Lipids Flashcards
What are triglycerides made up of?
One glycerol molecule and three fatty acids.
What is an unsaturated fatty acid?
A fatty acid that has a double bond.
What is a saturated fatty acid?
A fatty acid that does not have a double bond.
How is a triglyceride made?
Condensation reactions between the glycerol molecule and the three fatty acids lead to the formation of three ester bonds and the removal of water.
What is the function of a triglyceride?
They can be a source of energy and water.
How is the structure of a triglyceride linked to its function?
They contain many C-H bonds that store a lot of energy; when they are broken they release a lot of energy. They contain many OH bonds that when hydrolysed release water. They are insoluble; so they don’t affect the water potential of cells and draw water into them via osmosis.
What is a phospholipid made up of?
A glycerol molecules, 2 fatty acids and one phosphate molecule.
What is the function of phospholipids?
They make up the bilayer of cell membranes and help the cell membranes control what leaves and enters the cell.
How is the structure of phospholipids linked to its function?
The fatty acids are hydrophobic and the phosphate is hydrophilic so in water the phosphates turn towards the water and the fatty acids point away from the water and towards each other. This creates a hydrophobic bilayer that only allows lipid-soluble substances through.
What is the test for a lipid?
- Add ethanol.
- Add water and shake thoroughly.
- If a white emulsion forms then a lipid is present.
