induced fit model and lock and key model

It possesses a unique conformation (including correctly positioned bonding groups) that is complementary to the structure of the substrate, so that the enzyme and substrate molecules fit together in much the same manner as a key fits into a tumbler lock. of the enzyme ( Figure 18.10 'Substrate Binding to the Active Site of an Enzyme'). This pocket, where the enzyme combines with the substrate and transforms the substrate to product is called the active site The location on an enzyme where a substrate binds and is transformed to product. The structural features or functional groups on the enzyme that participate in these interactions are located in a cleft or pocket on the enzyme surface.

Hydrogen bonding and other electrostatic interactions hold the enzyme and substrate together in the complex.

(This step is reversible because the complex can break apart into the original substrate or substrates and the free enzyme.) Once the E–S complex forms, the enzyme is able to catalyze the formation of product (P), which is then released from the enzyme surface: S + E → E–S E–S → P + E In the first step, an enzyme molecule (E) and the substrate molecule or molecules (S) collide and react to form an intermediate compound called the enzyme-substrate (E–S) complex.

Describe the interaction between an enzyme and its substrate.Įnzyme-catalyzed reactions occur in at least two steps.

Induced fit model and lock and key model