1. Organic Chemistry Basics Chapter 3

2. Organic compounds  Carbon covalently bonded to each other and other atoms  Originally thought only found in living things  Wide diversity in compounds: more than 5 million have been identified  Macromolecules : cells make large molecules from smaller ones

3. Properties of Carbon  4 valence electrons = 4 covalent bonds  Can form bonds with itself  Carbon to carbon bonds are strong but not unbreakable, making them good for structural components  Carbon can also form double and triple bonds with itself  Carbon can form straight or branched chains as well as rings

4. Isomers  Compounds with the same molecular formula but different structures  Do not have identical physical or chemical properties  Three types:  Structural – different covalent arrangement  Geometric – different spatial arrangement  Enantiomers – mirror images of each other

5. Structural isomers Geometric isomers Enantiomers

6. Hydrocarbons  Carbon + hydrogen  Nonpolar  Tend to be hydrophobic  Hydrogen atoms can be replaced with a functional group  Polar and ionic functional groups are hydrophilic

7. Functional groups  Hydroxyl group : R-OH  Alcohols  Carbonyl group : carbon to oxygen double bond  Aldehyde :  R-CHO (at end of C skeleton)  Ketone :  R-CO-R (internal carbonyl group) ethanol

8. Functional groups…  Carboxyl group : R-COOH  Amino group : R-NH 2  Both essential in amino acids  Phosphate group : R-PO 4 H 2  Part of DNA backbone  Sulfhydryl group : R-SH  Thiols – important in proteins

9. Polymers  Formed by linking small organic molecules together  Example: 20 different amino acids form thousands of different proteins  Hydrolysis reactions (‘break with water’)  Breaks apart a polymer  Condensation reactions (‘remove water’)  Joins monomers into a polymer  In biological systems these are regulated by different enzymes.