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
Sections
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
Ubiquitination
Phosphorylation
Zymogens

Concept #1: Positive Feedback

Practice: The reaction Fructose-6-P + ATP <===> ADP + Fructose-1,6-bisP is catalyzed by the glycolytic enzyme phosphofructokinase-1 (PFK-1). In muscle tissue, PFK-1 is a homotetramer (contains 4 identical subunits). Adenosine monophosphate (AMP) binds at a site distant from the site of catalysis on any of the four subunits & induce a conformational change that favors a relaxed & more active state of the whole tetramer. How is the role of AMP classified in this reaction?

Concept #2: Metabolic Pathway Communication

Practice: Use the image below showing interactions between 3 metabolic pathways to answer the following questions.

A) Which of the following best describes the role of molecule “F”?

a) At low concentrations, molecule F acts as an inhibitor on enzyme-1 & an activator on enzyme-6.
b) At high concentrations, molecule F acts as an activator on enzyme-1 & an inhibitor on enzyme-6.
c) At low concentrations, molecule F acts as an activator on enzyme-1 & an inhibitor on enzyme-6.
d) At high concentrations, molecule F acts as an inhibitor on enzyme-1 & an activator on enzyme-6.

B) Which of the following best describes the role of molecule “I”?

a) At high concentrations, molecule I acts as an inhibitor on enzyme-6 & an activator on enzyme-1.
b) At low concentrations, molecule I acts as an activator on enzyme-6 & an inhibitor on enzyme-1.
c) At high concentrations, molecule I acts as an activator on enzyme-6 & an inhibitor on enzyme-1.
d) At low concentrations, molecule I acts as an inhibitor on enzyme-6 & an activator on enzyme-1.


C) Which of the following best describes the role of molecule “K”?

a) At low concentrations, molecule K acts as an inhibitor on enzyme-1 & an activator on enzyme-6.
b) At high concentrations, molecule K acts as an inhibitor on enzyme-1 & an inhibitor on enzyme-6.
c) At low concentrations, molecule K acts as an activator on enzyme-1 & an inhibitor on enzyme-6.
d) At high concentrations, molecule K acts as an inhibitor on enzyme-1 & an activator on enzyme-6.