Question

Given below are two statements:
Statement I: Arginine and Tryptophan are essential amino acids.
Statement II: Glycine does not have any chiral carbon.
In the light of the above statements, which is the correct option?

• A. Both statement-I and statement-II are correct
• B. Both statement-I and statement-II are incorrect
• C. Statement-I is correct and statement-II is incorrect
• D. Statement-I is incorrect and statement-II is correct

Hint:

Remember that an amino acid is essential if the body cannot synthesize it and must obtain it from the diet. Also, glycine is the only amino acid without a chiral center.

Answer 1

The Correct Option is A

Let's evaluate each statement to determine the correct answer.

1. Statement I: Arginine and Tryptophan are essential amino acids.
   • An essential amino acid is one that cannot be synthesized by the human body and must be obtained from the diet.
   • Arginine is classified as a conditionally essential amino acid, meaning that it is typically synthesized by the body but may need to be obtained from the diet under certain circumstances, such as growth, illness, or injury.
   • Tryptophan is indeed an essential amino acid, as it must be acquired through dietary sources.
   • Based on this analysis, the statement is incorrect because Arginine is not strictly essential under normal conditions.
2. Statement II: Glycine does not have any chiral carbon.
   • A chiral carbon is one that is attached to four different atoms or groups.
   • The structure of glycine is \(NH_2CH_2COOH\), where the carbon atom in the middle is bonded to two identical hydrogen atoms.
   • Since the central carbon in glycine is bonded to two hydrogen atoms (not four different groups), it lacks a chiral center.
   • Therefore, statement II is correct.

In conclusion, Statement I is incorrect and Statement II is correct, making the option "Statement-I is incorrect and statement-II is correct" the correct choice.