BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Since each of the 20 amino acids is chemically distinct and each can, in principle, occur at any position in a protein chain, there are 20 × 20 × 20 × 20 = 160, 000 different possible polypeptide chains four amino acids long, or 20n different possible polypeptide chains n amino acids long.

Detailed explanation-2: -The essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The nonessential amino acids are alanine, asparagine, aspartic acid, glutamic acid, and serine.

Detailed explanation-3: -One hundred or more amino acids are linked together with covalent peptide bonds in various specific sequences in the polypeptide chain with polypeptide chains combining to form a protein. Every protein has at least one stable three-dimensional configuration.

Detailed explanation-4: -Peptides are formed by combining the 20 amino acids in different combinations and sequences.

Detailed explanation-5: -The difference in the side-chain group or R-group is what determines the unique properties of each amino acid.