Question

Arrange the following steps in the action of water soluble hormone upon a target cell in the correct sequence:

1) Adenylate cyclase converts ATP to cAMP
2) Hormone binds to receptor site on cell membrane (first messenger)
3) cAMP serves as second messenger to activate protein kinase
4) Protein kinase is activated to cause the specific effect mediated by the hormone
5) G-protein is activated

a. 1, 2, 4, 5, 3
b. 2, 5, 1, 3, 4
c. 2, 1, 5, 4, 3
d. 5, 1, 3, 4, 2

Answer 1

The correct sequence for the action of water-soluble hormones on a target cell is hormone binding to membrane receptor, G-protein activation, adenylate cyclase conversion of ATP to cAMP, cAMP acting as a second messenger, followed by the activation of protein kinase.Therefore, the correct sequence would be: b. 2, 5, 1, 3, 4.

Step-by-step explanation:

To arrange the steps in the action of water-soluble hormones upon a target cell in the correct sequence, one must follow the actual biological process through which hormones exert their effects. Here is the order:

1. Hormone binds to receptor site on cell membrane (first messenger)
2. G-protein is activated
3. Adenylate cyclase converts ATP to cAMP
4. cAMP serves as second messenger to activate protein kinase
5. Protein kinase is activated to cause the specific effect mediated by the hormone

Therefore, the correct sequence would be: b. 2, 5, 1, 3, 4.