Proteins are biochemical compounds that are made up of one or more polypeptides typically wrapped in globular or fibrous form and perform certain biological functions. The polypeptides are composed of a linear polymer chain of amino acids linked by peptide bonds. They are essential dietary components and help our body rebuild muscle and bone tissue, to create new tissue, regulate hormones and control the metabolism, as well as, defend the body against various diseases.
Interesting fact: At least 10.000 different proteins make you and maintain you the way you are!
Many proteins function as enzymes that catalyze (speed up) biochemical reactions which makes them vital to the metabolism. They also have structural or mechanical functions. Such are the actin and myosin amino acids in muscles and the proteins in the cytoskeleton, which actually represents an armature which maintains cells in their form. Others are important in cell communication, in the immune responses and cell cycles.
The amino acids are the main building unit of proteins. There are 23 amino acids, 14 of which our body is able to produce, while the body is not capable to synthesize the remaining 9 due to lack of proper enzymes. With multiple mutual combining of these 23 amino acids, the body is able to synthesize diverse and numerous proteins that occupy and maintain many functions in living organisms.
Although there are numerous biochemical classifications taking into account the structure of amino acids, from the nutritional point of view, these amino acids can be divided into essential and non-essential amino acids, depending on whether the organism is, or is not capable of their synthesis.