Lipids
Lipids are composed of:
• Carbon
• Hydrogen
• Oxygen
“CHO”
BUT: Lipid molecules have a larger number
of Carbon and Hydrogen and a smaller
number of Oxygen than Carbohydrates
Lipid Functions
• Lipid molecules provide a barrier b/t a cell and
its watery environment
Lipid Functions
• Insulation of whales and walruses
Lipid Functions
• Skin oils help repel
water from feathers of
ducks
Lipid Functions
• Waxy layer of plants,
keeps water in
Fatty Acids
• Lipids are composed of building blocks or
MONOMERS called Fatty Acids.
Yellow
Pink/Red
Fatty Acids
• Carboxyl end (-COOH)
– polar
– Hydrophilic:
“water loving”
– Hydrocarbon end (CH3)
• Non-polar
• Hydrophobic: “Water fearing”
WATER
Arrangement of FA in Cell
Functions of Lipids
• Store Energy!!
• Fats have more H bonds than Carbs and
can store more energy.
Kinds of LIPIDS
1. Triglycerides
2. Waxes
3. Steroids
4. phospholipids
Triglycerides
Composed of:
1. 1 glycerol molecule
2. 3 molecules of fatty acids
TWO categories of triglycerides
1. Saturated
2. unsaturated
Waxes
• Plant waxes
– Forms protective
coating on outer
surface
• Earwax
– Prevents bacteria from
entering middle ear
Steroids
• Composed of 4
carbon rings
• Found :
–
–
–
–
–
Hormones
Toad venom
Plant poisons
Chlorophyll
Cholesterol
THE END