There are 24 different peptide configurations possible for a tetrapeptide composed of four different amino acids.
Explanation:
A peptide is formed by linking amino acids together. The number of different possible peptide sequences depends on the number of amino acids in the peptide and the number of different amino acids available.
For a tetrapeptide (a peptide with four amino acids), if we assume that we have four different amino acids (let's call them A, B, C, and D), then the number of possible sequences is calculated as follows:
- For the first amino acid position in the tetrapeptide, we have 4 choices (A, B, C, or D).
- For the second position, we have 3 remaining choices (since we've already used one amino acid).
- For the third position, we have 2 remaining choices.
- For the fourth position, we have only 1 remaining choice.
Therefore, the total number of possible tetrapeptide sequences is 4 3 2 * 1, which is 4! (4 factorial).
4! = 4 3 2 * 1 = 24
This means that there are 24 different ways to arrange four different amino acids into a tetrapeptide.
Example:
If our amino acids are Alanine (A), Glycine (G), Cysteine (C), and Valine (V), some of the possible tetrapeptides are:
- AGCV
- AGVC
- ACGV
- ACVG
- AVGC
- AVCG
- GACV
- GAVC
- GCVA
- GCAV
- GVAC
- GVCA
- etc. up to 24 total combinations.
Important Note: This calculation assumes that all four amino acids are different. If there are repeats of the same amino acid, the number of unique configurations decreases. For instance, a sequence like AAAA would only count as one configuration, not 24.
