Week 10 – Types of Calories – Protein

Proteins are the “sexy” calorie source and they have a huge responsibility in the body. They are the building blocks of muscles and perform important functions at the cellular level as enzymes breaking down chemicals into other chemicals. Proteins are essential for bodily functions such as metabolism, hormone production and utilization, memory, and movement. Protein’s primary function is not to provide the body with energy but it can serve that purpose if no other energy source is present. Just like saccharides are combined into long chains to form complex carbohydrates, amino acids are combined into long chains to form proteins.

Amino Acids

Hopefully now you realize that amino acid molecules make up proteins and proteins make up muscles in your body. There are many different amino acids but only 20 of them are needed to compose muscle. Of these 20 amino acids, 8 of them are considered essential amino acids. These 8 amino acids are very important because your body cannot synthesize them by itself and must obtain them in their original form from your diet. This concept is especially important to understand if you are attempting to build muscle on a vegan or vegetarian diet because it can be quite difficult to get the correct combinations of the 8 essential acids without eating meat. As mentioned earlier the other 12 amino acids still need to be in your diet to build muscles, but if you have too much of one, your body can convert it into a different one that it doesn’t have enough of.

The chemical formula of an amino acid is H2NCHRCOOH
Amino Acid

Notice that the structure is similar to a simple carbohydrate in that is contains carbon, oxygen, and hydrogen in the same ratio. The difference is that it has a nitrogen atom and an R. The Nitrogen atom can become a problem for people with too much protein in their diet because when protein is broken down for energy, or converted into fat, the nitrogen becomes free and has to be filtered out by your body. Excess free nitrogen in your body is toxic and your body must work particularly hard to remove them. This problem will be discussed greater in future blog entries.

If you’ve taken chemistry in high school you might realize that R is not symbol in the periodic chart of elements. Your observation is correct. R does not represent an atom but actually represents a group of atoms known as the R-Group. Every amino acid has the H2NCHCOOH atoms arranged in exactly the same way, the only thing that differentiates amino acids is the group of atoms at the R position. All 20 different amino acids found in proteins have a different R-Group which makes it act differently in the body and perform different functions.

The chemical formula for Tryptophan(shown below) is: C11H11N2O2

Tryptophan

One famous amino acid is the one shown above…Tryptophan is commonly blamed making people tired after a huge Thanksgiving Day turkey dinner. Tryptophan is an essential amino acid thus it is found in all meats so next time you’re tired after Thanksgiving dinner it’s probably not becuase of the turkey but rather that you ate too much turkey! Notice that the Tryptophan molecule has a Carbon atom, a Hydrogen atom, a Carboxyl Group(CO2H), an Amino Group(NH2), and an R-Group just like all other amino acids. Tryptophan’s R-Group happens to have a unique chemical formula of C9H8N. Your body puts together Tryptophan and the other 19 amino acids in different combinations to make proteins which build and maintain muscle tissue. Muscle mass is an important part of the weight equation because it has a very significant impact on your basal metabolic rate, which will be discussed in a later blog entry.

Here is a 3-Dimensional example of a protein(the enzyme Hexokinase) containing many different amino acids connected in many different ways. Like all proteins, this extremely unique protein serves an extremely unique purpose in the body.

Hexokinase_Enzyme

Common foods with high amounts of protein are:

Poultry
Pork
Beef
Fish

The most important thing to know about protein when applying The Weight Equation is:

1 gram of protein contains 4 calories

References:

http://www.mckinley.illinois.edu/handouts/macronutrients.htm
http://www.proteinstructures.com/Structure/Structure/amino-acids.html
http://www.britannica.com/science/amino-acid
http://www.chem.purdue.edu/gchelp/molecules/trp.html

Please enjoy the powerful information I am sharing in this blog but remember that I am NOT a nutritionist or a professional. I am simply passionate about the subject. Please consult with your doctor and nutritionist before implementing any diet.

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