Question

Excess ATP inhibits respiration by inhibiting one of the following enzymes

• A. Phosphofructokinase
• B. Hexokinase
• C. Pyruvic decarboxylase
• D. Aldolase

Answer 1

The correct option is A Phosphofructokinase

Allosteric inhibition is caused by the inhibitor which attaches at the site other than active site and brings a conformational change in the enzyme which prevents the formation of enzyme substrate complex. Phosphofructokinase helps in the phosphorylation of fructose- 6- phosphate to fructose 1,6 biphosphate. High levels of ATP allosterically inhibits the enzyme phosphofructokinase.

So, the correct answer is option A.