Question

10 back to review which of the following steps in a signaling pathway typically occurs first once a chemical messenger reaches a target cell? a specific genes are activated. b a second messenger molecule is produced. c a ligand binds to a receptor. d specific proteins are synthesized.

Explanation:

Cell signaling pathways start when an extracellular chemical messenger (ligand) first interacts with a target cell by binding to its specific receptor on the cell surface or inside the cell. All other listed steps (activating genes, producing second messengers, synthesizing proteins) occur after this initial binding event.

Answer:

C. A ligand binds to a receptor