A cell consists of a mass of protoplasm, generally enclosed in a cell membrane, and containing a nucleus and nucleolus.
No breathing organs are seen, because osmosis of oxygen and carbon dioxide may take place anywhere through the cell membrane.
The cell membrane of this class contains no pure cellulose, but a modification called fungus cellulose.
The outer covering, or cell membrane, of the globular egg remains undivided.
cell membrane n.
The semipermeable membrane that encloses the cytoplasm of a cell. Also called cytomembrane, plasmalemma, plasma membrane.
|cell membrane |
The thin membrane that forms the outer surface of the protoplasm of a cell and regulates the passage of materials in and out of the cell. It is made up of proteins and lipids and often contains molecular receptors. The membranes of organelles within the cell are made of the same basic material as the cell membrane. In plant cells, the cell membrane is surrounded by a rigid cell wall. Also called plasma membrane. Compare cell wall. See more at cell.