cellular respiration question

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Piepiesuperpie

Piepiesuperpie

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Technically the kreb's cycle does not (directly) use O2, but at the same time, without O2, the kreb's cycle will not happen. If there was a question asking about which of the following uses O2, and the kreb's cycle was among the options, would it be a correct choice?
 
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Piepiesuperpie said:
Technically the kreb's cycle does not (directly) use O2, but at the same time, without O2, the kreb's cycle will not happen. If there was a question asking about which of the following uses O2, and the kreb's cycle was among the options, would it be a correct choice?
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I would say yes because it needs O2 to work but im not 100% sure.. GOOD question! 👍
 
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I would say no. All the Krebs cycle does is to generate NADH and FADH2 for the ETC. It is the ETC that uses O2 with the NADH and FADH2 to generate ATP.
 
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Krebs cycle requires oxygen. It is a way that an organism can perform aerobic respiration. If there was no oxygen available, an organism would be stuck with glycolysis and fermentation.
 
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Kreb cycle does require it, in return I will ask two questions...
1) How is carbon molecules released as the molecule is anabolize?
2) What oxidizes NADH and FADH2 back to their reduced form so they can take part in the Kreb cycle?
 
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I'm confused. I'm pretty sure I'm wrong below, but could someone clarify?

Isn't the purpose of oxygen to act as the final electron acceptor in the ETC?

In the case of anaerobic bacteria, do they still undergo the Kreb's because the purpose of oxygen is just to oxidize NADH to NAD+?

For anaerobic fermentation, wouldn't acetylaldehyde / lactate act as the final electron acceptor thus restoring NAD+ for use in glycolysis / Kreb's cycle?

So in aerobic: Glycolysis>pyruvate decarboxylation>krebs cycle>ETC and repeat

Is anaerobic just glycolysis and fermentation or is it glycolysis>pyruvate decarboxylation>krebs>fermentation to restore NAD+ and repeat?
 
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SafetyDog said:
I'm confused. I'm pretty sure I'm wrong below, but could someone clarify?

Isn't the purpose of oxygen to act as the final electron acceptor in the ETC?

In the case of anaerobic bacteria, do they still undergo the Kreb's because the purpose of oxygen is just to oxidize NADH to NAD+?

For anaerobic fermentation, wouldn't acetylaldehyde / lactate act as the final electron acceptor thus restoring NAD+ for use in glycolysis / Kreb's cycle?

So in aerobic: Glycolysis>pyruvate decarboxylation>krebs cycle>ETC and repeat

Is anaerobic just glycolysis and fermentation or is it glycolysis>pyruvate decarboxylation>krebs>fermentation to restore NAD+ and repeat?
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Kreb cycle is an aerobic process, and to your question about bacteria doing Kreb cycle ?

That is a no also, because the Kreb cycle occurs at the matrix of the mitochondria, and bacteria does not have mitochondria.

Also, lets use Lamark's theory such as "use it or lose it" where way back then, whenever the animal is aerobic it could go through Kreb and the electron transport chain. Electron transport chain needs oxygen as last electron acceptor. Maybe back 2 million years ago, the anaerobes could go through Kreb cycle, but CANNOT go through etc. Since this been going on for several centuries, the anaerobes realized that going through Kreb cycle route does not benefits them at all. So eventually they turn to fermentation.

Okay, yeah really. Y'all are overlooking this.
 
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Minion said:
Kreb cycle is an aerobic process, and to your question about bacteria doing Kreb cycle ?

That is a no also, because the Kreb cycle occurs at the matrix of the mitochondria, and bacteria does not have mitochondria.

Also, lets use Lamark's theory such as "use it or lose it" where way back then, whenever the animal is aerobic it could go through Kreb and the electron transport chain. Electron transport chain needs oxygen as last electron acceptor. Maybe back 2 million years ago, the anaerobes could go through Kreb cycle, but CANNOT go through etc. Since this been going on for several centuries, the anaerobes realized that going through Kreb cycle route does not benefits them at all. So eventually they turn to fermentation.

Okay, yeah really. Y'all are overlooking this.
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Bacteria do use the Krebs cycle. Think of mitochondria as a bacterium. It occurs in their cytosol, which is what we call the "matrix" of the mitochondria.
 
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Eugeniager said:
Bacteria have glycolysis and kreba but not ETC
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They actually have the etc as well. It's through their plasma membrane. Both of the processes are more or less the same in bacteria as in a mitochondria, but the mitochondria has an extra membrane which is explained through the endosymbiosis theory.

Not all bacteria by any means do the etc or Krebs, but some do.
 
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Eugeniager said:
How come destroyer says that they do not have ETC and only get their energy from glycolysis and krebs?
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It doesn't. It says that they don't use Krebs. But I believe this to be incorrect because plenty of sources say that they do use Krebs as well.

I know this is blasphemous, yes, but I would say to discount this particular question (158 in version 2012) from destroyer.
 
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