To quantify freeze drag >>> updated
|Opened on:||Sunday, January 11, 2009 - 17:58|
|Last modified:||Friday, January 6, 2012 - 19:37|
Per resolution of feedback article 100-120 http://fold.it/portal/node/809073, it is now clear that a frozen section imparts drag on the system during a global wiggle.
If a clash event imparts the repulsive force "Q" , as shown by the difference in score between equilibrium and the clash event score, then the drag imparted by a frozen section has a corresponding frictional or inertial value in the equations governing movement of the structure.
The score difference between an equilibrium and stressed state is referential in nature. That is, it does not claim to be a measure of any specific underlying variable. However, it can be directly interpreted as the summed magnitude of individual forces acting upon each residue. Similarly, as we now know via the link posted above, A segment freeze also imparts some resistance to the equation of motion, either a static force or inertial drag. These can also be represented in score units or units derived from the score unit.
I have a few related questions:
1) Is the frictional or inertial drag coefficient a constant per frozen section?
2) If constant, what is that value when expressed in units of score? That is, with what magnitude does it reduce the clash force?
3) IFF not constant, what is the governing relationship between a "freeze" event and it's corresponding residue, as a function of score?
4) Is the force exerted by the freeze/lock akin to sliding friction, and if so, what is it's threshold value, expressed in units of score, ie, what force of clash is required to over come it? w
5) If purely inertial and indeterminate prior to wiggle, can you estimate at least a ballpark idea of the magnitude (or range) that one should expect from the contribution it has on the protein's ability to move, when compared to the system at large? 5%? 10%, etc?
That might (or not) be clearer