The many organelles of the cell are suspended in a watery medium called the cytoplasm—the location of many of the cell’s chemical reactions. The cytoplasm includes everything within the plasma membrane except the nucleus. The cell membrane surrounds the cytoplasm at the cell’s surface; everything within the nuclear membrane (or envelope) is called the nucleoplasm. (For more about the nucleus, see below.) Cytosol is the liquid medium of the cytoplasm. If you take out all the organelles and the other components (the insoluble nonmembrane structures), you would have the fluid inside the cell, or cytosol.