mod8 waxes, phospholipids

what are waxes:

a fatty acid reacted with a long chain alcohol

are waxes saponifiable:

yes because they have an ester

explain waxes solubility:

insoluble in water due to large non-polar portion

explain general structure of phospholipids:

glycerol backbone

2 fatty acid chains

1 phosphate group

explain a phosphate ester:

bond between OH group and phosphoric acid group

explain arrangement of phospholipids in aqueous solutions:

polar heads in contact with aqueous environment

non-polar tails buried in bilayer

what determines strength of bilayer:

many saturated fatty acid chains = rigid

many unsaturated fatty acid chains = floppy

how is the strength of the lipid bilayer strengthened:

cholesterol is used to increase rigidity

describe sphingolipids:

doesn’t have glycerol backbone

has sphingosine

fatty acid and a phosphate group

where are sphingolipids found:

found in brain and nervous tissue

describe structure of steroids:

basic 4 ring structure

are steroids saponifiable?

no because they do not contain esters

what are the functions of steroids:

chemical messengers

control lipid membrane fluidity

what is cholesterol:

apart of all cell membranes, female and male sex hormones

what is a lipoproteins:

lipids form complexes with proteins

what do different lipoproteins do?

carry different types of fats

function of low density lipoproteins:

carry fat around the entire body within the bloodstream

function of high density lipoproteins:

collect fat from cells and tissues and return it to the liver

explain androgens:

male sex hormones

synthesised in the testes

responsible for male secondary sex characteristics

explain estrogens:

female sex hormones

synthesised in the ovaries

responsible for female secondary sex characteristics

function of prostaglandins:

hormone like effects, produced on site of damage/infection