A second messenger is
A) a substance that brings about a desired effect in a cell as a result of a hormone binding to its receptor on the cell surface
B) a hormone that acts on a target cell, not one of the releasing factors or trophic hormones that act on specific endocrine glands
C) a hormone that affects the DNA of the target cell
D) a specialized form of mRNA

Question

Quizplus · Accepted Answer

Second messengers are substances that are released inside a cell in response to the binding of a hormone (or another signal molecule) to a receptor on the cell's surface. They help amplify and propagate the signal within the cell to elicit a response.

A Second Messenger Is