What role does allosteric regulation play in the activity of glycogen phosphorylase?

• A. Allosteric regulation is responsible for the synthesis of glycogen.
• B. Allosteric regulation is unrelated to enzyme activity.
• C. Allosteric regulation involves the phosphorylation of serine residues.
• D. Allosteric regulation involves the binding of effectors that can activate or inhibit the enzyme.

Answer: (D)