3.5 - Lipids Flashcards
What are lipids?
Molecules containing carbon, hydrogen and oxygen.
What are fats?
Lipids that are solid at room temperature.
What are oils?
Lipids that are liquid at room temperature.
Are lipids polar or non-polar?
Non-polar
Why are lipids non-polar?
The electrons in the outer orbitals that form bonds are more evenly distributed than in polar bonds, which means there are no positive or negative areas in the molecule.
How is a triglyceride made?
1 glycerol molecule is combined with 3 fatty acids.
Are lipids macromolecules?
Yes
What are macromolecules?
Large complex molecules that are not built from repeating units like monomers.
What are phospholipids?
They are modified triglycerides which contain phosphorus as well as carbon, hydrogen and oxygen.
How are phospholipids made?
One of the fatty acid chains n a triglyceride molecule is replaced with a phosphate group.
Are phospholipids polar or non-polar?
The tail is non-polar
What are the biological roles of lipids?
- Membrane formation and the creation of hydrophobic barriers
- Hormone production
- Electrical insulation necessary for impulse transmission
- Waterproofing e.g. on birds’ feathers + on plant leaves
Other roles of lipids:
- Provides long-term energy storage
- Thermal insulation to reduce heat loss e.g. in penguins
- Cushioning to protect vital organs such as the heart and kidneys
- Buoyancy for aquatic animals such as whales.
