1. Molecules of Life Section 3.3

2. What do we know?
What elements do the symbols C, H, O, and N represent?
In your group, Write the names of these elements on a piece of paper. Then list as many things (both living and nonliving) as you can that contain each element.

3. Organic Compounds
Organic Compounds- almost all compounds containing carbon.
Living things also contain inorganic compounds (do not contain carbon).
Four groups of organic compounds are important to living things:
Carbohydrates
Proteins
Nucleic Acids
Lipids

4. Proteins Made up of long chains of amino acids Cells use proteins to:
Amino Acid- simple molecules that contain C, O, H, and N. (20 different amino acids)
Specific amino acid and their arrangement determine the shape of the protein.
Cells use proteins to:
Build and repair body parts
Speed up chemical reactions
Protect the body from disease
Human body contains more than 100,000 different types of protein molecules, each with its own function.

5. Carbohydrates Most living things use carbohydrates to store energy.
Made up of: Carbon, Hydrogen, and Oxygen atoms.
Two classes of Carbohydrates:
Starches (complex carb. molecules)
Sugars (simple carb. Molecules)
Sugars and starches are broken down into simple sugars in living things.
Simple sugars- (glucose) provide fuel for energy.

6. Lipids Contain: Carbon, Hydrogen, and Oxygen
Lipids do no mix with water.
Three types of lipids: fats, oils, and waxes.
Body uses lipids for energy storage, drawing on them when carbohydrates are not available.
Lipids can contain twice the amount of energy as the same amount of carbohydrate.

7. Nucleic Acids
Large organic molecules that store and process the information the cell needs to carry out its activities.
Stored information is copied and passed along to new generations.
Two types: DNA and RNA
DNA stores the information
RNA-where DNA is copied to be transported to other parts of the cell.

8. What have we learned?
What are organic compounds? Name and describe three types of organic compounds.
Why are nucleic acids important to living things?
What might happen if you did not eat enough foods high in carbohydrates?
Decide if the following substances contain carbon compounds. Explain your conclusions.
Water
Ketchup
Apple
Table salt
Sand
Butter