Ergosterol

Part of speech: noun

Definitions

1. A specific sterol primarily located in fungi that contributes significantly to maintaining the structural integrity of cell membranes and is vital for numerous metabolic pathways
2. This sterol, mainly found in fungi, serves an essential function in cellular membrane composition and is important for diverse biological activities
3. A type of sterol prevalent in fungal organisms that plays a critical role in preserving the stability of cellular membranes and is indispensable for various metabolic functions

Etymology: Ergosterol takes its first half from "ergot", the name of a fungus that grows on rye and other cereal grasses. The French word "ergot" referred to the spur-like black bodies the fungus produces on grain, a shape that resembles a rooster's spur, and it is the source of the chemical's name. The second half, "sterol", is the standard chemical suffix for the steroid alcohols found in animal and plant cells, so the whole word simply means a sterol associated with ergot. The surprise lies in what the ergot fungus does. Its toxic alkaloids caused ergotism, a disease that swept medieval Europe after people ate contaminated bread, and modern chemists later used the same fungal family as a source of drugs. Ergosterol itself is a fungal membrane component rather than a toxin, and it matters because humans lack it: when ultraviolet light strikes it, it converts into vitamin D2, which is why mushrooms exposed to sunlight can supply that vitamin.