Enzymes: Catalysis, Kinetics & Classification – Biochemistry | Lecturio

Summary

An in-depth look at enzyme function, including mechanisms of catalysis, the kinetics of reaction rates, and the systematic classification of enzymes.

Highlights

Introduction to Enzymatic Catalysis00:00:00

Overview of enzyme function and the fundamental differences between chemical catalysts and enzymes, emphasizing enzyme flexibility and the Koshland induced fit model.

Activation Energy and Mechanisms00:07:10

Discussion on how enzymes lower activation energy to facilitate reactions. Detailed mechanism of serine proteases using the catalytic triad and the oxyanion hole.

Michaelis-Menten Kinetics00:23:17

Explanation of enzyme reaction kinetics, including the importance of initial velocity (V0), steady-state conditions, and how to interpret the hyperbolic plot of substrate concentration versus velocity.

Kinetic Parameters: Vmax, Km, and Kcat00:34:55

Definition and analysis of kinetic parameters: Vmax (maximum velocity), Km (affinity of enzyme for substrate), and Kcat (turnover number). Discussion on perfect enzymes and the Lineweaver-Burk plot.

Allosteric Enzymes and Binding Models00:50:07

Exploration of allosteric regulation, the R (relaxed) and T (tense) states, and the differences between the concerted and sequential models of enzyme behavior.

Substrate Binding and Enzyme Classification00:57:49

Review of binding mechanisms including ordered and ping-pong pathways, followed by the six systematic classifications of enzymes defined by the Enzyme Commission.