This crevice is the active side of the lactate dehydrogenase. And what must happen is this coenzyme, the NADH, will bind into the active side of that enzyme first before the pyruvate actually binds. Only then, only when we bind the NADH into the active side, can the pyruvate actually move into the active side and bind into the active side. And once the pyruvate moves in, we form this ternary structure in which we have the pyruvate and the NADH inside the active side. Of that enzyme. Once again, ternary simply means we have three molecules, the enzyme and the two substrate molecules.