1. Activity #8: Lipids

2. Vocabulary Lipids Fats Oils Phospholipids Triglycerides Steriods
Unsaturated fatty acids
Saturated fatty acids

3. Lipids Important for energy, cell structure, and waterproof coatings
Generally not soluble in water
Contain C, H, O (NOT in a 1:2:1 ratio)
Ex: Oleic Acid is C18H34O2
Do not have a repeating structural monomer unit
Do not technically form polymers
Different lipids have different structures

4. Types of Lipids
Fats- triglycerides: solid at room temperature; usually from animal sources
Examples: butter, shortening, lard
Oils- triglycerides: liquid at room temperature; usually from plant sources
Examples: sunflower oil, olive oil, corn oil
Waxes: ear wax, beeswax, and the waxy layer on the surface of plant leaves.
Steroids: cholesterol; hormones such as testosterone; pigments used in animal vision and in photosynthesis.
Phospholipids: important structural component of cell membranes

5. Triglycerides
Lipids that form when a glycerol molecule combines with 3 molecules called fatty acids
Structure of the fatty acid determines the function of the triglyceride
Glycerol
3 fatty acids

6. Saturated Fatty acids
A fatty acid is SATURATED if each carbon in a lipid’s fatty acid chain is bonded to another carbon atom by a single bond (no C=C double or triple bonds)
tend to form molecules called Saturated fats which are solid at room temperature
contain the maximum amount of hydrogens possible
not very 'heart-healthy'!

7. Unsaturated Fatty acids
A fatty acid is UNSATURATED if there is at least one carbon-carbon double bond
monounsaturated will have 1 double bond
A fatty acid is said to be POLYUNSATURATED if there are more than one carbon-carbon double bond
tend to form molecules called oils which are liquid at room temperature
contain fewer hydrogens
more "heart-healthy"!

8. Formation of Triglycerides
Fatty acids are attached to the glycerol molecules by dehydration synthesis
Occurs at the carboxyl end of each fatty acid
Carboxyl group can be written as COOH or -COOH
Carboxyl group contains a carbonyl (C=O) group and a hydroxyl (–OH) group.
Carbonyl
Carboxyl group
Hydroxyl
How many water molecules are removed in the formation of 1 triglyceride? 3

9. Triglycerides
Why do you think saturated fats are solid and unsaturated fats are liquids? Think about the structure/layout of each.
Saturated
Unsaturated

10. Fatty Acids
Melting point is the temperature at which a substance melts.
Which one of the fatty acids in the table is saturated?
Which is monounsaturated?
Which are polyunsaturated?
How does the number of double bonds affect the melting point?
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