Lipids - Structure Flashcards
What are the main FOUR classes of lipids?
- Fatty acids
- Triacylglycerols
- Phospholipids
- Steroids
What are the features of Fatty Acids?
- Hydrocarbon chain
- Insoluble in water
- Highly soluble in organic solvents
- Known as mono carboxylic acids
What is the difference between saturated and unsaturated fatty acids?
Saturated fatty acids have the maximum number of hydrogen atoms possible and no double bonds.
Unsaturated fatty acids have one or more double bonds and don’t have maximum number of hydrogens
What does 18:1∆9 mean in regards to an unsaturated fatty acid?
18 carbons
1 double bond
Double bond position - between C9 and C10
TRUE OR FALSE: Saturated and unsaturated have the same melting points
FALSE.
Unsaturated fatty acids have a lower melting point
Does the chain length of a fatty acid have an impact on the melting point?
YES. The longer the chain, the higher the melting point
What are the two types of Triacylglycerols?
SIMPLE - have the same fatty acid in all three chains
MIXED - 2 or more different fatty acids in each chain
What is the structure of a Phospholipid?
2 Fatty Acids + Phosphate group + an Alcohol, attached to Glycerol
Describe an Amphipathic molecule
Contains both polar and non-polar groups (hydrophilic and hydrophobic)
Where are the fatty acid chains attached to on the glycerol in a Phospholipid?
Carbons 1 and 2
Where is the alcohol attached to on the glycerol in a Phospholipid?
Carbon 3
How are steroids characterised?
A carbon skeleton consisting of FOUR fused rings (3 with 6C and 1 with 5C)
Name a common Steroid
Cholesterol
What type of Lipid is most abundant in plasma membranes?
Phospholipids
