What is the N-terminal for the pentapeptide Val-Ile-Glu-Arg-Tyr?
A)The NH₃+ group on the side chain of Arg.
B)Valine.
C)Tyrosine.
D)Tryptophan.

Question

Quizplus · Accepted Answer

The N-terminal refers to the amino acid residue at the beginning of a peptide or protein chain. In this case, Valine is the first amino acid in the pentapeptide sequence and therefore the N-terminal. The NH₃+ group on the side chain of Arg is not part of the N-terminal, but rather a functional group on one of the amino acids within the sequence. Tyrosine and Tryptophan are not part of the sequence at all.

What Is the N-Terminal for the Pentapeptide Val-Ile-Glu-Arg-Tyr