3. Enzymes
Start with Concept to understand a topic, then use Question Bank to check what you know.
Your progress
Sign in to see your mastery and mistakes.
3.1 Mode of Action
3.1.1Enzymes as globular proteins
• Enzymes as globular proteins: intracellular and extracellular
3.1.2Enzyme mode of action
• Mode of action: active site, enzyme-substrate complex, lowering activation energy, enzyme specificity
3.1.3Enzyme action hypotheses
• Lock-and-key hypothesis vs induced-fit hypothesis
3.1.4Enzyme reaction investigations
• Investigate enzyme reactions: measure product formation (catalase) and substrate disappearance (amylase)
3.1.5Colorimetry in enzyme reactions
• Use colorimeter for reactions involving colour changes
3.2 Factors Affecting Enzyme Action
3.2.1Effects on enzyme reaction rate
• Effects on enzyme reaction rate: - Temperature - pH (using buffer solutions) - Enzyme concentration - Substrate concentration - Inhibitor concentration
3.2.2Vmax and Km
• Maximum rate (Vmax) and Michaelis-Menten constant (Km)
3.2.3Reversible inhibitors
• Reversible inhibitors: competitive and non-competitive effects
3.2.4Immobilised enzymes
• Immobilised enzymes in alginate vs free in solution