1. Lipids

2. Aim: What are the building blocks of lipids? Do Now:
Identify the four major groups of organic compounds.
Identify the process in which several monosaccharides form a polysaccharide (or disaccharide) chain of sugars? What is added/removed during this process?
What two types of atoms are always found in organic substances?

3. Lipids Lipids include waxes, fats, and oils
Fats- solid at room temperature
Oils- liquid at room temperature.

4. Lipids Atoms found in lipids:
Carbon (C), Hydrogen (H), and Oxygen (O) atoms are found in all lipids.
Lipid atom ratio: 1C: 4H:1 O
Nonpolar (will not mix with H2O)
Q: Which other organic compound is made up of C, H, and O atoms?
Carbohydrates!

5. Building Blocks
Fatty acids
Glycerol
Glycerol

6. Functions Within Organisms
Energy storage
Lipids store 2x as much energy as carbohydrates.
Insulation and protection
Fatty tissue cushions vital organs and helps insulate the body.
Cell structure
Phospholipid Bilayer
Weddell Seal

7. Phospholipids 2 fatty acids + 1 glycerol molecule
Cell membrane consists of 2 layers of phospholipids (lipid bilayer).
Forms a barrier (semi-permeable membrane)

8. Fatty Acids
Long unbranched carbon chains with a carboxyl (-COOH) at one end.
COOH = polar/hydrophilic
Hydrocarbon end = nonpolar/hydrophobic
Make up most lipids
Saturated- each C has 4 covalent bonds with 4 other atoms.
Unsaturated- C atoms are not bonded to 4 atoms. Instead, they form C=C bonds.

9. Triglycerides
Consist of three fatty acid molecules + 1 molecule of glycerol.
Saturated triglycerides- contain saturated fatty acids
Unsaturated- do not
High melting points
Saturated- Usually solid at room temperature (Ex: butter and fats in red meat).
Unsaturated- usually soft or liquid at room temperature.

10. Energy Storage
When food is scarce: animals break down fat molecules to release energy for life processes.
When food is plentiful: excess food is converted into fats for LONG-TERM energy storage in animals.
Plants: oils are stored in seeds to provide energy to start the growth of the new plant.

11. Water Barriers Phospholipids Waxes- Hydrophobic region (water fearing)
Hydrophilic region (water loving)
Waxes-
thin layer covers stems and leaves of plants to prevent evaporation of water from plant cells.
Some birds coat their feathers in oil. Why?

12. Dehydration Synthesis
Animation

15. The End!

16. STOP