Catalysis

Lock and key

Induced fit

Conformational change

Broad specificity of enzymes

Narrow specificity of enzymes

Rigid structure of enzymes

Rigid structure of substrate

The active site fits perfectly with the substrate

The active site is static

There is a transition state during which the shape of the active site changes to better fit the substrate

The enzyme does not have a separate catalytic group

The enzyme and substrate have complementary geometric shapes and are specific to one another

There is broad specificity of enzymes

Enzymes cannot be reused

The active site of the enzyme undergoes conformational change when the substrate binds

Stabilization of transition state, lowering activation energy

Stabilization of transition state, increasing activation energy

Increase enthalpy of reaction

Decrease yield of reaction

Lock and key model

Induced fit

Enzyme substrate model

Conformation model