Regulation Of Glucose Metabolism Flashcards
How does insulin affect glucose uptake in muscle
Increase
How does insulin affect gluconeogenesis
Decrease
How does insulin affect glycolysis in liver
Increase
How does insulin affect glycogen synthesis
Increase
How does insulin affect glycogen breakdown
Decrease
How does insulin affect fatty acid biosynthesis
Increase
How does insulin affect lipolysis
Decrease
How does glucagon affect glycogenolysis in muscle
No change
Definition of glycogenolysis
Breakdown of glycogen into glucose
Why is fructose considered to be nutritionally worse than glucose
It bypasses a major regulatory step of glucose metabolism in the liver by entering the reaction at the triose-phosphate stage. Easily gets converted into fat, leading to fatty liver disease.
What damaged is caused by glycosylated haemoglobin in blood?
Blood vessels get damaged, affecting pretty much every part of the body
Six major symptoms of glycosylated haemoglobin in blood
Retinopathy, neuropathy, nephropathy, stroke, heart attack, peripheral vascular disease
What nutrients can the brain eat
Glucose, and in the case of starvation, ketone bodies
What nutrients can the liver eat
Everything
What nutrients can muscle eat
Glucose, fatty acids and ketone bodies
What nutrients can the digestive system eat (e.g. intestines)
Glutamine, ketone bodies and fatty acids
What nutrients can the heart eat
Fatty acids, lactate, ketone bodies and glucose
What nutrients can the kidney eat
Fatty acids, glutamine and glucose
What happens in the liver during an advanced fasting state and diabetes?
Glucose is produced from numerous processes. From adipose, glycerol is turned into glucose, and fatty acids are made and turned into ketone bodies for the brain. Glucose is sent to blood. Lactate from blood converted into glucose. Protein broken down into AA. In muscle, protein turns into AA, which is turned into BCKA, which is turned into ketone bodies and glucose. Alanine from muscle also used for glucose production. Glutamine from muscle converted into alanine.
Effect of first messenger in insulin signalling cascade
RTK receptor autophosphorylates
What is the cause of insulin resistance
A faulty RTK receptor
What does the RTK receptor do
Phosphorylated IRS1 (insulin receptor substrate 1) using an ATP in the process
What does the effect of the RTK receptor have downstream (effect of the effect)?
Binds to protein kinase (PI3K), activating it. This allows it to phosphorylate PIP2 (phosphatidylinositol diphosphate) into PIP3 (phosphatidylinositol triphosphate), spending an ATP in the process.
What is PIP3 and what happens when it accumulates
Lipid species found in membranes, with the specific role as a 2nd messenger. It attaches to inactive protein kinase b and attaches to phospholipid-dependent kinase 1. This activates protein kinase b and it is released from PIP3. This is the final sequence of the membrane-bound reactions.
What are the two roles of protein kinase b related to insulin?
Phosphorylates glycogen synthase kinase 3 to inactivate it, and phosphorylates phosphodiesterase to activate it, thereby breaking down cAMP into AMP, leading to down-regulation of glycogen breakdown.
What is the second messenger of the insulin signalling cascade?
PIP2
How does adrenaline glycolysis in muscle affected
Increased
How does adrenaline affect glyconeogenesis in muscle
Increased
How does adrenaline affect glycogenolysis in liver
No response
How does adrenaline affect gluconeogenesis
Decrease
How does adrenaline affect glucose uptake in muscle
Increased
How does adrenaline affect lipolysis
Increase
How does adrenaline affect fatty acid biosynthesis
Decrease
