The muscle isozyme of lactate dehydrogenase is inhibited by lactate. Steady state kinetic analysis yielded the following data, with lactate either absent or present at a fixed concentration.
(a) Pyruvate is the substrate whose concentration is varied in one plot, NADH in the other. Identify each. Use an arrow and the appropriate letter (b, c, d, or e) to identify each of the following.
(b) Reciprocal of Vₘₐₓ for the uninhibited enzyme.
(c) The line representing data obtained in the presence of lactate acting as a competitive inhibitor with respect to the variable substrate.
(d) The line representing data obtained in the presence of lactate acting as a mixed inhibitor with respect to the variable substrate.
(e) Reciprocal of Kₘ in the presence of lactate acting as a competitive inhibitor.
