Glycogenesis

Question 1

What are the three steps and enzymes involved in glucose activation?

Answer 1

1) Glucose – hexokinase –> Glucose 6 phosphate
2) G6P – phosphoglucomutase –> Glucose 1 phosphate
3) G1P + UDP – glucose 1 phosphate uridyltransferase –> G1-UDP + PP

Question 2

Name the process and (2) enzymes responsible for building glycogen

Answer 2

Glycogen synthase (G1-UTP -- GS --> G1 + G1; no P or UTP
Glycogen Brancher - will remove 7 glucose moities and form A-1,6 linkage (i.e. branch), approx Q4G

Question 3

What are the three ways glycogen degradation and synthesis is regulated. *gimme the subtypes

Answer 3

Enzymes - Glycogen phosphatase, Glycogen Synthase
Hormones - Insulin (+), Epinephrine (-) Glucagon (-)
Allosteric

Question 4

Explain the hormonal regulation of glycogen breakdown

Answer 4

Glycogen (receptor) & Epinephrin (A/B adrenergic receptor).
Activate G-Protein –> Adenyl Cyclase –> cAMP–> pKA
PKA –>((P)) –> {glycogen phosphorylate kinase} - active
active glycogen phosphorylate kinase –> ((P)) glycogen phosphorylase (main glycolysis enzyme)

Question 5

Explain the hormonal regulation of glycogen synthesis

Answer 5

Glycogen (receptor) & Epinephrin (A/B adrenergic receptor).
Activate G-Protein –> Adenyl Cyclase –> cAMP–> pKA
PKA –>((P)) –> {glycogen synthase} - INactive

Insulin activates protein phosphatase - 1 –> active

Question 6

Glycogeneis is run when the body ______ energy?
Glycolysis is run when the body ______ energy?

LIST 1, 2 Regulators respectively

Answer 6

has energy; Glucose-6-phosphate

needs energy; AMP, CA++

Question 7

Hypoglycemia in Infants (why is it especially bad (4))

Answer 7

1) Brain Body Ratio - Need a lot of glucose for brain
2) Limited ketoneogenesis - need glucose
3) Limited gluconeogenesis
4) Limited glycogen stores (especially in premature babies)