Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

7. Enzyme Inhibition and Regulation

Enzyme Inhibition

Biochemistry

7. Enzyme Inhibition and Regulation

Enzyme Inhibition

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Multiple Choice

Which of the following statements about inhibitors of enzyme-catalyzed reactions is true?

Competitive inhibitors increase the apparent $K_m$ but do not affect $V_{max}$.

Noncompetitive inhibitors decrease the $K_m$ of the enzyme.

Uncompetitive inhibitors bind only to the free enzyme, not the enzyme-substrate complex.

Competitive inhibitors bind to an allosteric site on the enzyme.

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Verified step by step guidance

Step 1: Begin by understanding the types of enzyme inhibitors mentioned in the problem: competitive, noncompetitive, and uncompetitive inhibitors. Each type affects enzyme kinetics differently, specifically the Michaelis constant ($K_m$) and maximum velocity ($V_{max}$).

Step 2: Recall that competitive inhibitors bind to the active site of the enzyme, competing with the substrate. This increases the apparent $K_m$ (substrate concentration required to reach half $V_{max}$) because more substrate is needed to outcompete the inhibitor. However, $V_{max}$ remains unchanged because the inhibitor can be overcome at high substrate concentrations.

Step 3: Noncompetitive inhibitors bind to an allosteric site, not the active site, and can bind to both the free enzyme and the enzyme-substrate complex. They decrease $V_{max}$ because they reduce the overall number of active enzyme molecules, but they do not affect $K_m$ since substrate binding is not directly hindered.

Step 4: Uncompetitive inhibitors bind only to the enzyme-substrate complex, stabilizing it and preventing the reaction from proceeding. This decreases both $K_m$ and $V_{max$, as the enzyme-substrate complex is less likely to release the product.

Step 5: Evaluate the statements provided in the problem based on the definitions and effects of each type of inhibitor. Competitive inhibitors do not bind to allosteric sites, and noncompetitive inhibitors do not decrease $K_m$. The correct statement is that competitive inhibitors increase the apparent $K_m$ but do not affect $V_{max}$.