stearic acid
Học thuậtThân thiện
Definition
- Noun:
- A waxy saturated fatty acid: Stearic acid is a type of fatty acid that is solid and waxy at room temperature and is classified as saturated because its carbon chain contains no double bonds.
- A compound occurring widely as a glyceride: It is commonly found in nature not as a free acid, but chemically bonded to glycerol, forming part of fats and oils in both animals and plants.
Usage Examples
- Noun:
- Stearic acid is a common ingredient in candle making and soap production due to its hardness.
- The soap recipe calls for stearic acid to increase its firmness and lather stability.
- Many animal fats, like beef tallow, are rich in triglycerides containing stearic acid.
Advanced Usage
- In Biochemistry: In metabolic contexts, "stearic acid" refers specifically to the C18:0 fatty acid (18 carbon atoms, 0 double bonds), which is a fundamental molecule in lipid biosynthesis and energy storage.
- The enzyme stearoyl-CoA desaturase converts stearic acid into oleic acid.
Variants and Related Words
- Stearate (n): A salt or ester of stearic acid.
- Magnesium stearate is used as a flow agent in pharmaceutical tablets.
- Stearin (n): A triglyceride derived from stearic acid; or a mixture of such triglycerides.
- The stearin fraction of palm oil is high in stearic acid.
Synonyms
- Octadecanoic acid: The systematic IUPAC chemical name for stearic acid.
- C18:0: A common shorthand notation in nutrition and lipidology denoting a saturated fatty acid with 18 carbon atoms.
Related Phrases and Terms
- Saturated fatty acid: The broader class of compounds to which stearic acid belongs, characterized by no double bonds between carbon atoms.
- Animal and vegetable fats: The primary natural sources where stearic acid is found as a glyceride component.
Noun
- a waxy saturated fatty acid; occurs widely as a glyceride in animal and vegetable fats