Allosteric Regulation and Respiration Basics

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Which of the following is NOT a characteristic of allosteric regulation of enzymes?

Exhibits sigmoidal kinetics
Leads to a linear relationship between substrate concentration and enzyme activity (correct)
Involves a regulatory subunit that is separate from the catalytic subunit
Allows for positive feedback regulation

In the case of uncompetitive inhibition of an enzyme, the inhibitor:

Binds to the enzyme-substrate complex, decreasing the Vmax (correct)
Binds to the enzyme, decreasing the Km
Binds to the substrate, preventing it from binding to the enzyme
Binds to the enzyme, decreasing the Vmax

Which type of enzyme inhibition results in a decrease in the Km of the enzyme?

Noncompetitive inhibition
Uncompetitive inhibition
Allosteric inhibition
Competitive inhibition (correct)

Which of the following is a characteristic of noncompetitive inhibition of an enzyme?

The inhibitor binds to the enzyme, decreasing the Vmax (B) Signup and view all the answers

What is the purpose of allosteric regulation in enzymes?

To allow for feedback regulation of the enzyme (A) Signup and view all the answers

Which of the following is a consequence of positive allosteric regulation of an enzyme?

Sigmoidal kinetics (D) Signup and view all the answers

What is the primary factor that regulates the activity of the enzyme phosphofructokinase (PFK) in the glycolysis pathway?

The levels of ADP and AMP in the cell (D) Signup and view all the answers

How does the binding of ATP to phosphofructokinase (PFK) affect the enzyme's activity?

ATP binds to PFK in an allosteric manner, decreasing its activity (C) Signup and view all the answers

Which of the following statements about the effects of citrate on phosphofructokinase (PFK) activity is correct?

Citrate binds to PFK in an allosteric manner, decreasing its activity (A) Signup and view all the answers

Which type of enzyme inhibition is exhibited by the binding of ADP and AMP to phosphofructokinase (PFK)?

Allosteric inhibition (C) Signup and view all the answers

How does the binding of citrate to phosphofructokinase (PFK) affect the enzyme's activity?

Citrate binds to PFK in an allosteric manner, decreasing its activity (D) Signup and view all the answers

Which of the following statements about the regulation of phosphofructokinase (PFK) activity is correct?

PFK is inhibited by high levels of ADP and AMP, indicating the cell has sufficient energy (D) Signup and view all the answers

Which of the following statements about competitive inhibitors is correct?

Competitive inhibitors increase the Michaelis constant (Km) of the enzyme reaction. (D) Signup and view all the answers

What is the effect of a non-competitive inhibitor on an enzyme reaction?

It decreases the maximum velocity (Vmax) but does not affect the Michaelis constant (Km). (C) Signup and view all the answers

Which of the following statements about uncompetitive inhibitors is true?

Uncompetitive inhibitors bind to the enzyme-substrate complex, preventing product formation. (B) Signup and view all the answers

Which of the following factors can affect enzyme activity?

All of the above (D) Signup and view all the answers

What is the difference between allosteric regulation and inhibition in enzymes?

Allosteric regulation involves binding of a molecule to a regulatory site, causing a conformational change, while inhibition involves direct blocking of the active site. (C) Signup and view all the answers

What is the relationship between the Michaelis constant (Km) and substrate affinity?

As Km increases, substrate affinity decreases. (D) Signup and view all the answers