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Comment by janpmz | Hacker News Reader

Mitochondria are ancient bacteria that merged into the eukaryotic cell, accordinga to a theroy. They have a distinct DNA from the rest of the human body and are inherited via the mother. The amount of mitochondria can change, if you exercise more and eat less sugar, the number of mitochondria in your body grows!

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> The amount of mitochondria can change, if you exercise more and eat less sugar, the number of mitochondria in your body grows!

Why is that and what effect does it have?

Mitochondria are involved in aerobic energy production in the cell, using O2 (oxygen) and some energy substrate to produce ATP (adenosyne tri-phosphate), the "energy currency of the cell".

"exercise more" means "higher energy needs", and growing the amount of mitochondria would be adaptive.

"eat less sugar" means less anaerobic energy production, I guess. Thus more aerobic energy production in exchange.

Interesting - I guess there is some sort of balance there, given the radical biochemistry that is seen with Mitochondria. “The more [mitochondria] the merrier” …?

The more the merrier, yes. I’m an amateur road cyclist and most of my training is spent in the lower heart-rate “zones” trying to train my mitochondria. The theory is that for endurance sports the key variable is your mitochondria’s capacity to use oxygen and fuel to produce ATP.

Further, if the mitochondria is being asked to make more ATP than it can aerobically, then it will skip the final respiratory step and respire without oxygen (anaerobically). This causes a build up of lactate in the cells that is not tolerated above a certain level, I believe due to it raising acidity levels in the cell.

You’ll often hear athletes and coaches talk about lactate threshold and Functional Threshold Power (FTP). This is all to do with mitochondria function.

If I'm rowing for 20-30 minutes in a HF range of 150-160, that should fall into your parameters, right? This is a very interesting fact - I have been sedentary for a couple of years and I'm fighting a kind of fatigue. Maybe this is a way to work against the symptoms. Do you know of a way to tell if the effects are taking hold?

You’ll know! I’ve been doing a lot of “base” training over the last few months and I feel a lot faster. And my Strava data agrees

It also applies selective pressure on your population of mitochondria which can reduce the prevalence of deleterious mutations and make them more efficient on a population basis.

I also understand that mitochondria is affected by Low Level Laser Therapy (LLLT) [1][2].

[1] https://www.medcentral.com/pain/chronic/low-level-laser-ther...

[2] https://weberlasersystems.com/collections/books

that theory doesn't seem to encompass all that is know.

> Wallace notes: “The mitochondrial theory of aging holds that as we live and produce ATP, our mitochondria generate oxygen free radicals that inexorably attack our mitochondria and mutate our mitochondrial DNA.”1

if aging is killing the mitochondria, why then the mother passing mitochondria to the offspring give them a blank state if they got dna-damaged mitochondria to begin with?

Could you please expand your comment for people, like me, who doesn't have a good knowledge of medicine and/or biology?

Also, are you saying that LLLT fails on its claims? If so, could you please reference some study to follow the topic.

The mitochondria that mothers pass down are from a special group of cells that already existed when the mother was born and they are kept in a special, protected state that minimizes damage.

Wouldn't they still degrade every generation? I'd expect them to be created new, like new spermatozoa that are born with long telomeres.

If that was true then how would any other single celled organism be able to exist?

Plot twist: Earth life is slowly running out of mitochondria.

It reminds me of the central plot of an old game called Parasite Eve (1997). I don't know if anyone still knows it.

https://en.wikipedia.org/wiki/Parasite_Eve_(video_game)

ah the good old days.

Indeed : ]

Technically, if you are obese wouldn't you have more cells, and therefore a higher total number of mitochondria?

Silly example of course, but what is the obvious benefit of having a higher number of mitochondria in your body?

I believe that generally when you become obese your fat cells are just becoming enlarged

Hey! How dare you, I resemble that remark!

My understanding is that only happens to a point, then new fat cells are generated, which will then just deflate/inflate when weight is lost and regained again. I think it's one of the reasons that losing fat is so much harder than gaining fat.

The obvious benefit is having a greater ability to produce cellular energy, in principle also having the feeling and experience of having more energy. When you gain weight your overall energy expenditure does go up a lot, but not really in a useful way- you are just supporting the maintenance and physical movement of the extra weight. It’s more useful to think of energy expenditure in proportion to bodyweight.

They tend to concentrate in muscle cells, so fat cells themselves will not help much

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