Chapter 8: 8.2 Hormonal Metabolic Regulation Flashcards
Define:
Hormone Metabolic Regulation
Signals determining whether the catabolic or the anabolic pathways are activated
What is involved in Catabolic Hormone Signalling?
- Epinephrine/Adrenaline
- Glucagon
Define:
Epinephrine/Adrenaline
Secreted from the medulla of the adrenal glands
* Regults in glycogen breakdown in muscles, increases energy production
What is the purpose of Epinephrine/Adrenaline in Catabolic Hormone Signalling?
ATP production
Define:
Glucagon
When blood sugar levels are low, glucagon is released (from alpha cells in the pancreas)
* Signals glycogen breakdown
What is the purpose of Glucagon in Catabolic Hormone Signalling?
Increases blood sugar levels
Define:
Glycogenolysis
Glycogen is cleaved by phophorylated glycogen phosphorylase into glucose-1-phosphate (G1P) from non-reducing ends
Where are the products of glycogenolysis used?
- Glycolysis (first has to be converted to glucose-6-phosphate)
- Released into the bloodstream
What is involved in Anabolic Hormonal Regulation?
Insulin
Define:
Insulin
Secreted from the β cells in the pancreas
* Stimulates glucose uptake by cells
What processes are insulin involved in?
(2 points)
- Glycolysis
- Glycogen and fat synthesis
Describe:
How insulin is produced in β cells
(5 points)
- Glucose enters cell and leads to ATP production
- ATP blocks K+ channels
- Calcium enters the cell and signals for insulin secretion
- Insulin synthesized as an inactive precursor (modified in the ER and golgi)
- Insulin and c-peptide are released from cell
What are the 2 responsibilities of insulin?
- Recruits GLUT transporters for glucose import into the cell
- Stimulates glycogen/fat synthesis and inhibits glycogen/fat breakdown
Does the mechanism of action by insulin stay the same for different cell types?
No, mechanisms of action varies by cell type
In Anabolic Hormonal Regulation:
What happens to glucose?
Glucose is activated to G6P and converted to G1P via phosphoglucomutase
