Lipid | Definition, Structure, Examples, Functions, Types, & Facts ...
Although biological lipids are not large macromolecular polymers (e.g., proteins, nucleic acids, and polysaccharides), many are formed by the chemical linking of several small constituent molecules. Many of these molecular building blocks are similar, or homologous, in structure.
Fatty acid | Definition, Structure, Functions, Properties, & Examples ...
2024年11月7日 · Fatty acid, important component of lipids in plants, animals, and microorganisms. Generally, a fatty acid consists of a straight chain of an even number of carbon atoms, with hydrogen atoms along the length of the chain and at one end of the chain and a carboxyl group (—COOH) at the other end.
Understanding lipids and their characteristics | Britannica
One of the three large classes of substances in foods and living cells, lipids contain more than twice as much energy (calories) per unit of weight as the other two (proteins and carbohydrates).
Cell - Lipids, Phospholipids, Membranes | Britannica
2024年10月31日 · Membrane lipids are principally of two types, phospholipids and sterols (generally cholesterol). Both types share the defining characteristic of lipids—they dissolve readily in organic solvents—but in addition they both have a region that is attracted to and soluble in water. This “amphiphilic” property (having a dual attraction; i.e ...
Lipid - Structure, Function, Types | Britannica
All the lipids are amphipathic, with their hydrophilic (polar) and hydrophobic (nonpolar) portions located at separate parts of each molecule. As a result, the lipid components of membranes are arranged in what may be called a continuous bimolecular leaflet, or bilayer.
Lipid - Saturated Fatty Acids | Britannica
Lipid - Saturated Fatty Acids: The simplest fatty acids are unbranched, linear chains of CH2 groups linked by carbon-carbon single bonds with one terminal carboxylic acid group. The term saturated indicates that the maximum possible number of hydrogen atoms are bonded to each carbon in the molecule.
Biomolecule | Definition, Structure, Functions, Examples, & Facts ...
2024年10月21日 · Lipids, another key biomolecule of living organisms, fulfill a variety of roles, including serving as a source of stored energy and acting as chemical messengers. They also form membranes , which separate cells from their environments and compartmentalize the cell interior, giving rise to organelles , such as the nucleus and the mitochondrion ...
Lipid - Cholesterol, Sterols, Lipoproteins | Britannica
Isoprenoids encompass diverse biological molecules such as steroid hormones, sterols (cholesterol, ergosterol, and sitosterol), bile acids, the lipid-soluble vitamins (A, D, E, and K), phytol (a lipid component of the photosynthetic pigment chlorophyll), the insect juvenile hormones, plant hormones (gibberellins), and polyisoprene (the major ...
Lipid - Fats, Oils, Phospholipids | Britannica
2024年9月20日 · Lipid - Fats, Oils, Phospholipids: There are four major classes of circulating lipoproteins, each with its own characteristic protein and lipid composition. They are chylomicrons, very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and …
Cell Membrane, Lipid Bilayer & Fatty Acids - Britannica
2024年10月11日 · Phospholipid, any member of a large class of fatlike, phosphorus-containing substances that play important structural and metabolic roles in living cells. The phospholipids, with the sphingolipids, the glycolipids, and the lipoproteins, are called complex lipids, as distinguished from the simple