Question
Biology Question on chemical coordination and integration
Which one of the following is not a second messenger in hormone action?
A
cGMP
B
Calcium
C
Sodium
D
cAMP
Answer
Sodium
Explanation
Solution
Sodium is not a second messenger in hormone action. Second messengers are typically small molecules or ions that transmit signals from the cell surface, where the hormone binds to its receptor, to the interior of the cell. cGMP (cyclic guanosine monophosphate), calcium ions (Ca2+), and cAMP (cyclic adenosine monophosphate) are all examples of second messengers involved in various cellular signaling pathways. Sodium is not typically considered a second messenger in hormone action.
So, the correct option is (C): Sodium