Lipids

Aim: What are the building blocks of lipids?Do Now:

1. Identify the four major groups of organic compounds.

2. Identify the process in which several monosaccharides form a polysaccharide (or disaccharide) chain of sugars? What is added/removed during this process?

3. What two types of atoms are always found in organic substances?

LipidsLipids include waxes, fats, and oils

LipidsAtoms 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!

Building Blocks1. Fatty acids

2. Glycerol

Glycerol

Functions Within OrganismsEnergy storage

Lipids store 2x as much energy as carbohydrates.

Insulation and protectionFatty tissue cushions vital organs and helps

insulate the body. Cell structure

Weddell SealPhospholipid Bilayer

Phospholipids

2 fatty acids + 1 glycerol moleculeCell membrane consists of 2 layers of

phospholipids (lipid bilayer).Forms a barrier (semi-permeable membrane)

Fatty AcidsLong unbranched carbon chains with a

carboxyl (-COOH) at one end. COOH = polar/hydrophilicHydrocarbon end = nonpolar/hydrophobic

Make up most lipidsSaturated- 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.

TriglyceridesConsist of three fatty acid molecules + 1

molecule of glycerol. Saturated triglycerides- contain saturated fatty

acidsUnsaturated- 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.

Energy StorageWhen 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.

Water BarriersPhospholipids

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?

Dehydration Synthesis

The End!

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