Integration of Metabolism Flashcards
What are the products of pyruvate?
- alanine
- OAA
- acetyl CoA
- Lactate
When is gluconeogenesis activated?
- fasting
- exercise
What promotes gluconeogenesis to protect against hypoglycemia?
Glucagon
What does gluconeogensis create?
new sugar
What does gluconeogensis provide glucose for?
- brain
- muscles
- erythrocytes
What are the precursors of gluconeogensis?
- pyruvate
- lactate
- glycerol
- alanine
- aspartate
Where does gluconeogensis occur?
- mainly in liver
- small extent in renal cortex
What are the precursors of acetyl CoA?
- pyruvate
- AA
- FA
Where can acetyl CoA be used?
- TCA
- ketone bodies
- sterols
- FAs
What cycles is AA metabolism important in?
- Cori cycle
- glucose-alanine cycle
Is the glucose-alanine cycle active during the fed or fasting state?
prolonged fasting
Which AA is normally present in the blood in much higher concentrations than other AAs?
Glutamine
What AA serves as a source of amino groups in a variety of biosynthetic reactions?
Glutamine
Excess of what can lead to metabolic acidosis?
ketone bodies in blood
Glutamine and metabolic acidosis
increase in glutamine processing by the kidneys
What does free ammonia react with during metabolic acidosis?
form salts and excreted
What process is occurring with carbs in the fed state?
- glycogen synthesis in liver and muscle
- glycerol and FAs- TAGs
Where are lipids stored during the fed state?
- chylomicrons (TAG)
- AT-TAG storage
What occurs with the proteins in the well fed state?
- various tissues for protein synthesis
- hemes and other cofactors
- degraded for small amount of energy
What occurs with the insulin and blood glucose levels during the early fasting state?
Decreasing
What occurs with the glucagon levels during the early fasting state?
increasing
What occurs with glycogenolysis during the early fasting state?
increasing
What occurs with the gluconeogensis during the early fasting state?
increasing
What happens to glycogen in the fasting state (after 30h)?
liver glycogen depleted
What generates the glucose during the fasting state (after 30h)?
gluconeogensis generates all
What is the source of glucose in the fasting state (after 30h)?
TAG- glycerol
What stimulates the protein breakdown in the fasting state (after 30h)?
Glucagon
What is generated during the fasting state (after 30h)?
ammonia
What cycle is activated in the fasting state (30h)?
Urea cycle in liver
What is the source of energy in starvation?
FAs and AT
What happens with ketone bodies during starvation?
- increase in blood
- brain uses
What happens with gluconeogenesis during starvation?
occurs at lower rate in liver
What occurs during phase I of glucose homeostasis?
- exogenous origin of glucose
- all tissues use
- brain = glucose
What occurs during phase II of glucose homeostasis?
- glycogen and hepatic gluconeogenesis = origin
- all muscles except liver use
- brain = glucose
What occurs during phase III of glucose homeostasis?
- hepatic gluconeogensis, glycogen origin
- all muscles except liver use
- brain = glucose
What occurs during phase IV of glucose homeostasis?
- gluconeogenesis, hepatic and renal origin
- Brain, RBCs, renal medulla use
- brain = glucose, ketone bodies
What occurs during phase V of glucose homeostasis?
- gluconeogenesis, hepatic and renal origin
- Brain at diminished rate, RBCs, renal medulla use
- brain = ketone bodies
