Question

The number of tripeptides formed by three different amino acids using each amino acid once is ______.

Answer 1

Correct Answer: 6

Step-by-step Explanation
Consider three different amino acids, denoted as \( A_1 \), \( A_2 \), and \( A_3 \). A tripeptide is a linear sequence of three amino acids, where the order of the amino acids matters. To determine the total number of possible tripeptides, we need to find the number of permutations of the three amino acids.
Number of Permutations
The number of ways to arrange \( n \) distinct items is given by \( n! \). For \( n = 3 \) amino acids:
\[\text{Number of tripeptides} = 3! = 3 \times 2 \times 1 = 6\]
Conclusion
Six different tripeptides can be formed using three different amino acids, where each amino acid is used once.