Question

By convention, what is the beginning of a protein known as?

a) 5' end
b) 3' end
c) N-terminus
d) C-terminus

Answer 1

The beginning of a protein is known as the N-terminus, where the amino group of the chain is free.

Step-by-step explanation:

By convention, the beginning of a protein is known as the N-terminus. This is the end of the peptide or protein where the amino group is not involved in the formation of a peptide bond and is therefore free. When representing a protein on paper, the N-terminal amino acid is written first on the left side, and the C-terminus, which is the end with a free carboxyl group, is written at the end on the right side. The N-terminal amino acid is very important as it can determine the protein's location within the cell, when the signal sequence which is usually at the N-terminal end is attached.