Eukaryotic cell anatomy

irregular network of membranes coterminous with the outer nuclear membrane in eukaryote cytoplasm that form a meshwork of tubular channels, often expanded into cisternae

A lysosome () is a membrane-bound organelle that is found in all animal cells (except red blood cells), and rarely in plant cells. There are normally hundreds of lysosomes in the cytosol, where they function as the cell's degradation center. Their primary responsibility is for catabolic degradation of proteins, polysaccharides and lipids into their respective building-block molecules: amino acids, monosaccharides, and free fatty acids. The breakdown is done by various enzymes, for example proteases, glycosidases and lipases.

The cilium (: cilia; ; in Medieval Latin and in anatomy, cilium) is a short hair-like membrane protrusion from many types of eukaryotic cell. (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 have a similar structure to motile cilia that enables swimming through liquids, but they are longer than cilia and have a different undulating motion.

A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. Each myofibril has a diameter of 1–2 micrometres. They are created during embryonic development in a process known as myogenesis.

thumb|Electron micrograph of a thin cross-section through two Chlamydomonas axonemes thumb|A simplified model of intraflagellar transport.

300px|thumb | Phagocytosis of a bacterium, showing the formation of phagosome and phagolysosome

A mitosome (also called a crypton in early literature) is a mitochondrion-related organelle (MRO) found in a variety of parasitic unicellular eukaryotes, such as members of the supergroup Excavata. The mitosome was first discovered in 1999 in Entamoeba histolytica, an intestinal parasite of humans, and mitosomes have also been identified in several species of Microsporidia and in Giardia intestinalis.

In biology, caveolae (Latin for "little caves"; singular, caveola), which are a special type of lipid raft, are small (50–100 nanometer) invaginations of the plasma membrane in the cells of many vertebrates. They are the most abundant surface feature of many vertebrate cell types, especially endothelial cells, adipocytes and embryonic notochord cells. They were originally discovered by E. Yamada in 1955.

thumb|The autophagic process is divided into five distinct stages: Initiation, phagophore nucleation, autophagosomal formation (elongation), autophagosome-lysosome fusion (autophagolysosome) and cargo degradation. An autophagosome is a spherical structure with double layer membranes. It is the key structure in macroautophagy, the intracellular degradation system for cytoplasmic contents (e.g., abnormal intracellular proteins, excess or damaged organelles, invading microorganisms). After formation, autophagosomes deliver cytoplasmic components to the lysosomes. The outer membrane of an autophag

closed part in cytosol

thumb|right|Schematic drawing of Cafeteria roenbergensis ([[Heterokonta: Bicosoecida) with two unequal (heterokont) flagella: an anterior straminipilous (with tubular tripartite mastigonemes) and a posterior smooth]] thumb|right|A chrysomonad (Heterokonta: [[Chrysophyceae) under TEM, with a smooth flagellum (1) and a long flagellum covered with mastigonemes (3)]] thumb|Two cryptomonads (Cryptophyceae) under SEM. Mastigonemes not visible.

thumb|300px|Model of the retromer heteropentameric complex (VPS26A|VPS26 in green; [[VPS35 in orange, and VPS29 in red). The retromer forms a polymeric network arc on the outside (cytoplasmic side) of the endosome tubule. Inside the tubule, the cargo receptor SORL1, forms its own network and binds protein cargo for trafficking. SORL1 connects to retromer on the outside via a transmembrane helix and a short C-terminal tail that binds VPS26. Model built based on structural data by Brett Collins and Yu Kitago.]] Retromer is a complex of proteins that has been shown to be important in recycling tr

vesicle that is part of the extracellular region