Describe the reactions catalyzed by lactate dehydrogenase in the skeletal muscles, liver, and heart.

Lactate dehydrogenase is an enzyme that can:

• catalyzes the conversion of lactate to pyruvate and back, and

• converts NAD + to NADH and back.

The reaction of lactate dehydrogenase usually occurs during a tissue damage. So, pyruvate, (the final product of glycolysis), is converted to lactate when oxygen is absent (in low concentration).

When the concentrations of lactate increases (as the product of lactate dehydrogenase reaction), the enzyme exhibits feedback inhibition (negative feedback).