Question

Respiratory enzymes are activated by

• A. N and P
• B. Mg and Mn
• C. K and Ca
• D. S and Fe

Answer 1

The correct option is B Mg and Mn

Most of the respiratory enzymes use Mg, Mn and Fe ions as cofactors for their catalytic activities.

For example: The enzyme fructokinase uses Mg ions for conversion of fructose to fructose-6-phosphate. The enzyme aconitase requires Fe ions for catalysing the conversion of citrate to isocitrate in the TCA cycle. Mn ions help in the conversion of isocitrate to alpha-ketoglutarate with the help of the enzyme, isocitrate dehydrogenase.