Sterols

• Sterols, also known as steroid alcohols, are a subgroup of the steroids and an important class of organic molecules. They occur naturally in plants, animals, and fungi, with the most familiar type of animal sterol being cholesterol. 
• Cholesterol is vital to cellular function, and a precursor to fat-soluble vitamins and steroid hormones.
• Sterols of plants are called phytosterols and sterols of animals are called zoosterols. Important zoosterols are cholesterol; notable phytosterols include campesterol, sitosterol, and stigmasterol. 
• Ergosterol is a sterol present in the cell membrane of fungi, where it serves a role similar to cholesterol in animal cells.