A protein is a polyamide or polypeptide, a polymer built from amino acid monomers. The great majority of proteins are made from various combinations of the 20 different and naturally occurring Amino acids. Molecules of amino acid share a common structure. For chemical species are attached to the Carbon Atom: a carboxylic acid group, a amine group, a hydrogen group, and a sidechain designated R, all shown in figure 11.16. Variations in R sidechain differentiate individual amino acids, as shown in figure 11.17. For example in the simplest amino acid, R is a hydrogen atom. Two amino acids can come by and buy a condensation reaction between the amine group on one amino acid and a carboxylic acid group on the other. Note that the acidotic -COOH Group of the glycine molecule reacts with the -NH2 Group of Alanine molecule. In the process, that you amino acids laying through the C-N peptide bond shown in the blue shaded area. Equation 11.4 A labels the product as dipeptide, a compound formed from two amino acids. Look closely to see the two dipeptides are different. The point of all this is that the order of amino acid residues in a peptide makes a difference. The particular protein forms depends not only on which amino acid are present, but also their sequence in the protein chain. Assembling the correct amino acid sequence to make a particular protein is like putting letters in a word; if they are in a different order, a completely new meaning results. Thus, a tripeptide consisting of three different amino acids is like a three letter word containing the three letters a, e, and t. normally, the body does not store at a reserve supply of protein, so foods contains must be in regularly. Coming children, pregnant women, and persons recovering from long-term debilitating illnesses or Burns of the positive nitrogen balance, this means that they consume more nitrogen than they excrete because they’re using the element to synthesize additional protein. A negative nitrogen balance exists when more protein is being decompose then being made. Another case of Meganite imbalance maybe a diet that does not include enough of the essential amino acids, those required for proteins synthesis but that and must be obtained from the diet because the human body cannot synthesize them. Good nutrition thus requires in insufficient quantity and suitable Quality. However, most people of the world Italian greens and other vegetable crops rather than on meats or fish. For example, Mexican and Latin American diets tend to be rich and corn or corn products, a protein source that is incomplete because corn is low tryptophan, and essential amino acid. Fortunately for millions of vegetarians, a resilience on vegetable protein does not do them for malnutrition. The trick is to apply the principal nutritionist call protein complementarity, combining food that complement essential amino acid content so that the total diet provides a complete supply of amino acids for protein synthesis. The traditional diets in many countries also tend to meet protein requirements. People in middle east combined Bulger wheat with chicken peas or human hummus a paste made from sesame seeds.