In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function.The name organelle comes from the idea that these structures are parts of cells, as organs are to the body, hence organelle, the suffix -elle being a diminutive.Organelles are either separately enclosed within their own lipid bilayers (also called membrane-bound organelles) or …

The vault or vault cytoplasmic ribonucleoprotein is a eukaryotic organelle whose function is not yet fully understood. Discovered and isolated by Nancy Kedersha and Leonard Rome in 1986, vaults are cytoplasmic organelles which, when negative-stained and viewed under an electron microscope, resemble the arches of a cathedral's vaulted ceiling, with 39-fold (or D 39d) …

The University of Vermont (UVM), officially the University of Vermont and State Agricultural College, is a public land-grant research university in Burlington, Vermont.It was founded in 1791 and is among the oldest universities in the United States as it was the fifth institution of higher education established in the New England region of the U.S. northeast.

In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, meaning kernel or seed) is a membrane-bound organelle found in eukaryotic cells.Eukaryotes usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many.The main structures making up the nucleus are the nuclear …

The cilium, plural cilia (from Latin 'eyelash') is a membrane-bound organelle found on most types of cell, and certain microorganisms known as ciliates. Cilia are absent in bacteria and archaea.The cilium has the shape of a slender threadlike projection that extends from the surface of the much larger cell body. Eukaryotic flagella found on sperm cells and many protozoans …

A biological membrane, biomembrane or cell membrane is a selectively permeable membrane that separates cell from the external environment or creates intracellular compartments.Biological membranes, in the form of eukaryotic cell membranes, consist of a phospholipid bilayer with embedded, integral and peripheral proteins used in communication and transportation of …

The Rho family of GTPases is a family of small (~21 kDa) signaling G proteins, and is a subfamily of the Ras superfamily.The members of the Rho GTPase family have been shown to regulate many aspects of intracellular actin dynamics, and are found in all eukaryotic kingdoms, including yeasts and some plants. Three members of the family have been studied in detail: Cdc42, …

A biological system is a complex network which connects several biologically relevant entities. Biological organization spans several scales and are determined based different structures depending on what the system is. Examples of biological systems at the macro scale are populations of organisms.On the organ and tissue scale in mammals and other animals, …

The acrosome is an organelle that develops over the anterior (front) half of the head in the spermatozoa (sperm cells) of many animals including humans. It is a cap-like structure derived from the Golgi apparatus.In Eutherian mammals the acrosome contains degradative enzymes (including hyaluronidase and acrosin). These enzymes break down the outer membrane of the …

Ein Organell (Diminutiv zu Organ, also „Orgänchen“) ist ein strukturell abgrenzbarer Bereich einer Zelle mit einer besonderen Funktion. Die Definition ist uneinheitlich: Manche Autoren bezeichnen nur Strukturen mit Membran als Organellen, also beispielsweise Zellkern, Mitochondrien, Plastiden (mit Chloroplasten), den Golgi-Apparat und das Endoplasmatische Retikulum.