predicted this outcome. I personally think that it is a healthy diet to reduce the number of calories because they do lead to fat but to eliminate all carbohydrates seems too extreme.

Baird, Colin. Chemistry in Your Life. New York: H.W. Freeman and Company, 2006

Jennifer, Modern CSI

With the popularity of the TV drama, CSI produced my Jerry Bruckheimer; DNA testing has entered into the vocabulary of many court jurors. However, what the show fails to demonstrate is the amount of financing that is needed to undergo DNA testing and the time that it takes for the tests to be completed. The article describes the pros and cons to DNA testing and what a show like CSI or Perry Mason has done to transform the court system. Today, jurors demand DNA testing for almost every case, regardless of the other evidence already collected (including admission of guilt). This has attorneys angered, since more money and more evidence is needed to win a case. However, law officials are excited the DNA testing has received so much press. People are more likely to help fund new labs and buy more up to date equipment. Also, high school and college students are excited about the field, which increases the number of qualified lab techs and expert witnesses.

This article is great in that it gives both sides to the DNA forensic debate. It also shows how the court system has changed due to TV dramas. This would make for a great intro for my presentation.

Goehner, Amy. “Where CSI Meets Real Law and Order.” Time. 8 Nov. 2004.

Isaac, Beer basics

Most often created from barley, beer is a product of the fermentation process. The barley is soaked and left to sit for about a week, to malt, in order to build the enzymes necessary to convert the grain’s starch into sugar. By heating the grains to between 60 and 100 degrees Celsius, the grains are kept from sprouting during the germination process that develops the enzymes. Once the barley has been malted it is steeped in water and crushed in order to remove sediment and solid particles. The next step is to mash the starch product by heating it, allowing the enzymes to convert the starch to glucose and disaccharide maltose. In order to counter balance the sweet flavor caused by the residual carbohydrates the next step is to add hops, the bitter tasting flower blossoms that give beer its biting flavor. Again, the mixture is boiled and the hops are added to release the bitter flavor. The amount of hops added is based on the type of beer desired, for example, an ale requires no hops and a lager will require a generally small amount of hops. The fermentation process truly begins once yeast is added to the mixture. The live cultures react with the mixture to convert the maltose in the starches into carbon dioxide and ethanol that gives the beer is alcohol content. This process takes about one week to complete, during which several steps requiring different enzymes are required to boost the amount of alcohol created in the beer. After this process is completed, the mixture is strained again and then bottled and left to sit for several months to age and deepen in flavor and clarity.

Steeping: to soak in a liquid at a temperature under the boiling point (as for softening, bleaching, or extracting an essence)
Maltose: a crystalline dextrorotatory fermentable sugar C12H22O11 formed especially from starch by amylase

I think it is interesting to see how often the mixture has to be boiled in order to catalyze every reaction. Since the process takes up to several months to complete it also makes me wonder how old the commercial beer is that we drink, considering that aside from the fermentation and bottling process there is also time spent in shipping containers and on vendor shelves.

This article does not raise any serious concerns other than concerns regarding the age of consumed beer products, if that is even a factor worth considering. Perhaps newer, faster, or more efficient methods of brewing will come about in the near future.

Baird, Colin "Chemistry in Your Life" W.H Freeman and Company 2006, p291-293.

www.merriam-webster.com

Daisy, (sniff, sniff)

The matter we smell comes from evaporated liquid in its gaseous form. When we spritz some type of fragrance into the air and if we look closely enough we can see the liquid falling down, but what we actually smell are the molecules that have evaporated and gone into our nose and into our odorant receptors. These receptors come in many shapes and sizes and when we smell, its because the molecules have met the same characteristics and size of the receptor. While we have about 1000 different receptors dogs have many more than us, thus being far better at catching odors than us. Interestingly enough, these receptors are also connected to other parts of the brain which is why sometimes a certain smell can take us back to a time that we lived long ago-it has the power to make us recall old memories. Today, scientists are trying to understand the connection between a sexual partner and pheromones.

Pheromones: n. A chemical secreted by an animal, especially an insect, that influences the behavior or development of others of the same species, often functioning as an attractant of the opposite sex.

I thought it was really interesting that we are really sensitive to smell that is penetrable with water because our own receptors have a “thin layer” of water. Thus, gases that cannot penetrate water are not easily picked up by our noses.

The book states that scientists are working on artificial noses. These could potentially help distinguish other smells that are not so easily picked up by a human nose.

