1. Malcolm Stephens

2. Naturally occuring
Animal fat
Vegetable oil
Marine oil
lard
suet
sunflower oil
coconut oil
cod liver oil
whale oil

3. Fats and oils are built from an alcohol with three -O-H groups.
glycerol
Systematic name is propane-1,2,3-triol

4. The other components of fat molecules are carboxylic acids
such as
Stearic acid
Systematic name is octadecanoic acid

5. Fats are mainly built from carboxylic acids with C-C single bonds.
Stearic acid in beef fat
notice that with only C-C bonds the molecule is “straight”

6. Oils have some C=C bonds in the carboxylic acids from which they are made.
Oleic acid in olive oil
notice that the shape of the molecule is distorted by the C=C bond

7. Fat
Fat molecules pack together tightly, making fats solid at room temperature.
Double bonds in oil make the molecule less compact.
Oil
Less tightly packed molecules make oils liquid because the bonds between molecules are weaker.

8. In practice both fats and oils are mixtures of esters containing both saturated and unsaturated compounds.
Beef Fat
Olive oil
In general oils have a higher proportion of unsaturated molecules.