The framework of myosin and kinesin motion during the flexing of a muscle has proven to be erroneous. The Phosphorus emission does not create the propelling motion and this has been proven on 2015. Thus, the whole theory falls apart and no current theories exist to compensate for the shortcoming. Do I have to learn something that I know to be false? Will AAMC test us on things that are in a scientific grey area?
That's a good question and something I actually discussed with my professor when taking Cell Biology. The short answer is: no. The long answer as it pertains to your question is that you'll need to understand 2 major things: 1) Calcium binds to troponin, shifting tropomyosin over to free up the myosin binding site on actin, allowing myosin to attach to actin. 2) ATP is required for myosin to detach from actin (the way I remember this is that when someone dies, "rigor mortis" ,which means stiffness of death in Latin, sets in due to no ATP being available and thus myosin does not detach from actin). These two points account for nearly all of the AAMC practice questions on muscle contraction (I would say all of them, but I'm sure there's an exception or two). As a general rule for your "scientific grey area" question: if you can only find it in research articles and not in any general source, test prep or textbook for a class, it won't be on the MCAT. There always could be an exception, so if you find one let me know so I can make a video on it.
Good question! Unfortunately, it depends on the question. The AAMC problems I've seen-and there aren't that many on specific gravity-keep everything else in specific gravity, so you for those you could just leave it as if it were a direct measure of gravity. For anything that requires you to compare specific gravity to a density written out in units, you would probably need to convert the specific gravity density to the appropriate units.
One application of it is the percent submerged. ie if a ball has a specific gravity of 0.5 and its placed on water, then half of it will be submerged and half will be above the waterline.
