All are essential amino acids except -

Ans. is 'b' i.e., Arginine Arginine is semi-essential AA. o Among these arginine is a semi-essential amino acid which can by synthesized partially in the body. Other three are absolute essential amino acids and cannot be synthesized in the body o On the basis of nutritional requirement, amino acids are classified into two groups: - A) Essential amino acids:- # These cannot be synthesized by the body and therefore should be supplied in diet. # There are ten essential amino acids Phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, arginine, lysine, leucine, (Mnemonics PVT. TIM. HALL). # Among the ten essential amino acids, two amino acids are semiessentials, arginine and histidine, because they are synthesized partially in human body. # As essential amino acids cannot be synthesized in body, their deficiency in diet produces negative nitrogen balance. B) Nonessential amino acids:- # These can be synthesized in human body. Remaining 10 amino acids are nonessential amino acids. # These are: alanine, aspartic acid, aspargine, cysteine, glutamine, glutamic acid, glycine, proline, serine, and tyrosine.