Exemplar Problems

Question:

Describe the mechanisms of enzyme regulation, including competitive and non-competitive inhibition, and provide real-life examples of each.

Answer:

Enzyme regulation involves various mechanisms:

• Competitive Inhibition: Competitive inhibitors resemble the substrate and compete for the enzyme’s active site. An example is methotrexate, which competes with the substrate folic acid in the synthesis of DNA precursors.

• Non-competitive Inhibition: Non-competitive inhibitors bind to an allosteric site on the enzyme, altering its conformation and reducing activity. An example is cyanide, which binds to the allosteric site of cytochrome c oxidase in the electron transport chain.