2. The Chemistry of Carbon BUILDING BLOCKS OF LIFE

3. Why study Carbon? All life (on our planet) is carbon-based Cells ◦~72% H 2 O ◦~25% carbon compounds ◦Carbohydrates ◦Lipids ◦Proteins ◦Nucleic acids ◦~3% salts ◦Na, Cl, K ….

4. Organic Chemistry The study of carbon compounds C atoms are versatile building blocks ◦4 stable covalent bonds HH C H H

6. Hydrocarbons Combinations of C & H ◦Nonpolar ◦Not soluble in H 2 O ◦Hydrophobic ◦Stable ◦Very little attraction between molecules methane (simplest HC)

7. Hydrocarbons can grow …

8. Isomers Molecules with same molecular formula, but different structures ◦Different chemical properties ◦Different biological functions 6 carbons It’s the same, but different

9. Form affects function Structural differences create important functional significance ◦Amino acid alanine ◦L-alanine used in proteins ◦D-alanine is not ◦Medicine ◦L-alanine is active ◦D-alanine is not ◦Sometimes with tragic results stereoisomers

10. Form affects function Thalidomide ◦Prescribed to pregnant women in 50s & 60s ◦Reduced morning sickness, but … ◦Stereoisomer caused severe birth defects Control isomer in production? Evidence shows that body pH can cause racemizing

11. Functional groups generate diversity of molecules Substitute other atoms or groups around the carbon ◦Ethane vs ethanol ◦H replaced by an –OH ◦Nonpolar becomes polar ◦Gas becomes liquid ◦Different biological effects! ethane (C 2 H 6 ) ethanol (C 2 H 5 OH)

12. Functional groups Parts of organic molecules that are involved in chemical reactions ◦Give organic molecules distinctive properties ◦hydroxyl ◦carbonyl ◦carboxyl Affect reactivity ◦Makes hydrocarbons hydrophilic ◦Increases solubility in water ◦amino ◦sulfhydryl ◦phosphate

13. It makes a difference! Basic structure of male & female hormones is identical ◦Identical carbon skeleton ◦Attachment of different functional groups ◦Interact with different targets in the body ◦Different effects

14. Hydroxyl -OH ◦Organic compounds with OH = alcohols ◦Names typically end in –ol ◦ethanol

15. Carbonyl C=O ◦O double bonded to C ◦If C=O at end of molecule = aldehyde ◦If C=O in middle of molecule = ketone

16. Carboxyl -COOH ◦C double bonded to O & single bonded to OH group ◦Compounds with COOH = acids ◦Fatty acids ◦Amino acids

17. Amino -NH 2 ◦N attached to 2 H ◦Compounds with NH 2 = amines ◦Amino acids ◦NH 2 acts as a base ◦Ammonia picks up H+ from solution

18. Sulfhydryl -SH ◦S bonded to H ◦Compounds with SH = thiols ◦SH groups stabilize the structure of proteins

19. Phosphate -PO4 ◦P bonded to 4 O ◦Connects to C through an O ◦Lots of O = lots of negative charge ◦Highly reactive ◦Transfers energy between organic molecules ◦ATP, GTP, etc Becomes important with Gel electrophoresis

20. Macromolecules The Building Blocks of Life

21. Macromolecules Smaller organic molecules join together to form larger molecules 4 major classes of macromolecules: ◦Carbohydrates ◦Lipids ◦Proteins ◦Nucleic acids

22. Polymers Long molecules built by linking repeating building blocks in a chain ◦Monomers ◦Building blocks ◦Repeated small units ◦Covalent bonds ◦Strong ◦Can store energy H2OH2O HO H HH Dehydration synthesis

23. How to build a polymer H2OH2O HO H HH Synthesis ◦Joins monomers by “taking” H 2 O out ◦One monomer donates –OH ◦One monomer donates H ◦Together these form H 2 O ◦Requires energy & enzymes ◦Called dehydration synthesis, condensation reaction, or anabolic reaction enzyme It requires energy to form bonds

24. How to break down a polymer Digestion ◦Use H 2 O to breakdown polymers ◦Reverse of dehydration synthesis ◦Remove one monomer at a time ◦H 2 O is split into H and OH ◦Requires enzymes ◦Releases energy ◦Called hydrolysis, digestion, or catabolic reaction H2OH2O HOH H H enzyme Breaking up is hard to do!

25. Any Questions?

26. Homework Compare the thermal properties of water with those of methane list, t-chart, venn diagram ….