When dealing with stable isotopes, enzymes tend to favor
A) the heavier isotope.
B) the lighter isotope.
C) the isotopes in about equal proportions.
D) either the lighter or the heavier isotope, depending on environmental conditions.

Question

Quizplus · Accepted Answer

Enzymes tend to favor the lighter isotope because it requires less energy to break the bond between the lighter isotope and its attached atom, allowing the reaction to proceed more quickly. This is known as the kinetic isotope effect.

When Dealing with Stable Isotopes, Enzymes Tend to Favor