Do mitochondria really provide a lot of energy?

[molbol2000]

There is a contradiction here. If the mitochondria is energy efficient, then the aerobic regimen should provide maximum power. However, high-intensity exercise provided by an anaerobic regimen based on the Cori cycle

[Endy0816]

4 hours ago, molbol2000 said:

There is a contradiction here. If the mitochondria is energy efficient, then the aerobic regimen should provide maximum power. However, high-intensity exercise provided by an anaerobic regimen based on the Cori cycle

I think the problem is the availability of oxygen though they do make much more ATP.

Edit:

This link talks about it in good detail:

http://chemistry.elmhurst.edu/vchembook/615coricycle.html

Edited October 14, 2020 by Endy0816

[molbol2000]

On 10/14/2020 at 1:28 PM, Endy0816 said:

I think the problem is the availability of oxygen though they do make much more ATP.

No, it's impossible.
For example, the sprinter runs first 100 meters without deep breathing and his speed maximal. Then, when deep breathing arise, his speed becoming lower.

Thus, the more oxygen is consumed, the greater the power drop

 

[CharonY]

You are confusing different aspects here, and one issue is the way you think or define "maximum power". You have to think about what it means (or what you mean with it).

Aerobic breakdown provides the most energy per metabolized molecule. It provides energy from glycolysis as well as via the respiratory chain (i.e. oxidative phosphorylation). Anaerobic glycolysis only takes the first part and misses out on the latter. Therefore aerobic pathways yield maximum power per glucose, whereas the anaerobic pathway does not.  However, what the body does is ramp up glycolysis for short term energy generation and instead of further going down the oxidative phosphorylation, they miss out on that part (as oxygen becomes limited) and end up with lactate. I.e. the increase in energy is by increasing the front reaction, rather than having a more effective pathway.

There is also the phosphagen system that can yield energy without oxygen, but again it is not as efficient as is used for short-term ATP generation. So in other words, for short bursts, oxygen becomes rate limiting, but as a whole provides more energy per glucose.

[molbol2000]

3 hours ago, CharonY said:

You are confusing different aspects here, and one issue is the way you think or define "maximum power". You have to think about what it means (or what you mean with it).

as in technique: maximum strength per unit of time

3 hours ago, CharonY said:

Aerobic breakdown provides the most energy per metabolized molecule. It provides energy from glycolysis as well as via the respiratory chain (i.e. oxidative phosphorylation). Anaerobic glycolysis only takes the first part and misses out on the latter. Therefore aerobic pathways yield maximum power per glucose, whereas the anaerobic pathway does not. 

This is not a correct description. Apart from the possibility of lipolysis, in any case, everything starts with glycolysis, but at the stage of pyruvic acid, the process can turn into the citric acid cycle or the Cori cycle. In the second case, the substrate will be renewable, from the liver through the blood, glucose enters the cell again

3 hours ago, CharonY said:

However, what the body does is ramp up glycolysis for short term energy generation and instead of further going down the oxidative phosphorylation, they miss out on that part (as oxygen becomes limited) and end up with lactate. I.e. the increase in energy is by increasing the front reaction, rather than having a more effective pathway.

This was just discussed above. This does not correspond to reality, the example of a sprinter confirms this. Oxygen supply, on the contrary, reduces power

Edited October 15, 2020 by molbol2000

[CharonY]

4 hours ago, molbol2000 said:

as in technique: maximum strength per unit of time

Still not enough information. For short bursts, again, forgoing oxidative phosphorylation will produce more in a short amount of time. If you look at production over, say, a day, ATP will mostly be produced  via oxidative phosphorylation. 

 

4 hours ago, molbol2000 said:

This is not a correct description. Apart from the possibility of lipolysis, in any case, everything starts with glycolysis, but at the stage of pyruvic acid, the process can turn into the citric acid cycle or the Cori cycle. In the second case, the substrate will be renewable, from the liver through the blood, glucose enters the cell again

You are missing the part that there is no free energy: The Cori cycle costs 4 ATP per cycle (2 ATP are produced via glycolysis, but 6 are consumed for gluconeogenesis). So going through the whole cycle would mean a net loss of 4 ATP, or accumulation of lactate (for 2 ATP per glucose). Meanwhile full oxidation of glucose yields ~38 ATP, but is limited by available oxygen.

  

4 hours ago, molbol2000 said:

This was just discussed above. This does not correspond to reality, the example of a sprinter confirms this. Oxygen supply, on the contrary, reduces power

I think you may confuse cause and effect. Because you seem to imply that sprinters produce more energy because they stop breathing, which is backwards reasoning. Anaerobic respiration does not stop because you have oxygen. Rather, it starts if you run out of it. 

[molbol2000]

On 10/16/2020 at 7:22 AM, CharonY said:

I think you may confuse cause and effect.

There is nothing to confuse, we just have the fact: more oxigen less power. That's all.

 

On 10/16/2020 at 7:22 AM, CharonY said:

respiration does not stop because you have oxygen

100 meters of run belongs about 10 second. It is possible to run this distance  without breathing at all

and sprinters never breath intensive when they runs.

