Endosomes

Part of speech: noun

Definitions

1. A type of membrane-bound compartment within a cell that plays a crucial role in the transport and processing of molecules after they are engulfed
2. Structures involved in endocytosis which facilitate the internalization and recycling of proteins and lipids, helping to regulate cellular pathways
3. Organelles that participate in cellular trafficking and sorting, functioning in the degradation of materials intracellularly after taking in extracellular substances

Etymology: "Endosomes" is the plural of "endosome", a noun for the membrane-bound compartments inside a cell that sort and carry material taken in from outside. The word is built from two parts: "endo-", from Greek "endon", meaning "within", and "-some", from Greek "soma", meaning "body". Put together, the name describes a small body lying inside the cell. The "-some" element is the same one found in "chromosome" and "ribosome", where it likewise names a discrete body within a cell. Biologists coined these formations from classical Greek roots when they needed names for newly observed structures, so "endosome" is a modern scientific term rather than something ancient writers used.

Synonyms: vesicles, membrane-bound organelles