Nov 12 2024 45 mins
In this episode, we explore enzyme kinetics and inhibition, key concepts for the MCAT Bio/Biochem section. We’ll cover how enzymes accelerate biological reactions by lowering activation energy and introduce two models for enzyme-substrate interaction: the lock-and-key model and the induced fit model.
You'll learn how to apply the Michaelis-Menten equation, focusing on factors like Km and Vmax to understand enzyme efficiency and substrate binding. We’ll also break down the different types of enzyme inhibition—competitive, non-competitive, and uncompetitive—and their effects on enzyme activity. Finally, we discuss the six major types of enzymes and their roles in biological processes, with examples like ligases, isomerases, and hydrolases.
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Jump into the conversation:
(00:00) Introduction to enzyme kinetics and inhibition
(01:58) Definition of enzymes and their role
(03:50) Enzyme models: lock and key vs. induced fit
(06:28) Michaelis-Menten Equation
(10:53) Association and dissociation constants
(12:34) Kcat and catalytic efficiency
(14:43) Assumptions of Michaelis-Menten
(18:23) Lineweaver-Burk Plot: linearized Michaelis-Menten Equation
(21:09) Enzyme inhibition: reversible vs. irreversible
(22:14) Competitive inhibition: Km and Vmax
(24:46) Non-competitive inhibition: Effects on Km and Vmax
(27:20) Irreversible inhibition
(29:13) Allosteric inhibition
(31:26) Homotropic and feedback inhibition
(37:40) Common biological enzymes: dehydrogenase, synthetase, and kinase
(43:44) MCAT Advice of the Day