Posted: Aug 05, 2020 4:46 am
Cito di Pense wrote:Why is directional force generated? If it wasn't, it wouidn't work, would it? It's the underlying structure that leads to the direction. Why ask why?
Well isn't that a great attitude for a forum dedicated to rational inquiry. Let's just not ask why, because what's the point in knowledge anyway.
Cito di Pense wrote:Nobody can just pour this knowledge into your head.
No, indeed, in my experience it comes from asking questions and discussing the answers.
campermon wrote:Jbags wrote:
What I don't understand is point d. - how does this release of chemical energy lead to mechanical work? ...
Work / energy / heat are the same thing. A good place to start is here; https://en.wikipedia.org/wiki/Work_(thermodynamics)
Thanks for this. Actually, this points to an example I understand of how chemical energy leads to mechanical work.
> Combustion of hydrocarbons leads to chemical energy stored on molecular bonds being released as thermal energy.
> The thermal energy heats up gases confined in a contained space (cylinder) increasing pressure in all directions
> The cylinder is designed in a way that it can only expand in one direction - by movement of a piston head - so movement occurs in a specific direction.
There are only a few simple causal links required to get from start to finish - molecular bond breaks releasing thermal energy, hot gases expand, expansion of gas is funneled in a specific direction.
I can't create the similar causal chain for the use of ATP in muscles. As far as I can tell, it is not the same as combustion - pressure is not generated by heating a medium up and then funneling increased pressure in a specific direction.
Rather, the 'shape' of the myosin molecule changes in a specific direction - but why is that? Is the myosin molecule like a rubber band, that's stretched by the binding of ATP and released by the breaking of these bonds? If so, why does it 'snap back' to a previous shape?
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For the record - I appreciate anyone willing to help me on my journey to understanding; even if I still have a way to go, every little helps.