Kerry Loombs - Lecture 2, 3 Flashcards
Insulin is produced by
Islet beta cells in the pancreas
Insulin is secreted in response to high or low blood glucose levels
High blood glucose levels
What does Insulin do
Glucose from the circulation is converted into glycogen in the liver and muscle
Glucagon is produced by
Islet alpha cells of the pancreas
Glucagon is secreted in response to high or low blood glucose levels
Low blood glucose levels
What does Glucagon do?
Glycogen break down in the LIVER to produce glucose that enters the circulation
(It does NOT act on muscle as there are no receptors present)
Does Glucogon act on the liver, muscle or both
Liver only, no receptors in the musce
Adrenaline (Epinephrine) is produced by
the Adrenal Glands
Skeletal Muscle produces energy through
Glycolysis
Skeletal muscle breaks down or produces glucose
Skeletal muscle breaks down Glucose
Does the Liver breaks down or produces glucose
The liver produce glucose
How does the Liver produce Glucose?
Through glycogenolysis or gluconeogenesis
What does the enzyme Phosphofructokinase do?
- Convert Fructose-6-phosphate to Fructose-1,6-bisphosphate (fructose-1,6-P2)
- This is 1 of the irreversible steps in Glycolysis
What does Pyruvate kinase do?
- Convert Phosphoenolpyruvate (PEP) into Pyruvate
- An irreversable step in Glycolysis
Pyruvate Kinase is present as Type L and Type M, what does this mean
Type L predominates in the LIver
Type M predominates in muscle and the Brain
What are the 3 domains in the Bifunctional enzyme?
Regulatory domain, Kinase domain and phosphatase domain
Two of the 3 domains in the bifunctional polypeptide chain produce enzymes what are they?
- Kinase domain produces Phosphofrutokinase-2 (PFK2) which catalyses the formation of Fructose-2,6-bisphosphate
- Phosphatase domain produces fructose-2,6-bisphosphatase which catalyses the reformation of fructose-6-phosphate
Of the 2 products produced by the bifunctional enzyme what one stimulates Glycolysis
Fructose-2,6 bisphosphate
Can Epinephrine can act on both the liver and skeletal muscle,
Yes
____ can release glucose into the blood stream. _____ cant release glucose into the blood stream because it lacks glucose-6-phosphatase
The Liver can release glucose into the blood stream. Skeletal muscle cant release glucose into the blood stream because it lacks glucose-6-phosphatase
