What is the significance of the N-terminal and C-terminal ends in a protein?

• A. They indicate the directionality of the protein, with the N-terminal having a free amino group and the C-terminal having a free carboxyl group.
• B. They are involved in the protein's ability to bind to DNA.
• C. They determine the protein's solubility in water.
• D. They are responsible for the protein's enzymatic activity.

Answer: (A)