Refer to the figure below, showing the enzyme cAMP-dependent phosphodiesterase converting cAMP to AMP.Chemical compounds that inhibit this enzyme are used as drugs to stimulate heart rate in patients with weak hearts. Which biological function does the nucleotide cAMP provide in this instance?
A) Agent of energy transfer
B) Signaling agent in muscle contraction
C) Carrier in the metabolism of carbohydrates and lipids
D) Energy storage molecule
E) Regulator of glucose metabolism

Question

Refer to the figure below, showing the enzyme cAMP-dependent phosphodiesterase converting cAMP to AMP.Chemical compounds that inhibit this enzyme are used as drugs to stimulate heart rate in patients with weak hearts.  Which biological function does the nucleotide cAMP provide in this instance?
A) Agent of energy transfer 
B) Signaling agent in muscle contraction 
C) Carrier in the metabolism of carbohydrates and lipids 
D) Energy storage molecule 
E) Regulator of glucose metabolism

Quizplus · Accepted Answer

The nucleotide cAMP acts as a signaling agent in muscle contraction, specifically in the stimulation of heart rate. Inhibition of the enzyme cAMP-dependent phosphodiesterase increases the amount of cAMP available for signaling, leading to increased heart rate.

Refer to the Figure Below, Showing the Enzyme CAMP-Dependent Phosphodiesterase