Ok, so high school bio got me as far as the concept of animal cells and plants cells. Great. Putting that behind us, animal cells can then be broken down into smaller categories right? From what I can tell, they are at least broken down by species and function, but are there further categorical reductions to be made? Just as an example; red blood cells vs white blood cells (both human), how and why are they structurally different? Do their organelles differ in size, shape, number or composition? What about two red blood cells from the same person, are they structurally identical? Could all human red blood cell mitochondria be considered interchangeable? Identical? I know the cell nuclei can’t at least. I really want to stress structure here, not function. I know I just typed a lot of question marks, but I am not looking to have them all answered, just trying to convey the gist of what I am after. I think I am trying to understand the gap between the intracellular level and the atomic level.
PS. slightly unrelated; when ATP is hydrolyzed into ADP and phosphate; is the energy released by that reaction the same heat energy that our bodies radiate? Is the phosphate the same phosphate excreted in our urine? Seems like it to me but I cant find explicit confirmation.