1.3 Lipids Flashcards
Describe the formation of a triglyceride
- 3 condensation reactions
- Between 3 fatty acids and 1 glycerol
- Loss of 3 water molecules
- Formation of 3 ester bonds
Why are triglycerides good respiratory substrates
- Low oxygen contnet
- High energy conent
Why are triglycerides good for waterproofing
They have hydrophobic fatty acids
Why are triglycerides good thermal and electrical insulators
They are non-polar molecules
Draw a triglyceride (and the products from making it) , and label the ester bond
Describe a saturated fatty acid
- No double bond between carbon atoms
- In the hydrocarbon chain
- Unable to accept more hydrogen
Describe an unsaturated fatty acid
- At least one double bond between adjacent carbon atoms
- In the hydrocarbon chain
- Therefore able to accept more hydrogen
Describe the formation of a phospholipid
- 3 condensation reactions
- Between 2 fatty acids, 2 glycerol and 1 phosphate group
- Loss of 3 water molecules
- Formation of 3 ester bonds
What is the property of a phospholipid that allows it to form bilayers
Amphipathic
What part of the phospholipid is hydrophobic
The fatty acid ‘tail’
What part of the phospholipid is hydrophillic
The phosphate and glycerol ‘head’
Similarities between phospholipids and triglycerides
- Contain ester bonds between glycerol and fatty acids
- Contain glycerol
- Fatty acids can be saturated or unsaturated
- Insoluble in water
Points of comparison, comparing triglycerides and phospholipids
- Elements they contain
- Components (not glycerol)
- Polar/non-polar reigons
- Form a bilayer in water?
Describe how to test for the presence of lipids
- Crush/grind the sample
- Add ethanol to sample and shake
- Add water to sample and shake
- A milky white emulsion will form if positive
