Question

How many tripeptides can be prepared by linking the amino acids glycine, alanine and phenyl alanine?

• A. One
• B. Three
• C. Six
• D. Twelve

Hint:

If all amino acids are different, number of possible tripeptides = \(n!\) where \(n=3\).

Answer 1

The Correct Option is C

Step 1: Understand the concept.
A tripeptide consists of 3 amino acids linked in a sequence.
Different sequences give different peptides.
Step 2: Count permutations of 3 different amino acids.
Amino acids: Gly, Ala, Phe (all different).
Number of tripeptides possible:
\[ 3! = 6 \]
Step 3: List them (for clarity).
\[ Gly-Ala-Phe,\; Gly-Phe-Ala,\; Ala-Gly-Phe,\; Ala-Phe-Gly,\; Phe-Gly-Ala,\; Phe-Ala-Gly \]
Final Answer:
\[ \boxed{6} \]