What are lipids?
Molecules containing the element, carbon hydrogen and oxygen.
Biological molecules that can be dissolved in organic solvents such as alcohol, but not water
What do lipids include?
Fatty acids, triglycerides, phospholipids and cholesterol.
They are fats is solid at room temp and oil if liquid at room temp.
What are the uses of lipids?
Energy storage
Cell membranes
Insulation
Waterproofing.
Protection/padding
Hormones
What are triglycerides made up of?
One glycerol and three fatty acids.
Formula is CH3 (CH2), nCOOH
How are triglycerides formed?
The hydroxyl groups interacts leading to the formation of three water, molecules and Esther bonds between the glycerol and fatty acid.
What are saturated fatty acid?
Fatty acids that have no double bonds between the carbons.
What are unsaturated fatty acids?
Fatty acids that have double bonds between the carbon atoms
What does double bond do to unsaturated fatty acid?
Makes them kink or bend. This causes them to be unable to park as closely together as saturated fatty acids.
What are phospholipids?
Contains five triglycerides that contain a phosphate ion in place of one fatty acid chain
(Phosphate iron is negatively charged – makes it soluble in water).
What is the structure of phospholipids?
Non-polar tail which is hydrophobic.
Polar head which is hydrophilic.
Where is cholesterol mainly manufactured in the body
The liver and intestine
It plays a key role in the formation of cell membranes.
What is the function of cholesterol?
To add stability and help regulate the fluidity by keeping the fluid out low temperatures.
What is the test for lipids?
Emulsion test
1. Sample is mixed with ethanol
2. Solution is mixed with water and shaken
3. If white emotion forms – indicates presence of lipid
4. If solution remains clear, no lipid is present.
