Glycolysis and Gluconeogenesis- Bikman Flashcards
When is insulin high?
After a meal, anticipating a meal, waking up
What does insulin do?
Decreases glucose, ketones, and fat in the bloodstream
What does glucagon do?
Increases glucose, ketonse, and fat in the bloodstream
What type of cell does not have glucagon receptors?
Myocytes - aka muscle cells
Which enzymes are irreversible in glycolysis?
Hexokinase or Glucokinase
PFK-1
Pyruvate Kinase
Which enzymes in glycolysis use ATP?
Hexokinase or Glucokinase
PFK-1
Which enzymes in glycolysis create NADH?
Glyceraldehyde 3 Phosphate Dehydrogenase
Which enzymes in glycolysis create ATP
Phosphoglycerate Kinase
Pyruvate Kinase
Which enzyme converts pyruvate to acetyl-CoA? what does it require to do so? And what are its products?
Pyruvate Dehydrogenase
It needs NAD and CoA-SH
Its products are acetyl-CoA, NADH, and CO2
What inhibits Pyruvate Dehydrogenase?
Acetyl-CoA, NADH, and ATP
Phosphorylation by PDK (pyruvate dehydrogenase kinase) also inhibits
If ATP is high and AMP is low, what happens to glycolysis?
It inhibits glycolysis
If ATP is low and AMP is high, what happens to glycolysis?
It activates glycolysis
What is the effect of high fructose 2,6 bisphosphatate?
It activates PFK-1
What happens if pyruvate kinase (PK) is phosphorylated?
It is inhibited
What are the effects of insulin in glycolysis?
It activates PK, PFK-1, and glucokinase
What are the effects of glucagon in glycolysis?
It deactivates PK, PFK-1, and glucokinase
What is the bypass reaction for glucokinase?
G6P is converted by to glucose with glucose-6-phosphotase
What is the parallel enzyme with PFK-1 and what is the product?
PFK-2 turns G6P to fructose -2,6-bisphosphate
What is the bypass reaction for PFK-1?
F1,6BP and F2,6BP is turned back to F6P by fructose 1,6 bisphosphatase
What is the bypass reaction for pyruvate kinase?
pyruvate is converted to OAA by pyruvate carboxylase. OAA is then turned back to PEP by PEPCK
What are some derivatives of pyruvate?
lactate, alanine, cystine, glycine, serine, tryptophan
How does pyruvate become lactate?
lactate dehydrogenase uses up two NADHs. NAD is recycled back into glycolysis
What occurs in the Cori cycle?
pyruvate is converted to lactate by lactate dehydrogenase. The lactate can either go to the muscles or the heart to be converted back to pyruvate.
Why can we not get glucose from a fatty acid?
you get a net zero of carbons
