Question

7. Provide ONE example of "allosteric control" and ONE example of "covalent control that occurs in glycogenolysis, OR glycogen synthesis (your choice!) and BRIEFLY describe how this control responds to changes in the concentrations of metabolites in the cell. (6 points) a. Allosteric control: b. Covalent control:

Answer 1

Solution:

Allosteric control:

In allosteric control, the activity of enzymes can be affected by the binding of small molecules to the enzyme. The molecules bind at a place on the enzyme other than the active site.

Gycogen synthesis reaction is highly regulated by allosteric effectors such as glucose-6-phosphate and phosphorylation reactions . Glucose-6-phosphate works as allosteric activator while phosphorylation works as an allosteric deactivator in which hormone glucagon, which is secreted by the pancreas, decreases blood glucose levels.

Covalent control:

Some enzymes are synthesized in a completely inactive form and their activation requires covalent bonds in them to be cleaved. In covalent control reactions, the harmones are responsible to control the reactions.

The hormones bind to their membrane receptors and amplify the magnitudes of their signal, stimulating glycogenolysis and inhibiting glycogen synthesis.