Which of the Following is True During a Typical CAMP-Type

Question

Which of the following is true during a typical cAMP-type signal transduction event?
A)The second messenger is the last part of the system to be activated.
B)The 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.
E)cAMP is waiting in the cell ready for the signal to be transduced.

Accepted Answer

During a typical cAMP-type signal transduction event, the hormone binds to a receptor on the cell surface, which activates the G protein. The G protein then activates adenylyl cyclase, leading to the production of cAMP, which acts as a second messenger. The cAMP then activates protein kinase A (PKA), which phosphorylates target proteins in the cell, leading to the cellular response. Therefore, adenylyl cyclase is activated after the hormone binds to the cell and before phosphorylation of proteins occurs.