In the protein, Val-Tyr-His-Pro, which amino acid contains the N-terminal group?
1) histidine
2) proline
3) valine
4) tyrosine
To determine which amino acid contains the N-terminal group in the given protein sequence (Val-Tyr-His-Pro), we need to understand what the N-terminal group represents. The N-terminal group refers to the amino acid that is present at the beginning, or the N-terminus, of a protein or peptide chain.
To find the N-terminus in a protein sequence, we look for the amino acid that does not have any other amino acids attached to its N-terminus.
In this case, the N-terminal group is the amino acid at the very beginning of the sequence, which is Valine (Val). Therefore, the correct answer is:
3) Valine