Outline the conditions that direct pyruvate toward the following:
b. Conversion to ethanol and CO₂
In what tissues or organisms is each pathway present?

Question

Outline the conditions that direct pyruvate toward the following:

b. Conversion to ethanol and CO₂

In what tissues or organisms is each pathway present?

Accepted Answer

Hi, everybody. Our next question says, what are the conditions that guide lactate dehydrogenase to convert pyruvate to lactate in which tissues or organisms does this process occur? We have four answer choices and we'll go through them one by one. But before we do that, let's just kind of think of an overview of this process to evaluate these. So when we're talking about the conversion of pyruvate to lactate, we're talking about the process of lactic acid fermentation. And when we think about this process, usually the first thing that springs to mind is that this occurs in anaerobic conditions. So that could be the environment is actually lacking in oxygen. Or when we think about our bodies, we often think about muscle tissue during vigorous exercise. Due to the high A TP demand, the muscle tissue often runs low on oxygen and the body has to switch to lactic acid fermentation to continue to provide a source of A TP. And this is because in typical cellular respiration, we have oxygen acting as that final electron acceptor. So if oxygen, oxygen is not available, N A DH builds up, recall that N A DH is generated by the process of glycolysis, it's an electron carrier that usually shuttles its electrons over to the electron transport chain to produce that high yield of a TP from cellular respiration. But if oxygen's not around and that process can't take place, we have to somehow regenerate the N AD plus that allows glycolysis to continue. So that process of fermentation generates N AD plus. So if we've got N AD plus building up and we need more N AD plus to continue glycolysis, that's conditions for fermentation. And then when we think about what kind of tissues, what kind of organisms? Well, we already talked about muscle tissue. In addition, in red blood cells recall that they have no mitochondria. So they can't do typical aerobic cellular respiration and depend on lactic acid fermentation. And then when we think about what kinds of organisms, well, of course, in humans and animals uh in the muscle and in red blood cells and then in some bacteria uh like lactic acid bacteria. So with all that in mind, our kind of overview there, let's evaluate these answer choices. So choice A says anaerobic conditions check mark there. That's correct. A high N A DH to N AD plus ratio. And that's correct. As we said, a build up of N A DH. You need this process of fermentation to regenerate N AD plus and high glycolytic activity. Same reason that's churning out N A DH. We need to regenerate the materials for it to occur. It occurs in muscle cells during intense exercise. That's correct. Red blood cells and some bacteria. So choice a everything in there is correct. If I were on a task times of the essence, I would just pick that and move on. But this is a practice problem. Let's be a little more thorough and just check out our other answer. Choices. Choice B says aerobic conditions. So that's incorrect. If there's oxygen available and cellular respiration can take place. It generates a lot more A TP and will be preferred. And then low glycolytic activity would not be correct. It says it occurs in liver cells also not correct. So choice B multiple things wrong with that and choice C anaerobic conditions. So that's correct and a low N A DH to N AD plus ratio. So again, we'd expect this when there's a high N A DH to N AD plus ratio and it says it occurs in yeast cells. But this would be incorrect because yeast cells while they do have a fermentation process, this would be ethanol, fermentation or alcohol, fermentation, converting pyruvate to ethanol rather than lactic acid. So cross that out and then finally, choice D says aerobic conditions, that's correct. It occurs in plant tissues and that will be incorrect. So, cross out choice D and again, our correct answer is in choice. A talking about the conditions for the conversion of pyruvate to lactate tissues, organisms where this occurs and we have choice. A anaerobic conditions. A high N A DH to N 80 plus ratio, high glycolytic activity occurs in muscle cells during intense exercise, red blood cells and some bacteria. See you in the next video.

Outline the conditions that direct pyruvate toward the following:
b. Conversion to ethanol and CO₂
In what tissues or organisms is each pathway present?

Verified video answer for a similar problem:

Key Concepts

Fermentation

Ethanol Production

Tissue Specificity

Outline the conditions that direct pyruvate toward the following:b. Conversion to ethanol and CO2In what tissues or organisms is each pathway present?

Verified video answer for a similar problem:

Key Concepts

Fermentation

Ethanol Production

Tissue Specificity

Outline the conditions that direct pyruvate toward the following:
b. Conversion to ethanol and CO₂
In what tissues or organisms is each pathway present?