Fats and oils have the same basic structure. They are made up of three acids which have formed ester bonds with . They are often called tri-glycerides.

Fatty acids are large . They have a [?] backbone consisting of twenty or thirty carbon atoms. If all the carbon atoms are separated by single bonds, the chain is called . If there is one or more double bond, the chain is .

Animal fats consist of mostly saturated fat. They tend to be at room temperature.

Plant tri-glycerides are unsaturated, and are at room temperature. Therefore, they are called .

[?] was made as a cheap form of butter. Plant oils are treated to fet rid of some of the double bonds in a process called [?].

The result of this is that a lot of fatty acids are made. These are not healthy to eat and can raise cholesterol and lead to a [?] attack.