1. Lipids Structure Elements: Carbon (C), Hydrogen (H), Oxygen (O)
Fatty acids are long hydrocarbon chains
Nonpolar!
Classes of Lipids
Fats; Monomers – 3 fatty acids & glycerol molecule
Waxes; Monomers – fatty acid & alcohol molecule
Steroids (ex – cholesterol); made of 4 fused carbon rings

2. Lipids
Steroid
Fatty Acid
Wax
Cholesterol

3. Lipids
Phospholipid
Triglyceride
*Most common*

4. Lipids More about Fatty Acids
Fatty acids can be saturated or unsaturated
Saturated Fats: solid at room temperature
Unsaturated Fats: liquid at room temperature (usually)
You should eat
more unsaturated
fats

5. Lipids
Function
Fats – HUGE energy source but used as energy storage; insulation; cushion for organs (carbs are used 1st because they’re easier to break down)
Phospholipids – form cell membrane
Steroids – communication; controls many body processes (hormones)
Examples

6. Lipids
Carbs & Lipids both provide energy for your body Which biomolecule provides more energy? Why? *Hint: What do bonds represent?
Because lipids have more bonds than a carbohydrate, lipids can release more energy as they are broken down.
Why does your body use carbs for energy before lipids?
Because lipids have more bonds than a carbohydrate, lipids take more work to break down than a carb. Your body chooses the easiest option.

7. Lipids Many lipids are formed from glycerol & --- ?
A. Fatty Acids B. Phospholipids
C. Disaccharides D. Nucleic Acids
Which of the following is true about energy?
Carbs store energy
Lipids store energy
Carbs provide more energy per gram than lipids
Lipids provide more energy per gram than carbs

8. Show What You Know: Lipids
What elements make up a lipid?
2. How can you distinguish between a lipid and carbohyrate?
Give 3 functions for lipids in your body.
4. Lipids provide more energy than carbs, but your body doesn’t use lipids as the main source of energy. Why?