Biochemistry 4th Edition by Reginald Garrett, Charles Grisham

Exercise 16

Assessing the equilibrium concentrations in the malate dehydrogenase reaction
A typical intramitochondrial concentration of malate is 0.22 mM. If the ratio of NAD + to NADH in mitochondria is 20, and if the malate dehydrogenase reaction is at equilibrium, calculate the concentration of oxaloacetate in the mitochondrion at 20°C. A typical mitochondrion can be thought of as a cylinder 1 µm in diameter and 2 µm in length. Calculate the number of molecules of oxaloacetate in a mitochondrion. In analogy with pH (the negative logarithm of [H + ]), what is pOAA