AP Biology Lipids
Transcript AP Biology Lipids
Lipids: Fats & Oils
Lipids are composed of C, H, O
Do not form polymers
big molecules made of smaller subunits
not a continuing chain
Six functions of lipids:
1. Long term energy storage
2. Protection against heat loss
3. Protection against physical shock
4. Protection against water loss
5. Chemical messengers (hormones)
6. Major component of membranes
Fats store energy
2x energy of
think whale blubber!
Why do humans
like fatty foods?
glycerol (3C alcohol) + fatty acid
fatty acid =
long “tail” with COOH group at “head”
Fatty Acid Structure
•Carboxyl group (COOH) forms the acid.
•“R” group is a hydrocarbon chain (chain of hydrogens and carbons).
A Representative Fatty Acid
All C bonded to H
No C=C double bonds
long, straight chain
most animal fats
solid at room temp.
= plaque deposits
C=C double bonds in
the fatty acids
plant & fish fats
liquid at room temperature
the kinks made by double
bonded C prevent the
molecules from packing
Saturated vs. unsaturated
• Ear wax – protection from foreign materials/ invaders
(such as insects)
• Wax coating on leaves – forms a barrier to keep water
Found in cell membranes – keeps them
Hormones (chemical messengers)
What are the four types of lipids ?
Name as many functions of lipids as possible (6).
What is the difference in saturated & unsaturated ?
How could you tell the difference in saturated &
unsaturated by looking at an item ?
What is healthier, saturated or unsaturated fats ?
Lipids contain more energy than carbs, so why are
carbs are primary energy source ?
What is the monomer & polymer of lipids ?
Structurally, how do you tell the difference in carbs
& lipids ?
1. Fats, oils, waxes, & steroids
2. Energy storage, insulation, protection from water loss,
protection against physical shocks, chemical
messengers, component of cell membranes
C=C double bonds are in unsaturated
Saturated are solid at room temp., unsaturated are liquid
at room temp.
Lipids are harder to break down, because they are
insoluble in water
Technically, there are not monomers & polymers
Both contain C,H, & O, but in carbs they are in a 1:2:1