BIOL 540 Exam 4 QUESTIONS WITH ANSWERS!!

BIOL 540 Exam 4 QUESTIONS WITH
ANASWERS!!
glycogen phosphorylase - ANSWER- allosteric regulation
- exists in active form a and inactive form b

AMP - ANSWERpositive effector of glycogen phosphorylase

calcium - ANSWERpositive effector for glycogen phosphorylase kinase

glucagon (in liver) - ANSWER- activates glycogenolysis
- inhibits glycolysis
- increases blood glucose

pyruvate kinase - ANSWERstep in glycolysis directly inhibited by protein kinase A

epinephrine - ANSWER- in liver: increases blood glucose
- alpha and beta adrenergic receptors (different mechanistic response)


glycogen phosphorylase kinase - ANSWERphosphorylates glycogen phosphorylase
(adds phosphate)

phosphoprotein phosphatase - ANSWERenzyme that removes a phosphate from a
protein, dephosphorylates glycogen phosphorylase kinase and glycogen
phosphorylase

insulin - ANSWER- positive effector of phosphoprotein phosphatase
- directly inactivates protein kinase A
- degrades cAMP by activating cAMP phosphodiesterase activation (derepresses the
repressor, unphosphorylated)

glycogen synthase - ANSWER- allosteric regulation
- inactive when phosphorylated
- active when dephosphorylated

glucose 6 phosphate - ANSWERpositive effector of glycogen synthase

calcium - ANSWERpositive effector of phosphorylase kinase, calmodulin-dependent
protein kinase, and protein kinase C

phosphoprotein phosphatase - ANSWER- highest activity requires catalytic and
regulatory subunit
- regulatory protein G
- catalytic subunit is completely inactivated by interaction with a phosphorylated
inhibitor