Glycogen synthesis Flashcards
Where is excess carbs stored?
As glycogen in liver and the muscle
When glycogen reserves are full how is excess carbs stored?
As fat
what is the function of glycogen in liver
maintenance of blood glucose between meals and during early stages of fasting
what is the function of glycogen in muscle
fuel reserve for muscle contraction
Is the glucose released from the liver glycogen exportable?
Released into blood to be used by other tissues
Is the glucose released from the muscle glycogen exportable?
cannot leave the muscle- enters glycolysis
Hormonal control of liver glycogen
Glucagon and adrenaline promotes breakdown.
Insulin promotes synthesis
Hormonal control of muscle glycogen
Adrenaline promotes breakdown.
Insulin promotes synthesis.
What happens when the glycogen storage is full
converted into fat.
Excess glucose is converted into pyruvate & forms acetyl coenzyme A, excess acetyl CoA forms fatty acids (fat).
Which enzymes are involved in the activation of glucose
- hexokinase
- phospho- glucosmutase
- UDP- Gucose pyrophosphorylase
What is the end result when glucose is activated
UDP- Glucose
Which Enzymes in the activation of glucose require energy
- hexokinase ( ATP–> ADP)
2. UDP-Glucose pyrophosphorylase (UTP—> Pi)
What enzyme controls the addition of UDP glucose to glycogen
glycogen synthase
What is glycogen synthase controlled by
Glucose 6-phosphate
How does Glucose- 6 phosphate control glycogen synthase
o If there is plenty of glucose around, there will be a surplus of glucose 6 – phosphate that isn’t being used in glycolysis so promotes glycogenesis by activating glycogen synthase