[CharonY]

If you insist in not understanding how the energy is generated, I cannot help you. However, do you realize: a) how much energy can be gained with from glucose using oxidative phosphorylation vs just the anaerobic pathway? b) how just conducting glycolysis is not sustainable and c) why therefore we need mitochondria? (as these all relate more closely to the question in title ?)

[molbol2000]

12 hours ago, CharonY said:

If you insist in not understanding how the energy is generated,

Btw we don't talk about it at all. This is another problem to explain how ATP goes from inside mitohondria to fibers and why mitohondria give it(after all, they synthesize it for themselves and not for the muscles.)

13 hours ago, CharonY said:

a) how much energy can be gained with from glucose using oxidative phosphorylation vs just the anaerobic pathway?

It seems just a manipulation. When they count it they do not account for glucose regeneration in the Cori cycle. 
that is, they compare ATP of only one cycle stroke with complete oxidation decay.

 

13 hours ago, CharonY said:

b) how just conducting glycolysis is not sustainable

I don't understand

13 hours ago, CharonY said:

why therefore we need mitochondria?

Nobody really knows this. It is only known that these are cellular parasites, and some began to believe that these parasites eventually became symbiotic. 
True, this is extremely doubtful, because mitochondria cause significant damage and intoxication, kill cells, lead to aging, and so on.
It is also clear that they are the main consumers of oxygen.

[CharonY]

9 hours ago, molbol2000 said:

It seems just a manipulation. When they count it they do not account for glucose regeneration in the Cori cycle. 
that is, they compare ATP of only one cycle stroke with complete oxidation decay.

 

22 hours ago, CharonY said:

b) how just conducting glycolysis is not sustainable

I don't understand

You missed (again) the fact that the Cori-cycle costs energy. Each regeneration of lactate costs two more than glycolysis can provide. There is a name for it: oxygen debt. This is why after running you keep being out of breath, your body needs the oxygen to produce enough energy to get rid of the lactate. It is like taking a loan. You look at the boost of money and think great, endless cash! But you forget that you need to pay it back with interest.

9 hours ago, molbol2000 said:

Btw we don't talk about it at all. This is another problem to explain how ATP goes from inside mitohondria to fibers and why mitohondria give it(after all, they synthesize it for themselves and not for the muscles.)

 

9 hours ago, molbol2000 said:

Nobody really knows this. It is only known that these are cellular parasites, and some began to believe that these parasites eventually became symbiotic. 
True, this is extremely doubtful, because mitochondria cause significant damage and intoxication, kill cells, lead to aging, and so on.
It is also clear that they are the main consumers of oxygen.

Here is the thing, we pretty know all about this. We know which transporter move ATP across the mitochondrial membrane. It is obvious why mitochondria relinquish the energy, they do not need it, their metabolism is coupled with the host cell. We know that damages to mitochondria lead to disease and damage, and that most eukaryotic cells types need them to function. 

Listen, it is fine not to know a particular topic, even a rather common one as it may depend on how it was taught. But it is a bit silly to assume that this partially formed view is indeed the scientific state of knowledge. Mitochondria are one of the best investigated organelles due to their importance and there is an incredible amount of literature out there. So it is fine to be ignorant, but there is little excuse in wanting to stay so. 

[molbol2000]

2 hours ago, CharonY said:

You missed (again) the fact that the Cori-cycle costs energy.

this does not change what I said.

2 hours ago, CharonY said:

So it is fine to be ignorant, but there is little excuse in wanting to stay so. 

it is normal when there is critical thinking

[CharonY]

2 hours ago, molbol2000 said:

this does not change what I said.

It shows that you do not understand the purpose and energy requirements of the Cori cycle.

2 hours ago, molbol2000 said:

it is normal when there is critical thinking

Are you saying that critical thinking requires you to remain ignorant? 

[molbol2000]

5 hours ago, CharonY said:

Are you saying that critical thinking requires you to remain ignorant? 

Cautious about advertising "mitohondria is your friend" and so on.

By the way, in the next topic, the action of metformin was discussed, and again another testimony to the fact that the topic of mitochondria is mystified.
Metformin inhibits the mitochondrial respiratory chain and leads to fat burning. But if mitochondria metebilize fat, how can suppression of mitochondria burn it?

[CharonY]

12 minutes ago, molbol2000 said:

Cautious about advertising "mitohondria is your friend" and so on.

They are not our friend. They are essential. I am basically just replying to make sure that other folks are not possibly getting confused. 

[Ken Fabian]

There will be enough oxygen and energy already present as a buffer in a body to run for ten seconds without breathing. You will need to catch your breath after. The oxygen you take in now takes time to reach hard working muscles but you have enough reserve to cope with that.

[molbol2000]

3 minutes ago, CharonY said:

They are not our friend. They are essential. I am basically just replying to make sure that other folks are not possibly getting confused. 

