<prompt> Which amino acid spares the use of methionine -CysteineGlycineHistidineArginine  <response>: Ans. is a i.e., Cysteine Adequate dietary source of cysteine spares methionine.o Methionine is an essential amino acid.o Methionine is required for synthesis of cysteine thus cysteine is non-essential amino acido Thus, cysteine can spare the requirment of methionine in diet. 