Regulation of Glycolysis Flashcards
Why do e need to regulate glycolysis. Be specific, 3 answers. 1 over arching theme (purple)
What mechanisms do cells use to control biochemical pathways that are thermodynamically favorable. (Need to know 5, 7 total.)
Explain an example with the liver, of how tissue specific enzyme expression works. And why it’s different in the liver than the rest of the body at all.
Give an example of control of enzyme levels using HIF-1. Explain why it functions as it does.
Give an example of how allosteric control works using ATCase.
Give an example of covalent modification of proteins using phosphorylation(s).
Give an example of hormone-induced signaling effect on enzymatic activity using insulin.
Why does regulation of biochemical pathways tend to occur at reactions far from equilibrium?
What is the Gibbs free energy equation (concentration dependent).
What are the three reactions in glycolysis that are very far from equilibrium?
Understand this.
Non-liver hexokinases are inhibited by what? Why does this make sense? (Why not in the liver?)
If there is a ton of energy in the cell (G6P) we don’t need to be making more right now. So it makes sense to have product inhibition.
How is Phosphofructokinase regulated? What step is it?
ATP shouldn’t change very much compared to ADP and AMP concentration. So by comparing levels of ATP relative to ADP and AMP, it can regulate when we need to make more.
Explain how Fructose-2,6-bisphosphate is considered a “turbocharger”, and how it’s regulates itself.
Explain how concentration of 1. F-2,6-BP affects activity, and how 2. ATP affects activity.
- The more of it there is, the more active it becomes.
- Need some to act as a substrate, but it’s still also an inhibitor so can’t have too much otherwise you lose activity.
Explain how pyruvate kinase is regulated.
How does glucose differ from fructose regarding metabolism in the liver?
Fructose is used by liver whenever, doesn’t have nearly as much regulation. Does NOT stimulate insulin.
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