This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
[{'content': 'Which of the following is true about glycine? \nSelect and explain. \nA. Glycine is an essential amino acid, B. Sulphur containing at 4th position, C. Has a guanidine group, D. Optically inactive', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans: d (Optically inactive) Ref: Vasudevan, 4th, ed, p. 5th ed, p. 173Glycine is the simplest amino acid.Optically inactive.It forms every third amino acid in collagen (and most abundant amino acid in collagen).Glycine is a glucogenic amino acid formed from serine.Guanido group is present in arginine.ESSENTIAL AMINO ACIDNON ESSENTIAL AMINO ACIDLeucineValine,AlanineGlutamic acidLysineThreonine,GlycineAspartic acidIsoleucineTiyptophan,ProlineTyrosinePhenylalanineMethionineCysteineSerineAsparagineGlutamineSEMI ESSENTIAL AMINO ACIDS:Arginine, histidine.', 'role': 'assistant'}]