Ch. 7 - Enzyme Inhibition and Regulation WorksheetSee all chapters
All Chapters
Ch. 1 - Introduction to Biochemistry
Ch. 2 - Water
Ch. 3 - Amino Acids
Ch. 4 - Protein Structure
Ch. 5 - Protein Techniques
Ch. 6 - Enzymes and Enzyme Kinetics
Ch. 7 - Enzyme Inhibition and Regulation
Ch. 8 - Protein Function
Ch. 9 - Carbohydrates
Ch. 10 - Lipids
Ch. 11 - Biological Membranes and Transport
Ch. 12 - Biosignaling
Clutch Review 1: Nucleic Acids, Lipids, & Membranes
Clutch Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway
Clutch Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism
Clutch Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation
Enzyme Inhibition
Irreversible Inhibition
Reversible Inhibition
Inhibition Constant
Degree of Inhibition
Apparent Km and Vmax
Inhibition Effects on Reaction Rate
Competitive Inhibition
Uncompetitive Inhibition
Mixed Inhibition
Noncompetitive Inhibition
Recap of Reversible Inhibition
Allosteric Regulation
Allosteric Kinetics
Allosteric Enzyme Conformations
Allosteric Effectors
Concerted (MWC) Model
Sequential (KNF) Model
Negative Feedback
Positive Feedback
Post Translational Modification

Concept #1: Competitive Inhibition

Concept #2: Competitive Inhibitor Effects

Concept #3: Competitive Inhibition & Michaelis-Menten-Plots

Concept #4: Competitive Inhibition & Lineweaver-Burk-Plots

Practice: Which of the following would be altered on a Lineweaver-Burk plot in the presence of a competitive inhibitor?

Practice: N-hydroxy-L-arginine (an intermediate in nitric oxide biosynthesis) can bind to the active site of arginase making its manganese reactive metal center unavailable for catalysis. How would an increased concentration of this intermediate be expected to affect the kinetic parameters of this enzyme?

Practice: An enzyme has a Km of 8 ฮผM in the absence of a competitive inhibitor and a K ๐ฆ๐š๐ฉ๐ฉ of 12 ฮผM in the presence of 3 ฮผM of the inhibitor. Calculate the KI.

Practice: Use the Lineweaver-Burk plot below to answer the following questions. Units of [S] are in nM.

A) Estimate the values of Km & Vmax as well as the K๐ฆ๐š๐ฉ๐ฉ & V๐ฆ๐š๐ฑ๐š๐ฉ๐ฉ for the reactions in the absence and presence of the competitive inhibitor.

B) Would you expect the competitive inhibitor to be more effective under conditions of high or low [S]? Why?

C) If [I] = 10 nM, calculate the inhibition constant (K I).