Which of the Following is NOT a Common Second Messenger

Question

Which of the following is NOT a common second messenger in cell signaling?
A) Ca²⁺
B) Cyclic adenosine monophosphate
C) Diacylglycerol
D) Tyrosine
E) Inositol trisphosphate

Accepted Answer

Second messengers are small chemicals generated in large amounts in response to receptor activation in signaling pathways and diffuse away from their source to spread the signal. Some are water-soluble [e.g. calcium ions and cyclic adenosine monophosphate (cAMP)] and some are lipid-soluble [e.g. diacylglycerol (DAG) and inositol trisphosphate (IP₃)].