Creatinine is synthesized from -

Ans. is 'a' i.e., Arginine o Creatinine is synthesized from arginine, glycine and methionine.o Creatine and creatinine are not amino acids, but specialized products of amino acidso Creatine is synthesized from glycine, arginine and methionine.o Synthesis start with formation of guanidoacetatefrom glycine and arginine in kidney. Further reactions takes place in liver and muscle.o Imediate precursor of creatine is guanidinoacetate.o Thus, both creatine and creatinine are synthesized from arginine, glycine, and methionine.o In muscles, creatine phosphate occurs as a reservoir of high-energy phosphate groupso It provides a quick source of energy for muscle fibres to contract when they need an initial burst of energyo Creatine phosphate helps generation of ATP in exercising muscles by substrate level phosporylation.