Baird, Colin, Chemistry in Your Life, 2nd Edition, pgs 43,44, Freeman, NY, 2006

"pheromone." The American Heritage® Dictionary of the English Language, Fourth Edition. Houghton Mifflin Company, 2004. Answers.com 18 Jan. 2008. http://www.answers.com/topic/pheromone

Kevin, Gold, not just a pretty metal

Gold was one of the first elements known to man. This is because it occurs in nature in the form of the solid metal and sometimes in very large pieces. Pure gold cannot be made in nature. The gold that is mined is an alloy that has other metals in it as well. The other metals can be taken out by a couple of different ways, including just melting down the mixture, or when it is in its liquid state blasting it with air, which turns the non-gold particles into a compound that is not soluble in metal, and can therefor just be taken off the top of the liquid gold. Gold is a very functional metal. Because, like all metals, its atoms can be reformed while still remaining close to each other, gold can be turned into wire or smashed out into sheets. The thin sheets of gold are used for decoration, both edible and non-edible, as well as for more practical purposes such as coating windows to either reflect or keep in heat. The gold used in jewelry is actually an alloy, mixed with silver, copper, and nickle. This is done because pure gold is very soft and mixing it with those other metals makes it strong enough to stand up to daily wear and tear. The amount of gold in an alloy is measured using carats. 24 carat gold is 100% pure gold. To get the carats of gold you divide the mass of gold in the sample by the mass of the whole sample and multiply that number by 24. (ex. (20/32) X 24= 15 carats)

Alloy-a mixture of metals
Compound-a material that consists of two or more types of atomsin a fixed ratio, with uniform composition throughout, and that connot be easily separated into its pure component elements.
Carat- gold-alloy classification system; carats of gold = 24 X fraction of mass that is pure gold

It was interesting to read on some of the more practical uses of gold. As far as I knew it was used almost purly for decoration. The bit about using it to coat windows was something completely new to me. It was also nice to learn exactly how the carat system works. Potentially lead to further investigation of the properties of gold and therefore potentially more uses for the element.

Baird, Colin "Chemistry in You Life" second edition. New York: W.H. Freeman and Company, 2006. 24-26, G-1, G-2, G-3

Jenna, Ages in history

The ages of history is discussed in chapter one, section eighteen of “Chemistry in Your Life”. Though this was an extremely short section, it was still very informational. This particular section talks about how people from the Stone Age began to make use of gold, silver, and copper that was found. Beginning with copper, it was actually one of the first metals ever used. People then began to notice certain characteristics about copper that allowed them to make and create objects of all sorts. After realization that objects could be made form copper, more and more became available to the people. During extraction, copper and tin ore accidentally got mixed together creating bronze. Bronze then became the “preferred material” due to the fact that it was easier to melt and shape. Thus, the Bronze Age began. The fabrication of metal requires liquid form. Iron was the next metal to be discovered, however, it does not become a liquid so it required a more advanced technological process to take place. This brought rise to the Iron Age.

Some words that I was not all that familiar with included: sickles, ores, optimum, and rudimentary.

Sickles: a short-handled implement with a curved blade used for cutting tall grass or grain.
Ores: rock mixtures of metal-containing compounds with other components.
Optimum: the best out of a number of several options or outcomes.
Rudimentary: existing at an elementary or basic level.

This particular section was, once again, extremely informative. It was actually quite interesting to learn about how the different ages in history came about. In all honesty, I have heard about these ages in history repeatedly throughout my years of school, but I never really knew how they came into existence or how they each got their particular names. That bit of information apparently got overlooked over and over again. It was also interesting to me how iron and bronze came to be through accidental discoveries and mishaps. This section in general was extremely interesting.

Baird, Colin. “Chemistry in Your Life”. Second Edition. W.H. Freeman and Company, New York. 2006. 23-24.

Boo, Good to raise public awareness about dangers of CO gas

Once I began having children, I found myself drawn to the “Women’s Magazines” at the supermarket check out. Interested in keeping my children safe I repeatedly noticed how over the last 20 years, the dangers of carbon monoxide poisoning have consistently made news in everything from Good Housekeeping to Woman’s World. Kits to check for carbon monoxide in your home are readily available at Home Depot and other retailers and awareness of carbon monoxide dangers have been the subject of everything from news broadcasts to Oprah. Why?

We all know that large amounts of carbon monoxide are fatal. (i.e. suicide by car parked in un-vented garage). What many people do not know is how severely carbon monoxide in low doses can degrade their health. Exposure higher than a few ppm can produce symptoms like headaches and drowsiness. Since theses symptoms are linked to many other causes, people often don’t suspect CO poisoning. CO inhibits the transfer of Oxygen molecules throughout the bloodstream. The CO molecules attach themselves to hemoglobin in the blood and limit the amount of hemoglobin available to attach to O2 molecules. This creates a condition where the heart must work harder to pump the available oxygen. If caught early, the CO can be displaced by forcing excessive amounts of O2 in to the bloodstream. Unfortunately the process of replacement takes time and as much as 30% of the 700,000 reported cases of CO poisoning in the U.S. each year result in some degree of brain damage. The CO inhaled by smokers and even non-smokers inhaling second hand smoke can lead to severe cardio vascular problems.

Hemoglobin: A hemoprotein composed of globin and heme that gives red blood cells their color; function primarily to transport oxygen from the lungs to the body tissues

Although the information in the text was not new to me, I was pleased to know that college students are learning about the dangers of CO poisoning so that they can be proactive in protecting their families now and in the future.

Baird, Colin, Chemistry in Your Life, 2nd Edition, pgs 90-91, Freeman, NY, 2006

WordNet 3.0, 2006 by Princeton University