Chap 21 Flashcards
Blood glucose maintained around
4.5 mM
Blood glucose maintenance involves what?
Insulin, glucagon, and adrenaline
What does insulin signal?
That blood glucose is high
Glucogon signals what?
that blood glucose is low
When glucagon signals, what occurs?
Tissues produce glucose from glycogen, liver gluconeogenesis increase, fats oxidised to reduce use of glucose
Adrenaline released into the blood why?
To prepare muscles lungs and heart for a burst of energy
Cortisol released in response to?
Stessors ( ex: anxiety, fear, pain, infection)
What are the three actions of insulin?
Stimulates glucose uptake by muscle, activates glycogen synthase and stimulates storage of excess fuel as fat
In liver, what does insulin stimulate?
Glucose 6 Phosphate to pyruvate and pyruvate to acetyl CoA and acetyl CoA fuels FA synthesis
FA made in liver converted to what
Triacylglycerols nad transported in VLDLS to fat cells
How does glucagon increase blood glucose levels?
Stimulating glycogen breakdown in liver, and inhibits liver glycolysis and stimulates gluconeogenesis
When is adrenaline released? Where is it released from?
In a stressful situation that requires increased activity Adrenal medulla.
What are physiological effect of adrenaline?
Increase heart rate and blood pressure, and increase flow of oxygen to tissues
What are some metabolic effects of adrenaline?
In muscle and liver, stimulates conversion of glycogen to glucose
What does adrenaline stimulate in fat? What else does it stimulate and inhibit?
Fat mobilization by activating triacylglycerol lipase. Glucagon secretion and inhibits insulin secretion
What does Cortisol do?
Acts on the muscle, liver and adipose tissue to supply them with fuel
What else does cortisol do?
Slow-acting. Promotes gene expression
In adipose tissue, what does Cortisol do
Promotes release of FAs stored from TG
What does cortisol do in muscle?
Stimulates breakdown of excess protein to amino acids> they are transported to liver where they act as precursor to gluconeogenesis
What does cortisol do in liver?
Promotes gluconeogenesis by stimulating expression of the PEPCK gene.
What is the overall effect of cortisol?
Raises blood glucose levels and maintains glycogen stores
After the first day or so of starvation, what will become source of fuel for the brain?
Glucose then ketone bodies, and then if starvation continues it will be ketone bodies first and then glucose
Stores of ATP last how long
~1s
After ATP utilized, what is utilized?
Phosphocreatine
What supplements can delay fatigue?
Creatine, and sodium bicarbonate
If a cell has excess of a certain amino acid, what does it typically use to prevent diversion of more intermediary molecules from the krebs cycle
Feedback inhibition
Rate of catabolism is regulated typically by what?
Level of ATP in the cell
If ATP levels drop, what occurs in cell
Catabolism speeds up to produce more ATP
What sets the pace of respiration? This enzyme inhibited and stimulated by what?
Allosteric regulation of phosphofructokinase. Inhibited by ATP and stimulated by AMP ( derived from ADP)
