Chapter 22, Problem 18RE

Interpretation Introduction

Interpretation:

The reason for stating the standard reduction potential for the photosynthetic reaction is to be determined.

Concept introduction:

The standard reduction potential is defined as the measure of the individual electrode potential for a particular reversible electrode at standard state, having the ions with the effective concentration of one mol/L and a pressure of one atm.

Photosynthesis occurs in the presence of light, and water is converted to oxygen by oxidation and ${\text{NADP}}^{\text{+}}$ is reduced to $\text{NADPH}$.

${\text{NADP}}^{\text{+}}{\text{ + H}}_{\text{2}}\text{O }\to {\text{ NADPH + H}}^{\text{+}}\text{ + }\frac{1}{2}{\text{O}}_{\text{2}}$

$\text{NADH}$ is oxidized to ${\text{NAD}}^{\text{+}}$, while oxygen is reduced to water. The reaction is given as :

$\text{NADH + }\frac{1}{2}{\text{O}}_{\text{2}}{\text{ + H}}^{\text{+}}\to {\text{ NAD}}^{\text{+}}{\text{ + H}}_{\text{2}}\text{O }$