Ch. 8 Lipids

all biological lipids are ….

amphipathic (have polar and nonpolar groups)

6 classes of lipids

1. fatty acids

2. triacylglycerols

3. glycerophopholipids

4. sphingolipids

5. waxes

6. isoprene-based lipids

saturated vs unsaturated fatty acids

saturated- carbons with no double bonds and saturated with Hydrogen

unsaturated- carbons with double bonds

name the 5 saturated fatty acids and their amount of carbons

1. lauric acid- 12C

2. myristic acid- 14C

3. palmitic acid- 16C

4. stearic acid- 18C

5. arachidic acid- 20C

name the 6 unsaturated fatty acids and their carbon to double bond ratio

1. palmitoleic acid(16:1)

2. oleic acid (18:1)

3. linoleic acid (18:2)

4. a-linolenic acid (18:3)

5. y-linolenic acid (18:3)

6. Arachidonic acid (20:4)

what are fatty acids comprised of?

alkyl chains terminated by carboxylic acid groups

what does the term saturated indicate ?

the acyl chain is fully reduced or saturated with hydrogens

formation of saturated vs unsaturated chains

saturated chains- packed tightly and form more rigid, organized aggregates

unsaturated chains- bend and pack in a less ordered way, with greater potential for motion

Glycerophospholipids

1,2-diacylglycerol that has a phosphate group esterified at carbon 3 of the glycerol backbone

Apart of the cell membrane

Sphingosine

18 carbon alcohol that forms the backbone of the sphingolipids

Glycospingolipids

Ceramide (fatty acid and sphingosine) with one or more sugars in beta-glycosidic linkage at the 1-hydroxyl group

Cerebrosides vs gangliosides

Cerebrosides- glycoshingolipids with one sugar

Gangliosides- ceramides with 3 or more sugars, one of them being Salic acid (important component of muscle and nerve membranes)

Waxes

Esters of long chain alcohols with long chain fatty acids

Insoluble in water due to hydrocarbon composition (water repellent)

terpenes

Terpenes- class of lipids formed from combination of isoprene units

Isoprene vs monoterpene vs sesquiterpene vs diterpene

Isoprene- 2-metal-1,3-butadiene

Monoterpene- two isoprene units

Sesquiterpene- three isoprene units

Diterpene- four isoprene units

Steroids

Polyprenyl(isoprene-based) molecules built on a core structure of three 6 membered rings and one 5 membered ring all fused together