The electrical production of ATP

[Rugged]

Now, alittle while back (on another forum site, far, far away...) I started thinking about the potential for biomechanical suits as enhancements for their wearers in many applications (eg, combat).

 

However, the control mechanisms and general potential of this is best left for another discussion.

 

What I am here to discuss is the method to be used for transferring energy to the suit's systems;

 

With my limited knowledge of biological functions, I am aware that lone pairs of electrons are used by plants to make ATP (photosynthesis).

 

I propose that a constant electrical current from a hydrogen (or methane) fuel cell be used to create a constant and plentiful supply of ATP for the suit in question.

 

Discuss;

 

Is this possible?

 

How fast can it be done?

 

How big do the individual processing biological systems need to be? (cell sized, enzyme sized...)

 

Where is the hole in my logic?

[zyncod]

What would you do with the ATP once you got it? (I'm reserving my other objections until I hear what you have in mind)

[Rugged]

What would you do with the ATP once you got it? (I'm reserving my other objections until I hear what you have in mind)

Well, the ATP would be powering the motor functions of a biomechanical suit (equipped with fullerene muscles so they can take the use of much more extensive amounts of ATP at any one time)

[zyncod]

I suppose you could patch clamp something like a mitochondrion to inject electrons. I don't know much about fullerene muscles, but with the traditional myosin system you could control contraction by electrically-mediated release of calcium. It just seems like it would be surpassingly difficult to do, for not that much benefit over just a mechanical suit.

[Yggdrasil]

What would be the point of producing ATP? Wouldn't it be more efficient to use the electrical energy from the fuel cell directly, since there will be energy lost when producing the ATP and energy lost when converting the chemical energy stored in ATP to mechanical energy?

[Rugged]

Yeah, but that electrical energy couldn't be used for a muscular structure; it woudl require a large and "unversatile" piston-like design.

 

Besides, our bodies seem to have been doing pretty well with it for the past few thousand years, lol.

 

Do remember that they have to convert fats and sugars into ATP as well...

[Connor]

If we have the energy, somehow converting it to ATP would just cause a loss of energy. It would be more efficient to use the energy directly.

 

lone electrons are not used to create ATP. Glucose is converted into pyruvate which is converted to NADH through the krebs cycle. Next, the energy of the NADH molecules are used to create ATP by creating a photon gradient across the inner membrane of mitochondria. The energy held by this gradient is then used to make ATP by phosphorylating ADP.

 

It would not be so simple as using an electrical current

[Airmid]

Hi Rugged,

 

Your idea to make ATP is not bad at all, I'd say! Here's a very simplified description of how plants generate ATP:

There's an enzyme called ATP synthase that is embedded in a membrane. There's a pool of ADP and phosphate on one side of the membrane, and some of it stick to the enzyme. To get ATP, the ADP and phosphate must be welded together, and the cell uses a cunning plan to accomplish this. It actually creates an electric potential over the membrane, which attracts protons (H+ ions) to cross the membrane. The only spot where the protons can cross it, is through the ATP synthase enzyme. The flow of protons through the enzyme generates enough energy to weld the ADP and phosphate together.

When ATP is "used up", it gets split up again in ADP and phosphate. So it can be used again to generate new ATP.

So there you go, with some of the natural enzyme and a membrane your machine would already work! You could think of ATP synthase as a kind of energy converter: it converts electrical energy (the electrical potential) into chemical energy (ATP).

 

You also asked how fast this would work, and that's a more difficult question. The speed of the enzyme is not a problem, since enzymes typically work very fast. But of course, when the enzyme does not have a plentiful supply of ADP and phosphate, it can't do much work. Also, if there's a lot of ATP present around the enzyme, it will stop working. So your job will be to make sure the newly made ATP is transported away from the enzyme, to the place where the energy is needed, and to return the ADP and phosphate to the enzyme.

 

If you'd like more information, try to look up "ATP synthase" or "chemiosmosis".

Good luck!

 

Airmid.