Question

what is the main mechanism of substrate binding to enzymes?
random diffusion
induced fit
surface interactions
competitive inhibition

Explanation:

The induced - fit model is the widely - accepted main mechanism. In this model, the binding of the substrate to the enzyme causes a conformational change in the enzyme's active site to better fit the substrate. Random diffusion is a process related to how molecules move, surface interactions are more general and not the main binding mechanism, and competitive inhibition is about an inhibitor competing with the substrate for the active site, not the binding mechanism itself.

Answer:

induced fit