Molcular model of insulin molecule, ribbon.

Molecular model of the insulin molecule. Each dimer is shown in a different colour. Insulin molecules consist of two polypeptide chains (A and B) linked by disulphide bonds. Insulin decreases blood glucose concentrations, and increases cell permeability to monosaccharides, amino acids and fatty acids. Defects of insulin are the causeof hyperinsulinemia and type-II diabetes mellitus.