Which of the following is true during a typical cAMP-mediated signal transduction event?
A) The second messenger is the last part of the system to be activated.
B) A hormone activates the second messenger by directly binding to it.
C) The second messenger amplifies the hormonal response by attracting more hormones to the cell being affected.
D) Adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation of proteins occurs.

Question

Quizplus · Accepted Answer

Adenylyl cyclase is activated after the hormone binds to the cell, but before phosphorylation of proteins occurs. This leads to the production of cyclic AMP (cAMP) which is the second messenger that amplifies the hormonal response by activating protein kinase A (PKA) and leading to the phosphorylation of target proteins. The hormone does not directly bind to the second messenger (cAMP) but instead activates the enzyme that produces it (adenylyl cyclase).

Which of the Following Is True During a Typical CAMP-Mediated