The number of tri peptides formed by three different amino acids are?

6

The correct answer is option 4. 6.

To determine the number of possible tripeptides that can be formed from three different amino acids, we need to consider the permutations of these amino acids in a tripeptide sequence.

For a tripeptide, each sequence is a combination of three different amino acids arranged in a specific order. The formula for the number of permutations of \( n \) distinct items taken \( r \) at a time is given by \( n! / (n - r)! \), where \( n \) is the total number of items and \( r \) is the number of items to arrange.

In this case:

We have 3 different amino acids.

We want to arrange all 3 of them (so \( r = 3 \)).

The formula simplifies to \( n! \):

\(\text{Number of permutations} = 3! = 6\)

Each arrangement of the three amino acids represents a different tripeptide.

\(3! = 3 \times 2 \times 1 = 6\)

The number of tripeptides that can be formed by three different amino acids is \( \textbf{6} \).