BIO question

[299678]

Q. In regard to catabolic reactions, all of the following statements describe the purpose and significance of the citri acid cycle excepts:
a) The cycle produces reducing equivalents in the form of NADH and FADH2, for use by the ETC
b) Citric acid cycle operates in Oxidative mode.
c) Oxidation of citric acid cycle intermediate requires the presence of oxygen
d) The cycle is the main metabolic produce of CO2
e) all of the above.

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[MrBeans]

Is the answer c?

ETC requires O2, not the TCA cycle.

TCA cycle produces CO2
TCA cycle makes NADH and FADH2 for ETC
Oxidation occurs in the TCA cycle

So, I would guess the answer to be c.

 

[Maygyver]

Is the answer c?

ETC requires O2, not the TCA cycle.

TCA cycle produces CO2
TCA cycle makes NADH and FADH2 for ETC
Oxidation occurs in the TCA cycle

So, I would guess the answer to be c.

I concur.

 

[UndergradGuy7]

I would guess C, too.

Although O2 is needed in an indirect kind of way. It is not needed for the Kreb's cycle, but without it NADH2 would pile up and the cycle would have to stop. Right?

 

[MrBeans]

If O2 was not present, fermentation would kick in to turn the NADH back into NAD+ for glycolysis.

 

[predentgal]

This is tricky because krebs cycle and electron transport chain can't run anarobically, which means that they need to occur under the presenc eof oxygen. BUT LIKE undergradguy said oxygen is needed in an indirect way. It's not one of the actual reactants in the krebs cycle.

 

[dentalWorks]

answer = C

Citric acid cycle produces CO2 gas (that what we exhale), O2 (which is the final electron acceptor) is not utalized until you get to the ETC

 

[OU11BB]

C i believe as well

 

[UndergradGuy7]

If O2 was not present, fermentation would kick in to turn the NADH back into NAD+ for glycolysis.

And fermentation would make lactate/ethanol not pyruvate so the krebs cycle would not be able to continue.

 

[akeurogh]

Even though O2 is needed for the TCA cycle to occur, O2 is not the oxidizing agent in the TCA cycle. The oxidizing agent in the TCA cycle would be NAD+. Therefore the answer would be C.

O2 as an oxidizing agent occurs in the ETC.