Term | Definition |
cell membrane | the semipermeable membrane surrounding the cytoplasm of a cell. |
cytoplasm | the material or protoplasm within a living cell, excluding the nucleus. |
nucleus | a membrane-enclosed organelle found in eukaryotic cells. Eukaryotes usually have a single nucleus |
nucleous | a small dense spherical structure in the nucleus of a cell during interphase. |
Nuclear membrane | A nuclear membrane, also known as the nuclear envelope, is the lipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells. |
endoplasmic reticulum | a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis |
ribosomes | a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins. |
mitochondria | an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers (cristae). |
golgi body | a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport. |
centriole | a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division. |
Vacuole | A cavity within the cytoplasm of a cell, surrounded by a single membrane and containing fluid, food, or metabolic waste. |
lysosome | an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane. |
peroxisomes | a small organelle that is present in the cytoplasm of many cells and that contains the reducing enzyme catalase and usually some oxidases. |
chloroplast | a plastid that contains chlorophyll and in which photosynthesis takes place |
cell wall | a rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants, it consists mainly of cellulose. |