Chapter 14, Problem 6P

Interpretation Introduction

Interpretation:

The minimum $\frac{{\text{NAD}}^{+}}{\text{NADH}}$ ratio in mitochondria needed to make the reaction exergonic at 37 ^oC should be calculated.

Concept Introduction:

For oxidation of succinate to fumarate in the presence of NAD⁺, the value of $\Delta G$ and $\Delta G^o$ is related to each other as follows:

  $\Delta G=\Delta G^o+RT\ln \frac{\left[\text{fumarate}\right]\left[\text{NADH}\right]}{\left[\text{succinate}\right]\left[{\text{NAD}}^{+}\right]}$

Here, $\Delta G$ is free energy change, $\Delta G^o$ is standard free energy change, R is universal gas constant, T is temperature, $\left[\text{fumarate}\right],\left[\text{succinate}\right],\left[\text{NADH}\right]$ and $\left[{\text{NAD}}^{+}\right]$ is concentration of fumarate, succinate, NADH and NAD+ respectively.