Whether or not to send the pyruvate to the mitochondrian?

[SynapticSelf]

I hope this doesn't qualify as homework help, because I'm not in school and this is more of a general question:

After Glycolysis, Pyruvate can undergo a number of reactions. If oxygen levels are low, it is converted into lactic acid so that the NAD can gain back it's proton and continue in Glycolysis. Q) Does this conversion take place in the cytoplasm as well? (I'm guessing yes)

If there is oxygen, as I understand it, the pyruvate is shuttled off to the mitochondrian and is converted into Acetyl CoA. However, I don't believe (I may be wrong) that oxygen is required for this conversion...

So why is there a buildup of lactic acid as opposed to a buildup of Acetyl CoA? How does the cell "know" whether or not to send the pyruvate to the mitochondrian? Is this somehow governed by statistics/probability?

 

[Aaron Barnard]

Yes, the conversion of pyruvate to lactic acid does take place in the cytoplasm. The cell “knows” which pathway to send the pyruvate down based on the availability of oxygen. When oxygen levels are low, the pyruvate is converted into lactic acid, while when there is sufficient oxygen, the pyruvate is shuttled off to the mitochondrion and is converted into Acetyl CoA. This decision is governed by the balance between the two pathways and is not based on statistics or probability.

 

[ravenprp]

The decision to send pyruvate to the mitochondria is not a conscious one made by the cell. It is determined by the cellular conditions and the needs of the cell at that moment.

In the absence of oxygen, the cell will convert pyruvate into lactic acid in order to regenerate NAD and continue the process of glycolysis. This conversion takes place in the cytoplasm.

In the presence of oxygen, the cell will send pyruvate to the mitochondria to be converted into Acetyl CoA, which can then enter the Krebs cycle and produce ATP. This process is called aerobic respiration.

The buildup of lactic acid occurs when the demand for energy is high and oxygen is limited. In this situation, the cell will prioritize the production of ATP through glycolysis over the more efficient but oxygen-dependent process of aerobic respiration. This buildup of lactic acid can also occur during intense exercise when the body cannot supply enough oxygen to meet the energy demands of the muscles.

The decision to send pyruvate to the mitochondria is not based on statistics or probability, but rather on the cellular conditions and the needs of the cell at that moment. The cell has various mechanisms to sense and respond to changes in oxygen levels and energy demands, and it will prioritize the most efficient pathway for energy production based on these factors.