2. Chemistry of Carbon Building Blocks of Life Chapter 4

3. Chemistry of Life  Organic chemistry is the study of carbon compounds  C atoms are versatile building blocks  4 stable covalent bonds- tetravalent HH C H H

4. Carbon and Multiple Bonding  It can share four pairs of electrons in four covalent bonds.  Carbon atoms can also form multiple bonds with other atoms including other carbon atoms.

5. Why study Carbon?  All of life is built on carbon  Cells  ~72% H 2 O  ~25% carbon compounds  carbohydrates  lipids  proteins  nucleic acids  ~3% salts  Na, Cl, K…

6. The Most Important Elements  CHONPS!  Six most abundant elements of life  What are they?  What are they used for?  Structures, enzymes, energy, hormones, DNA, RNA…  How do we get them?  Eating, drinking, breathing…

7. Hydrocarbons  Combinations of C & H  non-polar  not soluble in H 2 O  hydrophobic  stable  very little attraction between molecules  a gas at room temperature methane (simplest HC)

8. Isomers  Molecules with same molecular formula but different structures (shapes)  different chemical properties  different biological functions 6 carbons

9. Isomers  Types of isomers 1. structural2. geometric Different structuredifferent spatial arrangement

10. Sterioisomers or Enantiomers  Structural differences create important functional significance  amino acid alanine  L(levo)-alanine used in proteins  but not D(dextro)-alanine  medicines  L-version active  but not D-version  sometimes with tragic results…

11. Form affects function  Thalidomide  prescribed to pregnant women in 50s & 60s  reduced morning sickness, but…  stereoisomer caused severe birth defects

12. Fig. 4-8 Drug Ibuprofen Albuterol Condition Pain; inflammation Asthma Effective Enantiomer S-Ibuprofen R-Albuterol R-Ibuprofen S-Albuterol Ineffective Enantiomer

13. Viva la 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. Macromolecules  Smaller organic molecules join together to form larger molecules  macromolecules  4 major classes of macromolecules:  carbohydrates  lipids  proteins  nucleic acids

15. H2OH2O HO H HH Polymers  Long molecules built by linking repeating building blocks in a chain  monomers  building blocks  repeated small units  covalent bonds Dehydration synthesis

16. H2OH2O HO H HH How to build a polymer  Synthesis  joins monomers by “taking” H 2 O out  one monomer donates OH –  other monomer donates H +  together these form H 2 O  requires energy & enzymes enzyme Dehydration synthesis Condensation reaction You gotta be open to “bonding!

17. H2OH2O HOH H H How to break down a polymer  Digestion  use H 2 O to breakdown polymers  reverse of dehydration synthesis  cleave off one monomer at a time  H 2 O is split into H + and OH –  H + & OH – attach to ends  requires enzymes  releases energy Breaking up is hard to do! Hydrolysis Digestion enzyme