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Halfthawed replied to vicky_molokh in 2019 regarding her question associated with External ATP Synthesiser Plausibility. Halfthawed stated:

ATP is kind of already synthesized by battery power. In fact, ATP synthase is occasionally referred to by biochemists as 'the world's smallest motor', and is powered by positive H+ ions moving across a concentration gradient. Picture below, essentially the purple ring rotates as H+ moves past it and forms ATP in the green umbrella.

Could a similar method be used to generate enough charge to power a cell phone? If so, how difficult would this be?

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    $\begingroup$ Pretty difficult to solder the wires on I reckon $\endgroup$
    – Kilisi
    Commented Sep 15, 2023 at 3:10
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    $\begingroup$ Hand crank battery chargers do exist, such as this one for sale on Amazon, and even good ones are not terribly expensive. So that yes, we can already use mitochondria to power our cell phones. (General note: we are humans. What makes humans human is their ability to design, make, and use tools.) $\endgroup$
    – AlexP
    Commented Sep 15, 2023 at 7:52
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    $\begingroup$ Mitochondria powering your cell phone, I see what you did there. $\endgroup$
    – BWFC
    Commented Sep 15, 2023 at 12:04
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    $\begingroup$ Mitochondria, the powerhouse of the cellphone! $\endgroup$
    – No Name
    Commented Sep 15, 2023 at 20:23
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    $\begingroup$ Not an answer, but related, researchers at MIT created a fuel cell that can use free sugar in the body to generate electricity with a power output of about 43uW/cm^2. While 43uW doesn't seem like much, it's enough for devices that are off most of the time and only operate intermittently. news.mit.edu/2022/glucose-fuel-cell-electricity-0512 $\endgroup$
    – user4574
    Commented Sep 17, 2023 at 4:12

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Mobile phones don't run on Adenosine Triphosphate (ATP), they run on free electrons. In order to use protons (H+ ions) to generate free electrons, you'd have to either modify ATP Synthase to produce free electrons instead of ATP, or add a mechanism that converts ATP to Adenosine Diphosphate (ADP) and generates free electrons.

Neither would be a simple proposition. We are currently barely able to even begin synthesising a protein that does anything so complex. Even predicting the shape of a folded protein is an immensely difficult task requiring lots of CPU time, and then there would be the problem of getting the free electrons to the phone.

Not to mention that compared with cells, phones are terribly energy hungry. You'd need to create an electricity-generating organ that would be bigger than a phone battery to power a phone, and you would have to feed it and deal with its wastes.

You could make an electric organ, but these generate intermittent AC, and a phone needs constant DC, so you'd need to rectify and smooth the generated current, and keep the organ fed and eliminate its wastes.

Or you could use a battery, and plug it in to a charger when it runs out of energy. That's much easier and cheaper, in both purchase price and user maintenance and R&D costs.

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    $\begingroup$ ATP is used in cells to power a proton pump which creates a charge differential across membranes. The charge differential is used to move electrons through some cellular machinery. Charge differentials are also how electronics move electrons. Q.E.D. $\endgroup$
    – stix
    Commented Sep 15, 2023 at 19:14
  • $\begingroup$ Oddly enough I m not talking about a cell phone you carry in your hand and I don't think you want to jam a battery in your back every day $\endgroup$ Commented Sep 16, 2023 at 0:33
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    $\begingroup$ @EnglishmanBob Then use a glucose-oxygen fuel cell. $\endgroup$
    – Monty Wild
    Commented Sep 16, 2023 at 1:03
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    $\begingroup$ Luckily, nature is ahead of us. There are electrotrophic microbes that can convert free electrons to ATP and live off it. Some modification would be needed to get those enzymes to run in reverse, but it's probably easier than starting from scratch. (But then there is the question of why you'd want to do this in the first place - that ATP has to come from somewhere, so you need some other power source to generate it and the whole thing just becomes a very inefficient means of power transfer.) $\endgroup$
    – N. Virgo
    Commented Sep 16, 2023 at 17:25
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Mitochondria can provide about 190 mV. Some very advanced chips already work at these voltages in laboratory setting.

There is about 190 mV difference between the interior of the mitochondria and its surroundings inside the cell (source) This difference is actively supported by the metabolism inside the mitochondria and theoretically may be usable as a power source.

The problem is, even unusual mitochondria considered "giant" (described here) are only tens of µm in size. But electronic components may even be smaller hence it is possible to envision a chip attached to mitochondria and powered by it, if we would manage to stick it across the dual membrane of mitochondria without damaging it. A chip could be a radio transmitter as well.

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  • $\begingroup$ Why get hung up on real science that most readers won't even recognise, let alone understand? If you think mitochondria might power anything, why not get on and build your world that way? If you want real physics, what has that to do with Worldbuilding? $\endgroup$ Commented Sep 15, 2023 at 19:09
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    $\begingroup$ You don't need a single mitochondrion though. You can use multiple mitochondria as pumps to create a charge gradient. The charge gradient is all you need to move electrons in a circuit. It would make more sense to use genetically engineered bacteria to produce the charge gradient, but that's more or less what mitochondria are in the first place, so... $\endgroup$
    – stix
    Commented Sep 15, 2023 at 19:16
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    $\begingroup$ You can stack like 10 x 190mV cells in series and then you are at 1.9V, which is well within the range where modern electronics can run. $\endgroup$
    – user4574
    Commented Sep 17, 2023 at 4:07
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It's a long shot, but you can use the Sodium-potassium pump

The sodium–potassium pump (sodium–potassium adenosine triphosphatase, also known as Na⁺/K⁺-ATPase, Na⁺/K⁺ pump, or sodium–potassium ATPase) is an enzyme (an electrogenic transmembrane ATPase) found in the membrane of all animal cells. It performs several functions in cell physiology.

The Na⁺/K⁺-ATPase enzyme is active (i.e. it uses energy from ATP). For every ATP molecule that the pump uses, three sodium ions are exported and two potassium ions are imported. Thus, there is a net export of a single positive charge per pump cycle.

Once you can transport charge, you can theoretically power your cell phone.

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    $\begingroup$ You'd end up with an electric organ: en.wikipedia.org/wiki/Electric_organ_(fish), but these generate intermittent AC, and phones require constant DC. You'd need some sort of rectifier and capacitor setup to smooth it out... and then you'd have to keep it fed. $\endgroup$
    – Monty Wild
    Commented Sep 15, 2023 at 5:11

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