Try 5 free practice questions with instant feedback. See how ready you are.
Question 1
What are the three sequential stages of cell signaling described in AP Biology?
Answer: Reception, transduction, and response. In reception, a signaling molecule binds a receptor; in transduction, the signal is converted and relayed; in response, a specific cellular activity is triggered.
Question 2
During which stage of cell signaling does a phosphorylation cascade typically occur?
Answer: Transduction. Phosphorylation cascades relay and amplify the signal by sequentially activating proteins through the addition of phosphate groups.
Question 3
How does signal amplification occur during the transduction stage?
Answer: Each activated relay molecule can activate many downstream molecules, so a small number of signaling molecules can trigger a large cellular response.
Question 4
Where are G protein-coupled receptors (GPCRs) located in the cell, and what is their general structure?
Answer: GPCRs are transmembrane receptors located in the plasma membrane. They consist of a single polypeptide that passes through the membrane seven times.
Question 5
What happens to a G protein when a ligand binds to a GPCR?
Answer: The activated GPCR causes the G protein to exchange GDP for GTP, activating the G protein, which then dissociates and activates an effector enzyme such as adenylyl cyclase.