2. AP Biology Chemistry of Carbon Building Blocks of Life

3. AP Biology 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…

4. AP Biology Chemistry of Life  Organic chemistry is the study of carbon compounds  C atoms are versatile building blocks  bonding properties  4 stable covalent bonds

5. AP Biology  Forms strong covalent bonds because it has 4 valence shell electrons  Not likely to donate or gain 4 electrons to form ionic bonds  Makes 4 covalent bonds with other atoms which allows it to make large complex molecules  H, O, N are its most common partners

6. AP Biology Complex molecules assembled like TinkerToys

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

8. AP Biology Hydrocarbons can grow

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

10. AP Biology Structural Isomers  Differ in the covalent arrangements of their atoms

11. AP Biology Geometric isomers  Have same covalent partners but differ in their spatial arrangments  Usually involve a double bond which is inflexible and cannot be rotated freely with other atoms

12. AP Biology Enantiomers  Mirror images of each other  Important to pharmaceutical industry  Two enantiomers of a drug may not be equally effective, sometimes the effect can actually be harmful

13. AP Biology Form affects function  Structural differences create important functional significance  amino acid alanine  L-alanine used in proteins  but not D-alanine  Parkinson’s medicine  L-version active  but not D-version  sometimes with tragic results… stereoisomers

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

15. AP Biology Functional groups  Attachments to hydrocarbon that replace one or more of the H bonds to the carbon skeleton  They are the parts of organic molecules that are involved in chemical reactions  give organic molecules distinctive properties hydroxyl amino carbonyl sulfhydryl carboxyl phosphate n methyl  Affect reactivity  makes hydrocarbons hydrophilic  increase solubility in water

16. AP Biology 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

17. AP Biology Hydroxyl  –OH  organic compounds with OH = alcohols  names typically end in -ol  ethanol

18. AP Biology Example  C2H6 vs. C2H5OH  ethane vs. ethanol  H replaced by an hydroxyl group (–OH)  nonpolar vs. polar  gas vs. liquid ethane (C 2 H 6 ) ethanol (C 2 H 5 OH)

19. AP Biology Carbonyl  C=O  O double bonded to C  if C=O at end molecule = aldehyde  if C=O in middle of molecule = ketone

20. AP Biology Carboxyl  –COOH  C double bonded to O & single bonded to OH group  compounds with COOH = acids  fatty acids  amino acids

21. AP Biology Amino  -NH 2  N attached to 2 H  compounds with NH 2 = amines  amino acids  NH 2 acts as base  ammonia picks up H + from solution

22. AP Biology Sulfhydryl  –SH  S bonded to H  compounds with SH = thiols  SH groups stabilize the structure of proteins

23. AP Biology Phosphate  –PO 4  P bound 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.

24. AP Biology Methyl  -CH 3  C bonded to 3 H  Methylation  Process of adding a methyl group to a hydrocarbon  Used for regulation of gene expression and protein function

25. AP Biology 2007-2008 Macromolecules Building Blocks of Life

26. AP Biology Macromolecules  Smaller organic molecules join together to form larger molecules  macromolecules  4 major classes of macromolecules:  carbohydrates  lipids  proteins  nucleic acids

27. AP Biology 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

28. AP Biology 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!

29. AP Biology 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