Assertion (A) : Human diet should compulsorily contain Glycrine, Serine and Tyrosin. Reason (R) : Essential amino acids cannot be synthesised in the human body.

The assertion is incorrect. Glycine and serine are classified as nonessential (or conditionally essential) because the human body can synthesize them, and tyrosine is considered conditionally essential (synthesized from phenylalanine under normal conditions) rather than being one of the nine strictly essential amino acids that must be obtained from the diet [1]. The Reason statement is correct in definition: “essential amino acids” are those that humans cannot synthesize and therefore must obtain from food [1]. Texts specifically list glycine, serine, and tyrosine among amino acids that are nonessential or conditionally essential, so they are not universally required “compulsorily” in the diet for healthy adults in the way true essential amino acids are [2].

Sources

1. [1] https://www.sciencedirect.com/topics/medicine-and-dentistry/essential-amino-acid
2. [2] https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/essential-amino-acid