Ch 5 - Lipid Structure And Function Flashcards
Lipid
Characterized by insolubility in water and solubility in nonpolar organic solvents
Amphipathic
Molecules with this characteristic have a hydrophilic and a hydrophobic region. Polar head is hydrophilic. The fatty acid tail is hydrophobic
Phospholipids
Contain a phosphate and an alcohol that comprise the polar head group joined to a hydrophobic fatty acid tail by phosphodiester linkages
Glycerol
3 carbon alcohol
Forms phosphoglycerides or glycerophospholipids
Saturated fatty acid
The tails have only single bonds
Carbon bond is considered saturated when it is bound to 4 other atoms with no pi bonds
Greater van der Waals forces and more stable structure
Unsaturated fatty acid
Includes one or more double bond which introduce kinks into the fatty acid chain which makes it difficult for them to stack and solidify
Glycerophospholipids
Also called phosphoglycerides
Phospholipids that contain a glycerol backbone bonded by ester linkages to two fatty acids and by a phosphodiester linkage to a highly polar head group
Sphingolipids
Sphingosine or sphingoid backbone
Not all are phospholipids
Glycolipid
Any lipid containing glycosidic bonds to sugar
Four major subclasses of sphingolipids
Ceramides
Sphingomyelins
Glycosphingolipids
Gangliolipids
Ceramide
Major class of Sphingolipid with single hydrogen atom as its head group
Sphingomyelins
Major class of sphingolipids that are also phospholipids
Have either phosphatidylcholine or phosphatidylethanolamine as a head group and thus contain a phosphodiester bond
Major component in plasma membranes of cells producing myelin, the insulating sheath for axons
No net charge
Glycosphingolipids
Major class of sphingolipids that are also glycolipids Not phospholipids, ie no phosphodiester linkages mainly found on outer surface of plasma membrane Further classified as either cerebrosides or globosides
Cerebrosides
Glycosphingolipids with a single sugar
No net charge at physiological pH
Globosides
Glycosphingolipids with two or more sugars
No net charge at physiological pH