Posted: Aug 04, 2020 8:32 am
Because the atoms in molecules exert forces on each other; when the configuration changes, the forces change. Don't get lost in terminology. Stick to the basics, if that's all you can understand. You can even consider that work and energy are not really different in some philosophical way. Energy converts to work (speeding up of a car, but the work is the expansion of the gases in the cylinder on ignition). This is merely fundamental thermodynamics, and you should try to understand that before you tackle biochemistry and biophysics.
"Suffiiciently" is a bit subjective. How long are you willing to study and how do you plan to test your knowledge (or anyone else's that you come across)? You haven't said how you could be satisfied by any answers you receive. This is elementary for anyone who's studied second-year physical chemistry, which is not the endpoint of a chem degree. Nobody can just pour this knowledge into your head. What I've found about a lot of wikipedia articles is that they can stimulate your curiostity, but cannot even begin to satisfy it in the article that starts it off. A wikipedia article is not the beginning of any account, not with stuff like this.
That's specialist biophysics. You should expect to study awhile before you "understand" it. At some point, even before this, the wikipedia loses its capacity to educate the novice. Don't rely on it for deep insight when it goes this far. "Power stroke" is metaphorical in the account of myosin function - the term comes from the design of heat engines. 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?
Jbags wrote:none of the explanations I have found online seem to answer this problem sufficiently (or in a way that I can understand)
"Suffiiciently" is a bit subjective. How long are you willing to study and how do you plan to test your knowledge (or anyone else's that you come across)? You haven't said how you could be satisfied by any answers you receive. This is elementary for anyone who's studied second-year physical chemistry, which is not the endpoint of a chem degree. Nobody can just pour this knowledge into your head. What I've found about a lot of wikipedia articles is that they can stimulate your curiostity, but cannot even begin to satisfy it in the article that starts it off. A wikipedia article is not the beginning of any account, not with stuff like this.
Jbags wrote:
The section on 'crossbridge cycling' on this wikipedia page seems to be relevant, but crucially in this sentence "The myosin head then releases the inorganic phosphate and initiates a power stroke, which generates a force of 2 pN", why is the power stroke initiated? Why is a directional force generated?
That's specialist biophysics. You should expect to study awhile before you "understand" it. At some point, even before this, the wikipedia loses its capacity to educate the novice. Don't rely on it for deep insight when it goes this far. "Power stroke" is metaphorical in the account of myosin function - the term comes from the design of heat engines. 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?