Cytoplasm is a homogeneous, generally clear jelly-like material that fills cells. The cytoplasm consists of cytosol and the cellular organelles, except the nucleus. The cytosol is made up of water, salts, organic molecules and many enzymes that catalyze reactions. The cytoplasm plays an important role in a cell, serving as a "molecular soup" in which the organelles are suspended and held together by a fatty membrane. It is found within the plasma membrane of a cell and surrounds the nuclear envelope and the cytoplasmic organelles.

    The insoluble constituents of the cytoplasm are organelles (such as the mitochondria, the chloroplast, peroxisomes, ribosomes), several vacuoles, cytoskeletons as well as complex membrane structures (e.g. endoplasmic reticulums or the golgi apparatus).

    While all cells possess a cytoplasm, cells from different biological domains can differ widely in the characteristics of their cytoplasms. In the animal kingdom, cytoplasm occupies nearly half the cell's volume while in plant cells, the cytoplasm occupies much less space because of the presences of vacuoles.