Chapter 2: The Chemistry of Life

1. Chapter 2: The Chemistry of Life Section 2.2: The Compounds of Life

2. Objective: • 3.3.10A Explain the structural and functional similarities and differences found among living things. • 3.3.10B Describe and explain the chemical and structural basis of living organisms

3. Carbon • Can form 4covalent bonds. • Bonds – short and strong; can form long, stable chains. • Can form bonds with other carbon (C) atoms, hydrogen (H), oxygen (O), nitrogen (N), phosphorus (P) and other elements.

4. NO element matches carbon in forming chains of different shapes, sizes and complexity.

5. Organic compounds contain at least 2 C atoms (with some exceptions). • All other compounds are inorganic compounds.

6. Sub-Objective: • Define macromolecule. • Identify the 4 major classes of macromolecules.

7. Macromolecules: • Monomers, meaning single units, are small molecules. • Polymers, meaning many units, are assembled by combining monomers to form large molecules. • Macromolecules, meaning giant molecules, are verylarge polymers.

8. 4 Major Macromolecules • Carbohydrates

9. Carbohydrates • Include sugar and starches • Composed of C, H, and O. • Generally contain 2 H atoms for every O atom. • Short term storage of energy and structural components of some cells.

10. Three Types of Carbohydrates • Monosaccharides –simple sugars (one unit).

11. Monosaccharides • Lactose - found in milk. • Fructose – found in fruit. • Glucose – found in the cells of every organism. • They are isomers - All have the same formulaC6H12O6, but each has a slightly different arrangement of its atoms.

12. Three Types of Carbohydrates • Monosaccharides –simple sugars (one unit). • Disaccharides – 2 simple sugars bonded together.

13. Disaccharides • Sucrose – table sugar • Lactose – milk sugar • Maltose – malt sugar • The above are isomers of each other. C12H22O11

14. Three Types of Carbohydrates • Monosaccharides –simple sugars (one unit). • Disaccharides – 2 simple sugars* bonded together. • Polysaccharides - many monosaccharides bonded together.

15. Polysaccharide • Starch – storage form of energy for plants. • Glycogen – storage form of energy for animals. • Cellulose – structural component of plant cells. • Chitin – structural component of exoskeletons and fungi.

16. Lipids • Made from C, O and H. • Waxy, fatty or oily compounds. • Long-term storage of energy. • Oils and fats: * Composed of fatty acid chains and a glycerol backbone. * Act as insulators and cushions.

17. Lipids • Waxes: * Different backbone than oils and fats. * Act as waterproofing materials for plants and animals.

18. Lipids • Phospholipids * Composed of fatty acid chains, a glycerol backbone and a phosphate group. * Forms the structural basis of cell membranes.

19. Lipids • Sterols * Series of carbon rings. * Important role in building cells and carrying messages in the body. * Cholesterol and steroid hormones.

20. Proteins • Polymers of amino acids (20 common amino acids). • Amino acids are composed of: * Central carbon atom * Hydrogen atom * Amino group (-NH2) * Carboxyl group (-COOH) * An R group

21. Protein • The R group is what makes each amino acid different. • Amino acids join between the amino and carboxyl groups to form a peptide bond. • Chain of amino acids = polypeptide.

22. Proteins • Principal components of feathers, skin and muscles. • Help chemical reactions to proceed (enzymes). • Pump small molecules in and out of cells.

23. Nucleic Acids • Information carrying molecules. • DNA and RNA • Assembled from nucleotides.

24. Nucleic Acids • Nucleotides consist of: * Phosphate group * Nitrogen base * 5-C sugar either deoxyribose (DNA) or ribose (RNA). * 4 different nucleotides in both DNA and RNA. * Arrangement of the nucleotides determines the information that the nucleic acid contains.

26. ATP • Temporary energy storage in cells. • Composed of nucleotides