#4: Lipids Flashcards
Function
Long term energy, insulation, protection of internal organs, chemical signals, cellular membrane
Structure
Primary structure - hydrocarbon chain
Some may contain functional groups
Fats (Triglycerides)
General structure- glycerol backbone and 3 fatty acid chains
These components will undergo condensation reaction to form “triglyceride”
Bond between glycerol and fatty acid chain called ESTER LINKAGE
Glycerol
3 carbon chain with 3 hydroxyl groups
Can form bond with 3 fatty acid chains
One fatty chain will bind with hydroxyl group
Fatty Acid Chains
Hydrocarbon chains that are long/short, saturated/unsaturated
Each fatty chain has carboxyl group
Saturated fats
No double bonds
Straight
Lie flat- strong intermolecular forces, some ah-bonds, so hard to break down
Solid at room temp
Ex: animal fat - lard/butter
Unsaturated fats
One or more double bonds
Crooked shape- weaker forces, less H-bonds
Liquid at room temp
Ex: plant fats- olive oil
Phospholipids
Structure: glycerol backbone, phosphate group, nitrogen group, 2 fatty acid chains
Two sections:
- Head (hydrophilic)- consists of glycerol backbone, phosphate group, nitrogen group
- Tail (hydrophobic)- consists of 2 fatty acid chains
Cell membrane composed of phospholipid bilayer
Phospholipid bilayer
Water, polar/ionic cannot pass through non-polar tails
Has transport proteins and hydrophilic channels to move materials through
Steroids
Non polar
Hydrophobic
Contains four hydrocarbon rings and various functional groups
Steroids uses
Cholesterol - keep the cell membrane fluid-like
Sex hormones -testosterone, estrogen
Waxes
Formed via condensation reaction between long-chain fatty acid (carboxyl) and long-chain alcohol (hydroxyl)
Hydrophobic
Wax uses
Plant:
Cutin- shiny layer on leaves to make a waterproof barrier
Animal:
Bird wax- to keep feathers dry
