11 - Enzyme Kinetics

Enzyme Kinetics Lecture Notes

Overview: BIOC 2300 Lecture 11 by David N. Langelaan covering enzyme kinetics.

Enzymes and Drug Targets: Enzymes are vital for a $200 billion market; they serve as drug targets due to favorable binding clefts and their catalytic role.

Enzyme Inhibition: Enzymes can be poisoned (e.g., by Amanita phalloides). Key topics include enzyme-catalyzed reactions, rate equations, Michaelis-Menten equation (noting Km and Vmax), enzyme efficiency (kcat/Km), and both reversible (competitive and non-competitive) and irreversible inhibitors (e.g., Diisopropylfluorophosphate).

Key Concepts:

• Velocity equations: Relate to concentration (unimolecular and bimolecular reactions).

• Michaelis-Menten Equation: v = Vmax[S] / (KM + [S]). Km indicates substrate binding affinity.

• Catalytic Rate Constant (kcat): Indicates speed of enzyme action; kcat = Vmax / [E]total.

• Types of Inhibition: Competitive increases Km, non-competitive lowers Vmax, while mixed affects both.

• Allosteric Regulation: Involves cooperativity affecting Vmax and Km.

Session Objectives: Understanding enzyme kinetics, inhibition mechanisms, and their regulatory processes.

Vocabulary: Essential terms like enzyme, substrate, Km, Vmax, kcat.