Question

The correct structure of the tripeptide Glycine -- Alanine -- Glycine is

• A. Structure 1
• B. Structure 2
• C. Structure 3
• D. Structure 4

Hint:

While writing peptide structures, the amino acids are written from the \[ \boxed{\text{N-terminal} \rightarrow \text{C-terminal}.} \] Thus, \[ \boxed{ \text{Gly--Ala--Gly} = \mathrm{H_2NCH_2CONHCH(CH_3)CONHCH_2COOH}. } \]

Answer 1

The Correct Option is B

Step 1: Recall the structures of the amino acids. Glycine: \[ \boxed{\mathrm{H_2NCH_2COOH}} \] Alanine: \[ \boxed{\mathrm{H_2NCH(CH_3)COOH}} \]

Step 2: Form the tripeptide. The sequence Glycine--Alanine--Glycine gives \[ \boxed{ \mathrm{H_2NCH_2CONHCH(CH_3)CONHCH_2COOH}. } \] This corresponds to Structure 2.

Step 3: Choose the correct option. Hence, the correct option is \[ \boxed{(B).} \]