Question

Allosteric regulation of key enzymes in glycolytic and gluconeogenesis pathways may involve each of the following except

A) activating the enzyme activity.
B) inhibiting the enzyme activity.
C) binding of the allosteric regulator molecule to directly compete with substrate binding in the enzyme active site.
D) binding of the allosteric regulator molecule to a site on the enzyme other than the active site.
E) Any of the above may be involved.

Answer 1

Allosteric regulation of key enzymes in glycolytic and gluconeogenesis pathways involves activating and inhibiting enzyme activity, as well as binding of allosteric regulator molecules to sites on the enzyme other than the active site. However, allosteric regulators do not directly compete with substrate binding in the enzyme active site. Allosteric effectors such as ATP, ADP, AMP, NAD+, and NADH can increase or decrease enzyme activity by causing conformational changes in the enzyme.

Step-by-step explanation:

Allosteric regulation of key enzymes in glycolytic and gluconeogenesis pathways may involve activating the enzyme activity, inhibiting the enzyme activity, and binding of the allosteric regulator molecule to a site on the enzyme other than the active site. All of these are examples of allosteric regulation except binding of the allosteric regulator molecule to directly compete with substrate binding in the enzyme active site. Allosteric regulation involves a molecule binding to an allosteric site on the enzyme, causing a conformational change that affects substrate binding and reaction rates. The allosteric effectors, such as ATP, ADP, AMP, NAD+, and NADH, can either increase or decrease enzyme activity depending on the conditions.