Proteins

Proteins are the fundamental structural materials of animal bodies -- they build muscle, skin, hair, nails and connective tissue -- and, in the specialised form of enzymes, they also drive essentially every physiological (biochemical) reaction that keeps a living organism functioning. The name 'protein' itself reflects this central importance: it is derived from the Greek word 'proteios', meaning 'primary' or 'of prime importance'. Nutritionally, the major dietary sources of protein are milk, pulses (legumes), nuts, fish and meat. Chemically, proteins belong to the class of polyamides: they are high-molecular-weight polymers whose repeating monomer units are alpha-amino acids, joined to one another by amide (peptide) linkages -- …