Enzyme Action & Specificity | Biology for GCSE/IGCSE - Year 11 PDF Download

Enzyme Action & Specificity: Extended

• Enzymes exhibit specificity to particular substrates due to the complementarity between the active site of the enzyme, where the substrate binds, and the substrate itself.
• The unique three-dimensional structure of enzymes, being proteins, underpins their specificity.
• This concept is encapsulated in the lock and key hypothesis.
• Upon the substrate binding to the active site, it forms an enzyme-substrate complex.
• Following the reaction, the products disengage from the active site, facilitated by their altered shape, rendering the enzyme available to bind another substrate.

How Enzymes Work

Enzymes Work Process:

• Enzymes and substrates exhibit random movement within a solution.
• When an enzyme and its corresponding substrate collide randomly, and the substrate fits into the enzyme's active site, an enzyme-substrate complex is generated, initiating the reaction.
• Subsequently, products emerge from the substrates within the active site, and upon release, the enzyme remains unaltered, available to catalyze subsequent reactions.