Reversible Inhibition Of Enzyme Activity Flashcards
(26 cards)
What is reversible inhibition of enzyme activity?
A process where the binding of an inhibitor to an enzyme can be reversed, allowing the enzyme to regain its activity.
Name the two main types of reversible inhibition.
Competitive inhibition and non-competitive inhibition.
True or False: In competitive inhibition, the inhibitor binds to the active site of the enzyme.
True.
Fill in the blank: In non-competitive inhibition, the inhibitor binds to a site other than the active site, known as the __________.
allosteric site.
What effect does a competitive inhibitor have on the Km value of an enzyme?
It increases the Km value.
What remains unchanged in non-competitive inhibition?
The Km value remains unchanged.
Describe allosteric regulation of enzyme activity.
Allosteric regulation involves the binding of an effector molecule at a site other than the active site, which induces a conformational change in the enzyme.
What are allosteric activators?
Molecules that increase the activity of an enzyme by binding to an allosteric site.
What are allosteric inhibitors?
Molecules that decrease the activity of an enzyme by binding to an allosteric site.
True or False: Allosteric enzymes typically follow Michaelis-Menten kinetics.
False.
What is the shape of the curve representing allosteric enzyme kinetics?
Sigmoidal.
Define feedback inhibition.
A regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme involved in its synthesis.
What is an example of an allosteric enzyme?
Aspartate transcarbamoylase (ATCase).
How does the presence of a substrate affect allosteric enzymes?
The binding of a substrate can stabilize the active form of the enzyme, increasing its activity.
What is the role of cooperativity in allosteric enzymes?
Cooperativity refers to the phenomenon where the binding of a substrate to one active site affects the binding of substrates to other active sites.
Fill in the blank: __________ is a type of inhibition where the inhibitor and substrate cannot bind simultaneously.
Competitive inhibition.
What is the primary function of allosteric sites?
To regulate enzyme activity through the binding of effector molecules.
True or False: Allosteric regulation can involve both positive and negative effects on enzyme activity.
True.
What happens to the Vmax in non-competitive inhibition?
The Vmax decreases.
Name a physiological condition that can affect enzyme activity through allosteric regulation.
Changes in pH or temperature.
What is the significance of allosteric regulation in metabolic pathways?
It allows for fine-tuning of enzyme activity in response to changes in cellular conditions.
Fill in the blank: An enzyme that can exist in multiple conformations is said to exhibit __________.
conformational flexibility.
What is the effect of an allosteric inhibitor on the enzyme’s affinity for the substrate?
It decreases the enzyme’s affinity for the substrate.
How does temperature affect enzyme activity?
Increased temperature typically increases activity up to a certain point, beyond which denaturation occurs.
