Lipids

2 lipid groups

Triglycerides and phospholipids

Triglyceride formation

one molecule of glycerol and three molecules of fatty acid

condensation reaction

ester bond

How is an ester bond formed

A condensation reaction between glycerol and a fatty acid

What do all lipids contain

Hydrocarbons

structure of fatty acids

long tails made of hydrocarbons

tails are hydrophobic

lipids are _______ in water

Insoluble

two types of fatty acids

saturated and unsaturated

saturated fatty acid structure

single bonds between carbon atoms

unsaturated fatty acids structure

double bonds between carbon atoms

causes the chain to kink

where are phospholipids found

cell membranes

formation of phospholipids

two fatty acids

one glycerol molecule

a phosphate group

phosphate group is _________

hydrophilic (attracts water)

What are triglycerides used as

energy storage molecules

good: long hydrocarbon tails from fatty acids contain lots of chemical energy, released when broken down.

R group definition

Variable group

Function of phospholipids

hydrophilic head interacts with water

hydrophobic tail repels water

creates double layer, phospholipid bilayer (cell membrane)

Test for lipids

add ethanol to sample and mix

then add distilled water

positive test clear to white emulsion