Question

For every, 1000 fold increase in pressure, the Km is _____________

(a) reduced to half

(b) doubled

(c) reduced to zero

(d) increased by 10 folds

I had been asked this question in my homework.

My question is taken from Enzyme Kinetics Fundamentals in section Enzyme Kinetics Fundamentals of Enzyme Technology

Answer 1

The correct answer is (a) reduced to half

The best I can explain: The enzyme catalyzed reaction which involves dissolved gases is influenced by solubility of gases, difference in molar volumes between reactants and products and volume changes occurring during binding and catalysis. In some reactions, the volume may get reduced to 50 ml/mol due to conformational changes and changes in hydration. This in turn leads to doubling of Kcat and halving of Km. In this way, changes in pressure also affects the enzyme catalyzed reaction.