What does sterol mean?
A sterol is a type of organic, steroid-derived alcohol found in the membranes of animal and plant cells, as well as in fungi and some microorganisms. Sterols contribute to membrane structure and the regulation of membrane fluidity, making them important to the functioning and survival of living organisms. Cholesterol is the best-known example in animal cells, while plants contain compounds such as sitosterol and stigmasterol; fungi commonly contain ergosterol. The term also has importance in nutrition because some dietary sterols can interfere with the absorption of cholesterol in the digestive tract. More broadly, sterols are studied in biochemistry, pharmacology, food science, and medicine, particularly in connection with membranes, metabolism, and cardiovascular health. Although closely related to steroids in chemical structure, the word “sterol” has a more specific meaning: it identifies steroid compounds with an alcohol functional group.
nounA naturally occurring organic compound belonging to the class of steroid alcohols. Sterols are components of cell membranes in animals, plants, fungi, and some microorganisms; cholesterol is a prominent example.
- Any member of a class of steroid alcohols occurring naturally in animals, plants, fungi, and some microorganisms, especially as a component of cell membranes.
"Cholesterol is a sterol that helps regulate the fluidity of animal cell membranes."
"The researchers identified several plant sterols in the seed oil."
"Ergosterol is a sterol found in fungal cell membranes and is the precursor of vitamin D₂."
Used when referring to multiple individual compounds or when discussing the class collectively, especially in biological and nutritional contexts.
"Plant sterols are present in nuts, seeds, and vegetable oils."
Cholesterol is a sterol, but this wider family of membrane-building compounds also helps plants, fungi, and microorganisms maintain the structure and fluidity of their cells.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sterol come from?
The word was formed in the early 20th century from Greek stereos, meaning “solid,” together with the chemical suffix -ol used in names of alcohols. Its underlying sense refers to the solid character of this class of chemical compounds. The Greek element also underlies related English words such as steric, stereochemistry, stereoscopic, and stereotype.
Related word forms
How sterol is actually used
This is primarily a technical term in biochemistry, nutrition, pharmacology, and related sciences. In general prose, cholesterol is much more widely understood than other individual sterols.
Easily confused with sterol
A steroid is a broader class of organic compounds with a characteristic four-ring structure, whereas a sterol specifically denotes a steroid alcohol such as cholesterol.