Why must electrons from the NADH made in glycolysis be picked up again by a carrier inside the mitochondrion?
AThat NADH cannot easily enter mitochondria
BThat NADH is destroyed by oxygen at once
CThat NADH binds tightly to the GLUT proteins
DThat NADH is needed to build amino acids
Answer & Solution
Correct answer: A. That NADH cannot easily enter mitochondria
1. Glycolysis happens in the cytoplasm, so its NADH is made outside the mitochondrion.
2. That NADH cannot easily enter mitochondria.
3. Its electrons are therefore picked up again on the inside by one of two carriers.
4. The two carriers do not transport equal numbers of ions, so the choice of shuttle changes the final yield.
5. This shuttle difference is one named source of variance in the adenosine triphosphate total.
6. Oxygen does not destroy NADH, it is the eventual acceptor of the electrons NADH carries.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 7 "Cellular Respiration", section 7.4 Oxidative Phosphorylation_
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?