Final answer:
Amplification of a signal occurs at each of the described steps in the G-protein coupled receptor signaling pathway, where a single extracellular signal leads to the activation of multiple downstream molecules, resulting in a cascade that amplifies the original signal.
Step-by-step explanation:
Yes, amplification of a signal can occur at the particular steps described below:
- A. An extracellular signaling molecule binds and activates a GPCR: Yes
- B. The activated GPCRs cause Gα to separate from Gβ and Gγ: Yes
- C. Adenylyl cyclase produces cyclic AMP: Yes
- D. CAMP activates protein kinase A: Yes
- E. Protein kinase A phosphorylates target proteins: Yes
Each of these steps represents a point in the cellular signaling pathway where a single signal can lead to multiple downstream effects, thus amplifying the original signal. This is a characteristic of the G-protein coupled receptor (GPCR) signaling cascade, where the activation of one receptor can ultimately result in the activation of many molecules of protein kinase A, which then phosphorylate numerous target proteins, leading to a broad cellular response.