The Citirc Acid Cycle Flashcards
Preview slide:
Per molecule of Acetyl-CoA, what does the citric acid cycle produce?
2 CO2
1 GTP/ATP
4 reduced e- carriers (carrying 4 pairs of e-)
What is the overall reaction of the citric acid cycle?
How many carbons are consumed in the citric acid cycle? What does consume mean?
What happens to ALL the electrons from the citric acid cycle?
Where does the citric acid cycle take place in the cell? Why is it localized there?
Big summary slide (definitely skip until mastery of rest of card deck)
What’s the citric acid cycle on a chemical level? What are the metabolites?
Start and end with oxaloacetate.
How do you get electrons out of acetyl-CoA and into NADH/FADH2? Hint: 3 phases.
Blue= “throwing log into a fire”
Red= “burning the log until it’s charcoal” - Still usable for energy, just in a different way now.
Yellow= “using the charcoal until you need another log”
What steps of the citric acid cycle are redox reactions?
All in blue
Explain the first step of the citric acid cycle.
Highly energetically favorable, comes from breaking thioester bond.
Citrate is prochiral-not chiral yet.
Explain the second step of the citric acid cycle.
Very sterospecific conversion to new chiral molecule.
Explain the third step of the citric acid cycle.
Forms beta-keto acid, which is so unfavorable it lets go of CO2 by itself.
6 carbon becomes 5 carbon
Explain the fourth step of the citric acid cycle.
Another decarboxylation!
TPP is used!
Goes from 5C to 4C
Explain the fifth step of the citric acid cycle.
Just like GAPDH but in a single step.
Explain the sixth step of the citric acid cycle.
FAD is hungrier than NAD+ here!
Explain the seventh step of the citric acid cycle.
Both fumarate and L-Malate have transporters on mitochondrial membrane, making them move in and out.
Explain the eighth step of the citric acid cycle.
Uses concentration ratios to push reaction.
What is the picture depicting?
The origine of all carbons associated with the Citric Acid Cycle.
Notice: all carbons are eventually replaced after 3 rounds.
Out of the 8 citric acid cycle steps, which are regulated?
1,3,4
Can you came all regulation/feedback inhibition in citric acid cycle? Pyruvate dehydrogenase complex?
Define Cataplerotic process.
What are these proceses in the citric acid cycle?
Hint:4
Define Anaplerotic process.
What are these proceses in the citric acid cycle?
Hint:5
Out of glycolysis, PDR, and Citric Acid Cycle, which produces the most energy? In what order?
There are 2 NADH made through glycolysis, how do they get to the electron transport chain?
Hint:2
Explain how Malate-aspartate shuttle works shuttling NADH?
Putting electrons into Malate outside the matrix, and shuttling Malate back into matrix to “remake” NADH
No loss in energy!
Explain how glycerophosphate shuttle works shuttling NADH?
Oxidizes NAD+, put electrons on FADH2, and send them into ETC.
You lose some energy compared to other way!
Summary Slide:
