I read in a book concerning cell biology: "Many enzymes are also greatly affected by the precise chemical environment around them." I understand that enzymes are affected by their respective environments. The book's sentence seems to indicate that different environments exist in the same cell (which then go on to affect enzymes in different ways). Now since the interior of the cell is a fluid environment and that due to random thermal motion of the molecules everything in the cell is uniformly distributed throughout the cell so only one environment will exist in the cell. The environment present anywhere in a cell will exist everywhere else in the cell (except in the membrane bounded organelles). So could someone tell me whether only one or different environments exist in a cell.