The cytoplasm is the fluid portion of a cell, which contains the organelles and other structures within the cell. The cytoplasm serves as a medium for transporting substances in and out of the cell; it also provides a buffer or shock absorber for larger organelles. The membrane-bound organelles within the cytoplasm are called organelles (e.g., mitochondria), while the material that makes up the interior of a cell is called cytosol.
The functions of cytoplasm include:
- Transporting materials between other parts of the cell
- Providing a buffer or shock absorber for larger organelles
- Containing certain enzymes and receptors that control chemical reactions inside cells
- Organizing and maintaining the shape of cells
- Containing many of the cell’s structures, including ribosomes and endoplasmic reticulum