HUMAN PHYSIOLOGY
BREATHING AND RESPIRATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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If O2 is lacking, they cannot lose electrons
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If O2 is lacking, they cannot gain electrons
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If O2 is lacking, they cannot lose all of their electrons
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If O2 is lacking, they lose to many electrons
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Detailed explanation-1: -Part of this is considered an aerobic pathway (oxygen-requiring) because the NADH and FADH2 produced must transfer their electrons to the next pathway in the system, which will use oxygen. If oxygen is not present, this transfer does not occur.
Detailed explanation-2: -NADH and FADH2 molecules formed during Glycolysis and Krebs Cycle carry their electrons to the electron transport chain. The electron transport chain creates a proton gradient that ultimately leads to the production of a large amount of ATP.
Detailed explanation-3: -Oxygen is the terminal electron acceptor in the mitochondrial electron transport chain and therefore is required for the generation of energy through oxidative phosphorylation.
Detailed explanation-4: -NADH has many fewer uses in the cell than ATP. It is normally converted into ATP in the mitochondrial electron transport chain if oxygen is present. If no oxygen is present, then NADH builds up and the cell can run completely out of NAD.
Detailed explanation-5: -When no oxygen is present, the electron transport chain can’t run because there is no oxygen to act as the final electron acceptor. This means that the ETC will not be accepting electrons from NADH as its source of power, so NAD+ will not be regenerated.