Question

Glycogen phosphorylase

Mechanisms of regulation
1. Allosteric modifiers:
inhibitors: ___________ & ___________ for phosphorylase b; ___________ for phosphorylase a-->create less active form or (R/T?) state
activator: ___________--->create more active form or (R/T?) state
a. G6P
b. ATP
c. glucose
d. AMP
2. Covalent modification:
phosphorylase a has a ____________ attached to phosphoserine residues.
phosphorylase b is the ___________ form of this enzyme.
a. dephosphorylated
b. phosphate

Answer 1

Glycogen phosphorylase is regulated through allosteric modifiers and covalent modification. Inhibitors like glucose-6-phosphate and ATP create a less-active form of the enzyme, while activators like AMP create a more active form. Phosphorylation and dephosphorylation of phosphoserine residues also play a role in enzyme regulation.

Step-by-step explanation:

Glycogen phosphorylase is regulated by various mechanisms.

1. Allosteric modifiers inhibit or activate the enzyme. Inhibitors for phosphorylase b include glucose-6-phosphate (G6P) and ATP, while activators include AMP. These modifiers create less or more active forms of the enzyme, respectively.
2. Covalent modification involves phosphorylation of phosphoserine residues. Phosphorylase a has a phosphate attached, while phosphorylase b is the dephosphorylated form. Phosphorylation results in a less-active enzyme, and dephosphorylation reactivates it.