Structures, Occurrence, Biochemistry, and Functions
Lipids are a diverse range of compounds for which no internationally agreed definition exists. In the first section in our article on nomenclature, we discuss the merits of several possible definitions, i.e., based on solubility in organic solvents, their structure/functions, biosynthetic mechanisms or chemical structures alone. Personally, I prefer the last of these, but readers can decide for themselves. A general summary of the structures, occurrence, composition, chemical and physical properties, basic biochemistry and functions of these vital and fascinating natural compounds is presented in this section of the website. In particular, the first articles listed below describe in general terms what lipids are and why they are so important in nature.
|Lipids: definitions, classification and nomenclature
|A lipid primer - the diversity of natural lipids
|Lipids in action - their biological functions
|Lipid compositions of animal tissues
|Lipid compositions of plants and microorganisms
Further documents in the 'Lipid Essentials' topic of this website are grouped into four main sections according to chemical structures, and they can be addressed from the following links -
| Fatty acids and oxylipins
e.g., saturated to polyunsaturated fatty acids, prostanoids, eicosanoids, etc.
| Simple lipids - glycerolipids, sterols, lipoproteins, etc.
e.g., triacylglycerols, cholesterol, proteolipids, waxes and various miscellaneous
| Complex glycerophospho- and glyceroglyco-lipids
e.g., phosphatidic acid, phosphatidylcholine, glycosyldiacylglycerols, etc.
e.g., sphingoid bases, ceramides, sphingomyelin, gangliosides, etc.
Related lipids are grouped together as far as possible in these web pages, but there are some that do not fit easily into any group and most of these are listed with the simple lipids for reasons of practical convenience.
These essays are aimed at generalists or those who are new to lipid science, especially young scientists - not experts in particular disciplines. My approach based on individual lipid classes has limitations, not least in that the metabolism of different lipids is highly integrated, but the reading lists at the end of each web page may compensate for this by facilitating access to the primary literature and providing for those who require a more specialized knowledge. Our Literature Survey pages contain comprehensive lists of those publications consulted during the writing of this section of the site in addition to references on analytical methodology. You will not find much on nutritional aspects of lipids here.
These web pages are updated regularly as new information becomes available, so the author considers them to be a work in progress that will never be completed.
I can recommend the following websites that provide complementary information to this - our host site Lipid Maps - lipid systematics, structures, lipidomics; www.cyberlipid.org - lipid structures, composition; the AOCS Lipid Library - analysis, chemistry, nutrition.
|© Author: William W. Christie
|Updated: February 1st, 2023