Glycerides, more correctly known as acylglycerols, are
esters formed from
glycerol and
fatty acids, and are generally very hydrophobic.
Glycerol has three
hydroxyl functional groups, which can be esterified with one, two, or three fatty acids to form
mono-
Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example:
* unicycle, bicycle, tricycle (1-cycle, 2-cycle, 3-cyc ...
,
di-
Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example:
* unicycle, bicycle, tricycle (1-cycle, 2-cycle, 3-cyc ...
, and
triglycerides.
These structures vary in their fatty acid alkyl groups as they can contain different carbon numbers, different degrees of unsaturation, and different configurations and positions of olefins.
Vegetable oils and
animal fat
Animal fats and oils are lipids derived from animals: oils are liquid at room temperature, and fats are solid. Chemically, both fats and oils are composed of triglycerides. Although many animal parts and secretions may yield oil, in commercial p ...
s contain mostly triglycerides, but are broken down by natural
enzymes (
lipase
Lipase ( ) is a family of enzymes that catalyzes the hydrolysis of fats. Some lipases display broad substrate scope including esters of cholesterol, phospholipids, and of lipid-soluble vitamins and sphingomyelinases; however, these are usually tr ...
s) into
mono
Mono may refer to:
Common meanings
* Infectious mononucleosis, "the kissing disease"
* Monaural, monophonic sound reproduction, often shortened to mono
* Mono-, a numerical prefix representing anything single
Music Performers
* Mono (Japanese b ...
and
diglycerides and free fatty acids and glycerol.
Soaps are formed from the reaction of glycerides with
sodium hydroxide
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions .
Sodium hydroxide is a highly caustic base and alkali ...
. The product of the reaction is glycerol and salts of fatty acids. Fatty acids in the soap
emulsify
An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Altho ...
the oils in dirt, enabling the removal of oily dirt with water.
Partial glycerides are esters of glycerol with fatty acids, where not all the
hydroxyl groups are esterified. Since some of their hydroxyl groups are free their molecules are
polar
Polar may refer to:
Geography
Polar may refer to:
* Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates
* Polar climate, the c ...
. Partial glycerides may be
monoglycerides (two hydroxyl groups free) or
diglycerides (one hydroxyl group free).
Short chain partial glycerides are more strongly polar than long chain partial glycerides, and have excellent solvent properties for many hard-to-solubilize drugs, making them valuable as
excipients in improving the formulation of certain pharmaceuticals.
The most common forms of acylglycerol are
triglycerides, having high
caloric value
Caloric is a brand of kitchen appliances, which dates back to 1903.
History
Caloric Corporation began as the Klein Stove Company in Philadelphia in 1890. The Caloric brand was introduced in 1903. It was reorganized in 1946 as the Caloric Stove C ...
and usually yielding twice as much energy per gram as carbohydrate.
Acylglyceride linkage
An acylglyceride linkage is the
covalent bond
A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. The stable balance of attractive and repulsive forces between atoms ...
between the
organic acid
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are rel ...
groups (such as
fatty acid) and one of the three
hydroxyl groups of
glycerol.
[Moore, Randy, et al. (1998) ''Botany.'' 2nd Ed. New York: WCB/McGraw Hill. .]
References
{{Authority control
Lipids
Glycerol esters