Learning Maths and Science Textbook | Page 14

Lard is an animal fat (from pig) Butter is made from milk, which is an animal fat Animal fats are fatty acids with some sort of animal source. This can be the fat from the animal's body or some sort of dairy product. Animal fats are solid at room temperature; their liquid counterparts are called animal oils. 3. Cis- and trans-fats Because of their chemical structure, unsaturated fatty acids can have cis-trans-isometry. This means that the double bond between two carbon atoms can make the carbon chain to be on the same side or the opposite sides of the double bond. If the parts of the chain are on the same side of the double bond, they are called cis-fatty acids and they make a bend in the molecule structure. Most of the naturally occurring fatty acids are cis-fatty acids and they are liquid at room temperature. Cis-2-butene Trans-2-butene 13