Allosteric Regulation in Enzymes
What are the two models of allosteric regulation in enzymes?
A) Sequential: Cooperativity B) Sequential: Multiple Subunits C) Concerted: No Cooperativity D) Concerted: Single Subunit
Answer:
The two models of allosteric regulation in enzymes are the sequential and concerted models.
Allosteric regulation can be categorized into sequential and concerted models. Sequential models exhibit cooperativity and multiple subunits, while concerted models lack cooperativity and have a single subunit.
Examples of enzymes in the sequential model include hemoglobin and phosphofructokinase, while enzymes in the concerted model include citrate synthase and aspartate transcarbamoylase.
Explanation:Allosteric regulation of enzyme activity can be categorized into two models: sequential and concerted. The sequential model is characterized by cooperativity and multiple subunits, while the concerted model has no cooperativity and a single subunit.
In the sequential model, the binding of one substrate molecule to an active site induces a conformational change that increases the affinity of other active sites for substrate binding. This results in an allosteric effect on enzyme activity.
Examples of enzymes that follow the sequential model include hemoglobin and phosphofructokinase. On the other hand, in the concerted model, the binding of a regulator molecule to an allosteric site causes a simultaneous conformational change in all active sites of the enzyme, leading to a global effect on enzyme activity.
Examples of enzymes that follow the concerted model include citrate synthase and aspartate transcarbamoylase.