Chapter 7, Problem 9MCQ

Summary Introduction

Introduction:

Superoxide ions (antioxidant) are the highly reactive, metabolic by-products of oxygen. They cause oxidation of lipids present in the cell membrane, causing damage to the cells (as they produce free radicals). For protection against superoxide ions, the cells of anaerobes release enzymes that nullify this chemical. These enzymes convert the superoxide ion to oxygen in two steps:

Step.1:

$2{\text{O}}_2{}^{-}+2{\text{H}}^{+}\stackrel{\begin{array}{l}\sup eroxide\\ dismutase\end{array}}{\to }{\text{H}}_{\text{2}}{\text{O}}_{\text{2}}+{\text{O}}_{\text{2}}$

Step.2:

$2{\text{H}}_{\text{2}}{\text{O}}_{\text{2}}\stackrel{catalase}{\to }2{\text{H}}_{\text{2}}\text{O}+{\text{O}}_2$