Worlds of David Darling
Encyclopedia of Science
   
Home > Encyclopedia of Science

cytoplasm





cytoplasm
A transmission electron micrograph of the cytoplasm of a plant cell. M = mitochondrion; V = vacuole; G = Golgi apparatus ; W = cell wall; P = plastid; ER = endoplasmic reticulum. Image credit: Donald Dandforth Plant Science Center
The jelly-like matrix that surrounds the nucleus of a cell and is bounded by the cell membrane. It includes the organelles of the cell as well as the sugars, amino acids, and proteins that the cell uses for growth and reproduction. Cytoplasm was formerly referred to as protoplasm. The portion of the cytoplasm that lies outside organelles and includes other insoluble cellular components is called cytosol.

Seen through an electron microscope, the cytoplasm appears as a three-dimensional lattice of thin protein-rich strands known as the microtrabecular lattice (MTL), which serves to interconnect and support the other solid structures in the cytoplasm. Cytoplasm is also the home of the cytoskeleton, a network of cytoplasmic filaments responsible for the movement of the cell and which gives the cell its shape.

The cytoplasm contains dissolved nutrients and salts, helps dissolve waste products, and is an excellent conductor of electricity. It facilitates the movement of materials around the cell by moving and churning through a process called cytoplasmic streaming. The nucleus often flows with the cytoplasm, changing shape as it moves.


Related category

   • CELL BIOLOGY