Protein is not just important, it is essential. Every single cell in your body is made up of protein. For example, brain cells are 10 percent protein. Muscle and red blood cells have as much as 20 percent. Overall, protein is the second largest building material of the human body (preceded only by water) comprising approximately 15% by weight.
To keep your cells alive, you must regularly give them protein. Even though it is not a superb source of energy such as carbohydrates and fats, you need protein and specific amino acids to keep the body functioning.
But not all proteins are the same. Proteins are made of amino acids that are linked together in long chains. Some amino acids can be made in the body and others must be consumed through the diet. What differs one protein from another is their amino acid content. There are about 20 commonly known amino acids which mix up and twist together in many different ways making between 10,000 and 50,000 different kinds of protein in the body.
What Are Amino Acids
Protein in our food cannot directly be used by the body, so it must break the protein down into it’s smaller subunits known as Amino Acids. Proteins consist of chains of hundreds or thousands of amino acids joined with peptide bonds. When you consume protein in food, the bonds linking the amino acids together are broken by digestive juices and enzymes into isolated amino acids. Only after this process is complete, your cells inside the digestive tract can absorb the nutrients and make them usable for the body.
Think of it as a jigsaw puzzle – protein is the puzzle and amino acids are the pieces that make it. If one or more pieces are missing, you can’t see the beauty of the picture. Same thing with protein – unless all amino acids are supplied through the diet, your body cannot make up proteins that are imperative in optimal growth of new healthy cells.
The body can’t store amino acids and will break down its own protein sources, including healthy muscle and organ tissues to meet its need for amino acids. If you want to keep your brain, muscles, bones, joints, all internal organs, even blood and lymph performing their functions you should constantly provide amino acids from a well-balanced diet.
Out of 20 amino acids required for proper body functioning and optimal health, your body can make 8-10 in sufficient amounts from glucose and other proteins. These are called non-essential and include alanine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, proline, and serine.
The remaining amino acids have to be supplied through your diet as your body is not able to make them, hence the name “essential amino acids”. These are tryptophan, lysine, methionine, phenylalanine, threonine, valine, leucine, and isoleucine. Their function is to serve as nitrogen donors to make other amino acids and supply the most important structural material for the new cells to develop and replace the old ones.
Semi-essential amino acids are arginine and histidine as the need for these increases if they get depleted at times of stress. Usually adults can make enough of these to maintain normal balance, just like nonessential amino acids. But children, those injured, ill, and even elderly need additional amounts to support muscle tissue growth due to higher metabolic demands.
What Do Amino Acids Do
Besides building cells and repairing tissue, amino acids form proteins such as antibodies to combat invading bacteria and viruses, and hemoglobin to carry oxygen around the body. Proteins also have many other roles including nucleoproteins that replicate your DNA for cell growth, make enzymes that perform numerous functions throughout the body, and even proteins that help produce more proteins!
It’s not the quantity of protein you take, but the quality and ratio of amino acids that keeps the body healthy and stable. The body can make 20,000+ proteins from essential amino acids, but it can only make as much as allowed by the least amino acid present in the body. For example, if one amino acid is only present at the 60% levelthe assimilation of all amino acids will be limited to that 60% level. This is called rate limiting and it makes balancing amino acid metabolism, using food protein, more difficult.
|Essential Amino Acids||Nonessential Amino Acids|
*May require increased amounts in times of bodily stress