Why isn fluid collected in the active site of an enzyme?
This would be because of the relative sizes of enzymes and water molecules. Though enzymes, being generally large, globular proteins, *are* much larger than water molecules, the water does not behave as a “fluid” around the enzyme. It’s like the difference between diving into a swimming pool or a ball-pool: to the enzyme, the water molecules are like the plastic balls in a ball pool, not like a fluid. As for the NaCl analogy, the only thing I can think of is the “hydration sphere”/ The reason why NaCl dissolves in water at room temperature (while you’d have to heat it to 801oC to melt it) is because of the polarity of water molecules. In H2O, the oxygen is slightly more “greedy” for the electrons of the covalent H-O bond, and so the electrons are kept closer to the O end: this makes the O *slightly* -ve and the Hs *slightly* +ve. Therefore, when NaCl is put into water, the +ve Na attracts the -ve O end of water, and the -ve Cl attracts the +ve H end. The Na+ ion therefore ends-up surro
