Glycolysis Review
What reactions of glycolysis are "irreversible"?
Note that reactions are irreversible in a physiological sense.
How can reactions become physiologically irreversible when enzymes catalyze fully reversible reactions, and when their catalytic mechanisms are completely reversible?
Which enzymes are involved in control?
- How are regulatory steps determined experimentally?
- Rationalize/explain the types of regulation seen in each of the three regulatory enzymes.
- How do these differing regulatory mechanisms integrate the overall pathway control?
- What is the Main regulatory enzyme (flux generating step,
first committed step)
- Note there are multiple isozymes of PK with differing regulation.
What are they?
Aldolase mechanism
- Given reactant and products, write out the mechanism
for this enzyme.
- Explain this mechanism in catalytic terms.
- Show reasonable electron movements for bond making/breaking in this mechanism
- What is the key catalytic mechanism?
- What other types of catalysis are involved?
- Label your diagram with the different catalytic types at each step.
- Draw a "Kinetic Mechanism Diagram" for this reaction.
- Correlate the kinetic and chemical mechanisms.
- Note if order of addition/release is consistant with catlytic mechanism.
Glyceraldehyde-3-P DH
- Given the substrates and catalysts, write out the mechanism
for this enzyme.
- Explain this mechanism in catalytic terms.
- Show reasonable electron movements for bond making/breaking
in this mechanism
- What is the key catalytic mechanism?
- What other types of catalysis are involved?
- Label your diagram with the different catalytic types at each step.
- Draw a "Kinetic Mechanism Diagram" for this reaction.
- Correlate the kinetic and chemical mechanisms.
- Is "NAD" order consistent with catalytic mechanism? Explain.
Review pathway energy generation:
- How many ATP equivalents are generated in the conversion of
glucose to Lactate?
- Create a chart listing the reactions, the energy products (ATP, NADH, etc.), and the ATP equivalents:
- Give a pathway for the anaerobic breakdown of fructose
to lactate, naming enzyme types and energy steps.
- What is the net energy yield for this pathway in ATP units?
- What are the main entrance/exit points of Glycolysis we
have seen thus far?
©R A Paselk
Last modified 12 November 2008
