Which of the following substances activates protein kinases and thus acts as a second messenger?
A) insulin
B) ACTH
C) epinephrine
D) cyclic AMP
E) TSH
Answer: D
Which of the following substances activates protein kinases and thus acts as a second messenger?
A) insulin
B) ACTH
C) epinephrine
D) cyclic AMP
E) TSH
Answer: D