Final answer:
The leader sequence of a protein, known as a signal sequence, determines the destination of the protein within the cell.
Step-by-step explanation:
The leader sequence of a protein that has just been translated functions to determine the destination of the protein. This leader sequence, often referred to as a signal sequence, is like a protein's "train ticket" to its ultimate destination inside the cell.
These sequences are recognized by signal-recognition proteins, which effectively act as conductors, directing the protein to its correct location, such as mitochondria or chloroplasts (in plants). Once the protein arrives at its intended cellular destination, the signal sequence is typically removed. Therefore, the correct answer to the student's question is B) determine the destination of the protein.