Given the energy charge equation below, if a biological system has an EC = 0.8, what is true about the concentrations of ATP, ADP, and AMP in the system?
A) The concentrations are all equal.
B) There is more ADP in the system than ATP or AMP.
C) There is more ATP in the system than ADP or AMP.
D) There is more AMP in the system than ATP and ADP.

Question

Given the energy charge equation below, if a biological system has an EC = 0.8, what is true about the concentrations of ATP, ADP, and AMP in the system? 
A) The concentrations are all equal. 
B) There is more ADP in the system than ATP or AMP. 
C) There is more ATP in the system than ADP or AMP. 
D) There is more AMP in the system than ATP and ADP.

Quizplus · Accepted Answer

The energy charge equation is EC = ([ATP] + 0.5[ADP])/([ATP] + [ADP] + [AMP]). If the EC = 0.8, then ([ATP] + 0.5[ADP])/([ATP] + [ADP] + [AMP]) = 0.8. Rearranging this equation gives 0.2[ATP] = 0.3[ADP] + 0.5[AMP]. Since the concentrations of ATP, ADP, and AMP must add up to 1, we can substitute 1 - [ATP] for [ADP] + [AMP], giving 0.2[ATP] = 0.3(1 - [ATP]) + 0.5(1 - [ATP]). Simplifying this equation gives [ATP] = 0.67, [ADP] = 0.24, and [AMP] = 0.09. Therefore, there is more ATP in the system than ADP or AMP.

Given the Energy Charge Equation Below, If a Biological System