FUNCTION OF AMINO ACIDS

1. Proteins are polymers of amino acids.
2. Glycine form porphyrin nucleus in chlorophyll and heme (= haem) proteins like haemoglobin and cytochromes.
3. Cysteine produces disulphide linkage among polypeptides.
4. Tyrosine form skin pigment melanin and two hormones thyroxine (= thyroxin) and adrenaline.
5. Histamine is formed during allergic inflammatory reactions. It causes dilatation of capillaries, decreases blood pressure, constricts smooth muscles (e.g., bronchi, uterus) and increases gastric secretions.
6. Peptidolycans are structural units of prokaryotic cell wall.
7. Glutathione is a coenzyme of oxidation-reduction reactions which consist of a tripeptide of lutamic acid, Cysterine and Glycine. The chemical is important in preventing oxidative damage to erythrocytes.
8. Bradykinin is a powerful arteriolar dilatators and brings about increased capillary permeability.