High School Biology : Transport and Signaling

Study concepts, example questions & explanations for High School Biology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #21 : Transport And Signaling

Which of the following is NOT an example of a second messenger?

Possible Answers:

IP3

Epinephrine (adrenaline)

cAMP

Ca2+

All of these are second messengers.

Correct answer:

Epinephrine (adrenaline)

Explanation:

Second messengers are intracellular signaling molecules. Epinephrine is a hormone that is released into the bloodstream and is thus never inside the cell. cAMP, Ca2+ and IP3 are all examples of second messengers. They respond to primary messengers—which are often hormones—by amplifying their effects and/or turning on downstream effectors.

Learning Tools by Varsity Tutors