How is oxaloacetate regenerated at the end of the citric acid cycle?
ABy reducing fumarate with FAD
BBy oxidizing malate to make NADH
CBy splitting citrate into two halves
DBy adding coenzyme A to succinate
Answer & Solution
Correct answer: B. By oxidizing malate to make NADH
1. Water is added to fumarate during step seven, and malate is produced.
2. The last step regenerates oxaloacetate by oxidizing malate.
3. Another molecule of NADH is produced in that oxidation.
4. Regenerating oxaloacetate is what closes the loop so the cycle can accept a fresh acetyl group.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.3 Oxidation of Pyruvate and the Citric Acid Cycle_
Related questions
In type 2 diabetes the oxidation efficiency of NADH is reduced, which affects:Where does the carbon dioxide released during cellular respiration come from?The citric acid cycle is described as amphibolic because its intermediates can also be useHydrogen ions pumped by the electron transport chain accumulate in the:The mobile carrier connecting the first and second complexes to the third is:How many complexes make up the electron transport chain?Making ATP by chemiosmosis is called oxidative phosphorylation because the process involveChemiosmosis accounts for roughly what share of the ATP made during glucose catabolism?