AP BIOLOGY

Detailed explanation-1: -A signal is detected when the chemical signal (also known as a ligand) binds to a receptor protein on the surface of the cell or inside the cell. 2. Transduction: When the signaling molecule binds the receptor it changes the receptor protein in some way. This change initiates the process of transduction.

Detailed explanation-2: -When a ligand binds an ion channel receptor, a channel through the plasma membrane opens that allows specific ions to pass through. This process requires a specialized membrane-spanning region of the receptor.

Detailed explanation-3: -A ligand that can bind to and alter the function of the receptor that triggers a physiological response is called a receptor agonist. Ligands that bind to a receptor but fail to activate the physiological response are receptor antagonists.

Detailed explanation-4: -What is the response of a receptor to the binding of a ligand to it at the cell’s extracellular surface? Option A: The receptor relays a signal across the membrane to the receptor’s cytoplasmic domain at the inner membrane surface.

Detailed explanation-5: -When a ligand binds to a protein, it undergoes a conformational change which in turn leads to a physiological response. The time a ligand spends attached to a receptor or specific protein is a function of the affinity between the ligand and the protein.