I mean that nowadays a lot of advertising of this kind is being thrown into the mass media

3 minutes ago, CharonY said:

They are essential.

The details are important here. Yes, they can trigger cell-killing processes if they don't like something, so we have to please them.
But this is conceptually incorrect. It is clear that tissues can do without them, there are glycolytic fibers that do without them. The brain doesn't use them directly either.

3 minutes ago, Ken Fabian said:

here will be enough oxygen and energy already present as a buffer in a body to run for ten seconds without breathing. You will need to catch your breath after. The oxygen you take in now takes time to reach hard working muscles but you have enough reserve to cope with that.

in sports medicine it is believed that sprinters mainly use anaerobic glycolysis

I also paid attention to the fact that old people have severe shortness of breath when performing elementary movements. This can be explained by the fact that their breathing is ineffective and oxygen is poorly delivered. But then why should they inhale often, because in the lungs it is still there? It is more logical to explain this precisely by the fact that there is an overabundance of mitochondria in their tissues

In addition, outside the cellular plasma, the immune system kills mitochondria as a foreign material.

How does the activity of mitochondria differ from other bacterial cell parasites? Don't they eat pyruvate and synthesize ATP?

[CharonY]

1 minute ago, molbol2000 said:

mean that nowadays a lot of advertising of this kind is being thrown into the mass media

*Sigh* if all your information you is from the media it may be the reason you are confused. Textbooks are what you need to check out how our energy metabolism works.

There are specialized cells that use glycolysis predominantly but again, they require the help of other tissue to stay alive. Look what you are doing here is basically what you accuse media to do: propagate false information. On a topic that is extremely basic, no less.

3 minutes ago, molbol2000 said:

The brain doesn't use them directly either.

Why, do you think then is the brain so highly dependent on oxygen? Another part you do not seem to understand is that our body acts in concert. Parts of it can do anaerobic fermentation, but then requires other tissues to support them, which do oxidative phosphorylation. It is one of the perks of being multicellular, the ability to have specialized cells. Parts of the metabolism can be shuffled between cells, where intermediates are exchanged so that the whole process is not limited to a singular cell. This is also the case for the brain where e.g. certain cells for example do more NADH shuffling than other cell types. But as a whole the brain is powered by oxidative phosphorylation. Similar to muscle cells the glycolys to ox-phos ratio can be temporary out of whack, but it is then balanced out with the help of mitochondrial actions. Saying that mitochondria is taking us hostage is basically like saying that the heart is a useless organ. We need to treat it nicely or it will give out and kill us by depriving us of nutrients and oxygen, that bastard.

 

[molbol2000]

3 minutes ago, CharonY said:

Why, do you think then is the brain so highly dependent on oxygen?

I think, mitochondria appear in additional brain tissues, which act on signaling pathways and trigger apaptosis in critical situations.
This is just a hypothesis

4 minutes ago, CharonY said:

Another part you do not seem to understand is that our body acts in concert

In general, mitochondria are associated with the body of carnivores. It is conceptually that this seems to be the key to solving the problem.

[iNow]

4 minutes ago, molbol2000 said:

This is just a hypothesis

You misspelled WAG

6 minutes ago, molbol2000 said:

In general, mitochondria are associated with the body of carnivores.

This comment is a joke, but this isn’t a comedy forum. 

[molbol2000]

26 minutes ago, iNow said:

This comment is a joke, but this isn’t a comedy forum.

Where am I wrong? If the question of conceptual necessity is raised, then this is exactly the case. Mitochondria are needed to feed on meat and fat. Eating carbohydrates is, in principle, possible without this (it does not matter that this does not happen in reality, conceptually)

it is believed that only the mitochondria can use fat as an energy substrate. Predators use it

it may even be that this issue is related to ideology, therefore there are so many ambiguities

35 minutes ago, CharonY said:

But as a whole the brain is powered by oxidative phosphorylation.

If it so, why brain can not use a fat as substrate of energy?

40 minutes ago, CharonY said:

Saying that mitochondria is taking us hostage is basically like saying that the heart is a useless organ.

This is a bad analogy, by the way. Oxygen delivery is not the only function of the circulatory system.

The accumulation of fat itself has something to do with it. As a rule, predators are more prone to this than herbivores, and omnivores are especially active in gaining fat, and the leaders here are pigs and humans (and they are also physiologically similar)

this is apparently due to the fact that carbohydrates in this body are easily converted into fat

Edited October 19, 2020 by molbol2000

[iNow]

1 hour ago, molbol2000 said:

Where am I wrong?

You mean other than the numerous unaddressed ways already shared with you above?

1 hour ago, molbol2000 said:

it may even be that this issue is related to ideology, therefore there are so many ambiguities

Nope 

Edited October 19, 2020 by iNow

[molbol2000]

4 minutes ago, iNow said:

Nope 

I can explain if you want

6 minutes ago, iNow said:

the numerous unaddressed ways already shared with you above?

If I spoke to the wall, they would be even more ineffectual

[iNow]

16 hours ago, molbol2000 said:

I can explain if you want

No thanks