Creatine is made up of all, except -

Ans. is 'b' i.e., Alanine o Creatine and creatinine are not amino acids, but specialized products of amino acids. Creatine is synthesized from glycine, arginine and methionine. Synthesis start with formation of guanidoacetate from glycine and arginine in kidney. Further reactions takes place in liver and muscle.Thus, both creatine and creatinine are synthesized from arginine, glycine, and methionine.