This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Amino Acid Metabolism, Subject name: Biochemistry
[{'content': 'Tripeptide used for oxidation-raduction reaction - \nSelect and explain. \nA. Creatinine, B. Glutathione, C. Melanin, D. None', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Glutathione o Glutathione is a tripeptide0 made up of glutamate, cysteine and glycine (y-glutamyl-cysteiny 1-glycine).o Glutathione is present in all mammalian cells except neurons.o The sulphydryl (-SH) group of cysteine residue0 is the reactive portion of glutathione which can undergo oxidation and reduction.o Thus, glutathione may exist as the reduced (G-SH) or oxidized form (G-S-S-G) and can play a role in some oxidation- reduction reactions.o In oxidized form two molecules of glutathione are linked by disulfide bond.", 'role': 'assistant'}]