Endocrine control of metabolism Flashcards
(21 cards)
Why is prolonged hyperglycemia dangerous?
Causes non enzyme controlled glycation reactions
Causes structural damage in proteins
How much glucose does the brain consume per hour?
30 mmol
How much glucose does the skeletal muscle consume per hour?
300mmol
What are the two sources of plasma glucose?
Diet
Organs that export glucose into circulation
What are the two phases of metabolism?
Absoptive phase (fed state)
Post-absoptive (fasting state)
Is insulin anabolic or catabolic?
anabolic hormone
What is lipogenesis?
Synthesis of fatty acids from acetyl CoA
What is triglyceride synthesis?
Esterification of fatty acid for storage as triglyceride
What is beta oxidation of fatty acids
Turns free fatty acids into acetly CoA
Enters TCA cycle
What is produced from what in ketogeneis?
Ketone bodies are made from Acetyl CoA
What does insulin inhibit?
*release of glucose from liver
* inhibits fat and protein breakdown (lipolysis/proteolysis)
What are the stimulatory effects of insulin?
- liver glycogenesis
- liver lipogenesis
- glucose uptake in muscle and adipose tissue
In the short term, what happens when there is a fall in plasma glucose concentration?
Release of glucagon
In the medium term, what happens when there is a fall in plasma glucose concentration?
- gluconeogenesis
- lipolysis + FA oxidation
- ketogenesis
In the long term, what happens when there is a fall in plasma glucose concentration?
proteolysis
Why is glucose immediately converted into glucose-6-phosphate in the cell
To maintain glucose conc gradient
When in need of energy, what happens to triglycerides?
norepinepherine can mobilise triglycerides back into fatty acids
Via which transporter does glucose diffuse into skeletal muscle?
GLUT 4 (insulin dependant)
Process of triglyceride production from fatty acids in the liver
Fatty acids transported into liver
Converted to fatty acyl-CoA
glycerol-3-phosphate is added to form triglycerides
Leaves the liver to become VLDL
What happens to fatty acyl CoA if the energy demand is immediate? (low insulin high glucagon)
Beta oxidation stimulated by glucagon
Becomes ketone bodies
Ketogenesis
What happens when insulin is high and glucagon is low
New fatty acids are synthesised via lipogenesis
Glucose - acetyl CoA - malonyl CoA - fatty acyl CoA - triglycerides
