1. The Building Blocks of Life
Section 6.4
The Building Blocks of Life

2. Objectives
Distinguish among proteins, carbohydrates, lipids and nucleic acids. (SPI )
Summarize the four major families of biological macromolecules
Describe the role of carbon in living organisms
Compare the functions of each group of biological macromolecules.
Identify positive tests for carbohydrates, lipids and proteins (SPI )

3. New Vocabulary organic compound macromolecule polymer carbohydrate
lipid
protein
amino acid
nucleic acid
nucleotide
buffer

4. *Carbon – *Hydrogen – *Nitrogen – *Oxygen
Key Elements
*Carbon – *Hydrogen – *Nitrogen – *Oxygen
Phosphorus – Sulfur
* Most common elements in biological systems
* About 95% of your body weight.

5. Inorganic molecules
Do not contain carbon and hydrogen together. Play important roles in biological systems.

6. Organic molecules
Carbon (skeleton) bonded to other atoms (functional groups). They determine the structure and function of living things.

7. Cells are 70-90% water
The degree to which organic molecules interact with water affects their function.

8. What characteristics of an organic molecule do you think affect its interaction with water?

9. Polarity
- Polar molecules (with +/- charges) are attracted to water molecules and are hydrophilic.
- Nonpolar molecules are repelled by and do not dissolve in water and are hydrophobic.
- Hydrocarbons are hydrophobic except when they have an attached ionized functional group such as carboxyl (acid) (-COOH); then the molecule is hydrophilic.

10. Carbon Is Unique
* Four electrons in outer shell; bonds with up to four other atoms (Usually H, O, N, or other carbons).
* Can bond to itself making chains and rings (back bones of organic molecules).
* Characteristics allow it to form an enormous variety of organic molecules.

11. CARBON ATOM

13. Polymers
Macromolecules composed of three to millions of monomer subunits.

14. What is a Polymers?
SMALL ORGANIC MOLECULES (e.g. monosaccharides, glycerol and fatty acids, amino acids, and nucleotides) serve as monomers, the subunits of polymers.

15. What is a Macromolecule?
The four types of large molecules comprising living things
Carbohydrates (Polysaccharides)
Lipids (Triglycerides)*
Proteins (Polypeptides)
Nucleic Acids
* Not polymers

16. Proteins Functions Monomers Polymers Form cell structures
Chemical messengers Enzymes
Body defense
Regulation
Movement & support
Monomers
amino acids
Polymers
Polypeptides
Proteins

17. Carbohydrates Functions Monomers Polymers Energy Cell structures
Cell recognition
Used to make other molecules
Monomers
Monosaccharides(sugars)
Polymers
Poly-saccharides

18. Lipids Functions Components Types Energy storage Membrane Structure
Chemical messengers
Components
Fatty acids, glycerol
Types
Triglycerides (Fats & Oils)
Phospholipids
Waxes
Steroids

19. Nucleic Acids Function Monomers Polymers
Storage & transfer of genetic information
Energy transfer
Monomers
Nucleotides
Polymers
Nucleic acids

20. Building a Polymer (Dehydration Synthesis)
Polymers (carbohydrates, fats, proteins and nucleic acids) are built by bonding monomers together.
The joining is called dehydration synthesis. (Sometimes condensation).
REMOVE WATER!

21. Building a Polymer Chain
(Remove water!)

22. Dehydration synthesis

23. Breaking Down A Polymer (Hydrolysis)
Hydrolysis means to split with water.
“water” (hydro–)
“split” (–lysis)
ADD WATER!

24. Breaking a Polymer Chain
(Add Water!)

25. Hydrolysis reaction breaks down polymers
Hydrolysis reaction breaks down polymers. The reverse of dehydration synthesis.

26. Catalyze condensation and hydrolysis of polymers. SPEED UP REACTIONS!
Enzymes
Catalyze condensation and hydrolysis of polymers.
SPEED UP REACTIONS!

27. Let’s Review
Compare and contrast characteristics and significance of organic vs. inorganic molecules.
List the four types of polymers of biological significance
List the building blocks (monomers) that form the four types of polymers of biological significance.
Describe dehydration synthesis
Describe hydrolysis.