Why are amino acids important?
Amino acids (AA) are organic compounds that combine to form proteins. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, although other elements are found in the side chains of certain AAs. Proteins and amino acids are the building blocks of life.
When proteins are digested or broken down, Amino Acids are left. The human body uses AAs to make proteins to help the body:
- Break down food
- Grow
- Repair body tissue
- Perform many other body functions
The primary functions of proteins are to build our muscles, bones, hair, and nails, but that is only the start. Amino acids make up the enzymes that facilitate the myriad chemical reactions in our bodies. They carry nutrients and other necessary molecules through our blood and across cell membranes. They carry signals from one part of the body to another. The antibodies which protect us from illness are also proteins. The tasks of proteins are just too many to count. AAs can also be used as a source of energy by the body.
What are the main types of amino acids?
There are totally 23 proteinogenic (protein building) amino acids, and over 100 natural amino acids, which are non-proteinogenic. Of the proteinogenic AAs, 9 are essential, 11 which are nonessential, and 3 of which are not found in the human body.
Essential Amino Acids
- Essential amino acids cannot be made by the body. As a result, they must come from food.
- The 9 essentials are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
- Out of the nine essential amino acids, three are the branched-chain amino acids (BCAAs): leucine, isoleucine and valine.
- “Branched-chain” refers to the chemical structure of BCAAs, which are found in protein-rich foods such as eggs, meat and dairy products. BCAA supplements have been shown to build muscle, decrease muscle fatigue and alleviate muscle soreness.
- Studies report that total BCAA intakes between 15–35 grams per day seem generally safe
Nonessential Amino Acids
- Nonessential means that our bodies produce an amino acid, even if we do not get it from the food we eat.
- They include: alanine, arginine, asparagine, aspartate, cysteine, glutamine, glycine, ornithine, proline, serine and tyrosine
- Out of the 11 non essentials, 8 of them are so called “conditional”, i.e., are usually not essential, except in times of illness and stress. They are: arginine, cysteine, glutamine, tyrosine, glycine, ornithine, proline, and serine.
- A naturally-occurring chemical compound, carnitine or L-carnitine, is technically speaking, not an amino acid. It is actually a dipeptide made from the essential amino acids lysine and methionine. It is therefore often classed as a conditionally essential AA.
Sources of Amino Acids
Whey protein is one of the few sources that naturally contain all 20 amino acids, making it a complete protein.
Amino acids are available as individual AAs or in AA combinations. They also come as part of multi-vitamins, proteins, and food supplements. Usually, you should take AA combinations instead of individuals. Using a single amino acid supplement may lead to negative nitrogen balance. This can decrease how efficient your metabolism is. It can also make your kidneys work harder.
To further learn about proteins for academic purpose, you can visit the Protein Database of NCBI (National Center for Biotechnology Center).
