complex lipids - "other" lipids

what are the 2 main backbones of lipids ?

glycerol and sphingosine

unsaturated fatty acids

have 1+ double C bond

lysophospholipids are missing a fatty acid at what carbon ?

2nd

role of LPLs

act as ligands - bind to 7 trans mem G protein coupled receptors

where are sphingolipids found ?

mammalian mems esp. nerve tissue

role of sphingolipids

add rigidity to area of mem helping to induce permeabilisation

ceramides usually contain fatty acids of what length ?

>16 C

where are ceramides found in large quantities ?

stratum corneum of skin (epidermis)

role of ceramides

act as barrier to prevent evaporation

ceramides can be esterified to form

sphingomyelins

sphingosine

ceramide

sphingomyelin

role of sphingomyelins

insulation and protection of nerve axons

what is a lipid raft ?

areas of plasma membrane enriched in sphingolipids

diameter of lipid raft

70nm

role of lipid rafts

organisation of proteins, conversion of exracellular signals

lipid rafts are transient meaning they temporarily form for how long ?

seconds to 4 mins

in animal cells glycolipids are derived from

sphingosine

glycolipid

a glycolipid with a single sugar residue linked to the primary hydroxyl group is called ?

a cerebroside

what does the mis-regulation of glycolipid metabolism lead to ?

neurodegenerative disorders

glycolipids with chains of 7+ sugar residues are called ?

gangliosides

cholesterol is a derivative of…

tetracyclic hydrocarbon

role of cholesterol

constituent of cell mem, precursor for steroid hormones, D-vitamins and bile salts

oxysterol

oxidised form of cholesterol - its precursor

where do the sugar residues of gangliosides sit ?

extracellular environment

the addition of what sugar residue results in A antigen ?

acetylgalactosamine

the addition of what sugar residue results in B antigen ?

galactose

what are the primary steroid hormones derived from cholesterol ?

progesterone estrogen androgens glucocorticoids mineralcorticoids

vitamin D and its metabolites are important for…

absorption of calcium and phosphate from diet

D vitamin

oxysterols are formed by what ?

CYP450 enzymes or 25-hydroxylase

in animals glycosyl glycerides are limited to what tissue ?

nervous

the main structural lipids in plants are

glycosyl glycerides and sulphoquinovosyl