7. Intergration of metabolism Flashcards
A young healthy individuals blood glucose is about 5 mmol. What can this rise to after large meals?
8-10 mmol/L
What are the 4 metabolic states in relation to feeding?
fed state - 3-6 hours after a meal
Post-absorptive state - from fed state until 12-18 hours after meal
Fasting state - 18 hours up to 2 days after a meal
Starvation - fully adopted state of food deprivation lasting up to several weeks
What is insulin’s antagonist
Glucagon
What are the interactions of amino acids during fed state?
will initially be stored in the liver. it can then be moved to wherever they need to be
What are the interactions of Carbohydrates during fed state?
macros absorbed from the gut. liver gets first dibs on glucose. Glucose can go to the brain from here or stay in the RBCs.
Glucose is utilised in the muscle.
If there is an over supply of glucose, the rest will be stored as TG in adipose tissue
What are the interactions of fat during fed state?
stored as chylomicrons in adipose. Some can be stored in the liver
What are the interactions of carbohydrates during post absorptive state?
glucose comes from the breakdown of glycogen in the liver. Glucose can then move to the brain, blood or muscle.
What are the interactions of fat during post absorptive state?
triglycerides in the adipose tissue is converted into glycerol and fatty acids and can then move to the liver where they are utilised.
What are the interactions of amino acids during fasting state?
Proteins in the muscle are broken down to amino acids and moved to the liver to be utilised to glucose for the brain.
What are the interactions of fat during fasting state?
triglycerols broken down to glycerol and fatty acids in the adipose. moves to liver and fatty acids are also moved to the muscle. By now the body is massively reliant on fatty acids from adipose to make glucose
What are the interactions of carbohydrates during fasting state?
Glucose to the brain and red blood cells form the liver is made through alanine, lactate = glycerol. if the brain doesn’t get enough glucose at this point then is uses ketones from the fatty acids in the liver.
Explain the Randle Cycle
the competition of glucose and fatty acids for their oxidation and uptake in muscle and adipose tissue. the cycle controls fuel selection.
What happens with the interaction between amino acids, carbs and fats during starvation state?
more fatty acids being used
More ketones being used instead of glucose for the brain.
There is a drop of 75g per day of muscle at day 3 of starvation state
what is ketogenesis
If there is high rates of fatty acid oxidation in the liver and there is an accumulation of acetyl CoA there is then a synthesis of ketone bodies.
What are the properties of ketogenesis?
Low rates of carbohydrate oxidation = low oxaloacetate = decrease in TCA cycle flux = Accumulation of acetyl CoA = synthesis of ketone bodies
