What is Protein? Good Sources of Protein
Protein is composed of nitrogen containing compounds called amino acids. These amino acids will bond to each other to form what biochemists call peptide polymers, which in turn will form particular proteins. The sequence of amino acids in the peptide polymer will determine the nature of the protein, and there are many different kinds of proteins.

Protein is composed of nitrogen containing compounds called amino acids. These amino acids will bond to each other to form what biochemists call peptide polymers, which in turn will form particular proteins. The sequence of amino acids in the peptide polymer will determine the nature of the protein, and there are many different kinds of proteins.
Proteins may be used to form new bodily tissue, e.g.muscle, bone, teeth, skin, and nervous tissue, as well as enzymes and globulins necessary for maintaining life.There are twenty two amino acids, eight of which are termed essential amino acids, meaning that these eight have to be supplied by the diet. The other amino acids may be synthesized by the body from other nonessential amino acids.
Foods containing all eight of these essential amino acids are termed complete proteins. Those lacking one or more of the essential aminos are termed incomplete proteins. The relative proportion of amino acids compared to those found in human tissue, as well as the degree of assimilability will determine the biological value and protein efficiency ratio of a particular protein. For example, while both soybeans and milk contain complete proteins, milk proteins such as whey, casein, and lactalbumin will have a higher biological value. Gelatin, for example, while classified as a protein, lacks the essential amino acid tryptophan, thereby making gelatin useless as a protein unless enough tryptophan is supplied to make it assimilable. Rated according to their biological value are the following:- Egg
- Milk
- Meat
- Fish
- Soy
- Peanut
- Wheat gluten