Anaerobic Respiration

[pilumnus]

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My question is concerning the anaerobic respiration of pyruvate.

Does pyruvate become LACTATE or LACTIC ACID?

Or are they synonymous?

My biochem professor went on a huge rant about how lactic acidosis is "bull****" and that anaerobic respiration would not cause a surplus of H+ ion production. Hence why I thought anaerobic respiration produces the lactate ion which would not effect pH (if anything it would raise it)

Thoughts?
Thanks in advance.

 

[EParker37]

My question is concerning the anaerobic respiration of pyruvate.

Does pyruvate become LACTATE or LACTIC ACID?

Or are they synonymous?

My biochem professor went on a huge rant about how lactic acidosis is "bull****" and that anaerobic respiration would not cause a surplus of H+ ion production. Hence why I thought anaerobic respiration produces the lactate ion which would not effect pH (if anything it would raise it)

Thoughts?
Thanks in advance.

Pyruvate is converted directly to Lactate, the anion of lactic acid, via lactate dehydrogenase.

Lactic acidosis does exist, and can be caused by many different processes. While it is true that anaerobic respiration itself does not cause a shift in pH directly, in order to balance the charge, cations have to come from somewhere, generally pyruvate production. This is what may cause the pH drop, lactate in the bloodstream is simply a potential indicator of a hypoxic cell event wherein the buffer system with LD has been saturated and is no longer functioning. This is where the name comes from. Not that the lactate itself causes the acidosis.

 

[pilumnus]

Pyruvate is converted directly to Lactate, the anion of lactic acid, via lactate dehydrogenase.

Lactic acidosis does exist, and can be caused by many different processes. While it is true that anaerobic respiration itself does not cause a shift in pH directly, in order to balance the charge, cations have to come from somewhere, generally pyruvate production. This is what may cause the pH drop, lactate in the bloodstream is simply a potential indicator of a hypoxic cell event wherein the buffer system with LH has been saturated and is no longer functioning. This is where the name comes from. Not that the lactate itself causes the acidosis.

That's what I thought. However, an AAMC practice question said an anaerobically respiring cell would produce lactate AND H+ ions. So I ended up choosing an answer the suggested partial anaerobic and aerobic respiration (H+ from ETC somehow). However, they were looking for the answer the meant full anaerobic respiration.

 

[EParker37]

That's what I thought. However, an AAMC practice question said an anaerobically respiring cell would produce lactate AND H+ ions. So I ended up choosing an answer the suggested partial anaerobic and aerobic respiration (H+ from ETC somehow). However, they were looking for the answer the meant full anaerobic respiration.

They are just simplifying the process, if you make anions, you have to also make cations in order to maintain the electro neutral state of the cell.

 

[pilumnus]

They are just simplifying the process, if you make anions, you have to also make cations in order to maintain the electro neutral state of the cell.

I read on Wikipedia that these cations are H+'s that come from the hydrolysis of ATP. Would you agree with that?

 

[EParker37]

I read on Wikipedia that these cations are H+'s that come from the hydrolysis of ATP. Would you agree with that?

That's possible, but from what I remember of the topic, generally the cations come from the production of pyruvate via lactate dehydrogenase. This level of nitty-gritty though isn't going to show up on the MCAT, if it does, it will be a part of the passage, not a question.