1. AP Biology Objective: SWBAT explain the role of carbon in the molecular diversity of life and identify the functional groups that determine the properties of organic compounds 1. Briefly explain how Water Striders (“Jesus bugs”) are able to walk on water using the properties of water learned last class 1. Which of the following is a correct statement about the relationship between pH and the hydrogen-ion concentration of a solution? A. There are no hydrogen ions present in a solution with a basic pH. B. There are no hydrogen ions present in a solution with a neutral pH of 7.0. C. The concentration of hydrogen ions in a solution with a pH of 7.0 is 100 times as great as that in a solution with a pH of 9.0. D. The concentration of hydrogen ions in a solution with a pH of 5.0 is twice that in a solution with a pH of 3.0. E. The concentration of hydrogen ions in a solution with a pH of 4.0 is 400 times as great as that in a solution with a pH of 1.0.

2. AP Biology ANNOUNCEMENTS  Look over Carbon Compounds and function groups  Mini quiz tomorrow morning

3. AP Biology Unit 1: Chemistry of Life Chapter 3 – Introduction to Organic Compounds

4. AP Biology 2003-2004 Why study Carbon?  All living things are made of cells  Cells  ~70-95% water, the rest consists of carbon compounds  carbohydrates  lipids  proteins  nucleic acids

5. AP Biology 2003-2004 Chemistry of Life  Organic chemistry is the study of carbon compounds  C atoms are versatile building blocks  bonding properties  4 stable covalent bonds

6. AP Biology  The electron configuration of carbon gives it compatibility to form covalent bonds with many different elements. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 4.3

7. AP Biology 2003-2004 Complex molecules assembled like TinkerToys

8. AP Biology 2003-2004 Hydrocarbons  Simplest C molecules = hydrocarbons  combinations of carbon atoms attached to hydrogens  Simplest HC molecule = methane  1 carbon bound to 4 H atoms  non-polar  not soluble in H 2 O  hydrophobic  stable  very little attraction between molecules  a gas at room temperature

9. AP Biology 2003-2004 Hydrocarbons can grow (Carbon Skeleton)  adding C-C bonds  straight line  ethane  hexane  branching  isohexane  ring  cyclohexane ethane hexane cyclohexane isohexane methane

10. AP Biology Variation in carbon skeletons contributes to the diversity of organic molecules Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

11. AP Biology 2003-2004 Diversity of organic molecules

12. AP Biology 2003-2004 Isomers  Molecules with same molecular formula but different structures  different chemical properties

13. AP Biology 2003-2004 Structural isomers  Molecules differ in structural arrangement of atoms

14. AP Biology 2003-2004 Geometric isomers  Molecules differ in arrangement around C=C double bond  same covalent partnerships

15. AP Biology 2003-2004 Enantiomer (stereo) isomers  Molecules which are mirror images of each other  C bonded to 4 different atoms or groups  assymetric  left-handed & right-handed versions

16. AP Biology 2003-2004 Form affects function  Structural differences create important functional significance  amino acid alanine  L-alanine used in proteins  but not D-alanine  medicines  L-version active  but not D-version  sometimes with tragic results…

17. AP Biology 2003-2004 Form affects function  Thalidomide  prescribed to pregnant women in 50’s & 60’s  reduced morning sickness, but…  stereoisomer caused severe birth defects

18. AP Biology 2003-2004 Functional Groups

19. AP Biology 2003-2004 Functional groups  Components of organic molecules that are involved in chemical reactions  give organic molecules distinctive properties  ex: male & female hormones…

20. AP Biology 2003-2004 Viva la difference!  Basic structure of male & female hormones is identical  identical C skeleton  attachment of DIFFERENT FUNCTIONAL GROUPS  interact with different targets in the body

21. AP Biology 2003-2004 Types of functional groups  6 functional groups most important to chemistry of life:  hydroxyl u amino  carbonyl u sulfhydryl  carboxyl u phosphate  Affect reactivity  hydrophilic  increase solubility in water

22. AP Biology 2003-2004 Hydroxyl  –OH  organic compounds with OH = alcohols  names typically end in -ol  ethanol

23. AP Biology 2003-2004 Carbonyl  C=O  O double bonded to C  if C=O at end molecule = aldelhyde  if C=O in middle of molecule = ketone

24. AP Biology 2003-2004 Carboxyl  –COOH  C double bonded to O & single bonded to OH group  compounds with COOH = acids  fatty acids  amino acids

25. AP Biology 2003-2004 Amino  -NH 2  N attached to 2 H  compounds with NH 2 = amines  amnio acids  NH 2 acts as base  ammonia picks up H + from solution

26. AP Biology 2003-2004 Sulfhydryl  –SH  S bonded to H  compounds with SH = thiols  SH groups stabilize the structure of proteins

27. AP Biology 2003-2004 Phosphate  –PO 4  P bound to 4 O  connects to C through an O  PO 4 are anions with 2 negative charges  function of PO 4 is to transfer energy between organic molecules (ATP)

28. AP Biology 2003-2004 Why study Functional Groups?  These are the building blocks for biological molecules …and that comes next!

29. AP Biology  Living matter consists mainly of carbon, oxygen, hydrogen, and nitrogen, with smaller amounts of sulfur and phosphorus.  These elements are linked by strong covalent bonds.  Carbon with its four covalent bonds is the basic building block in molecular architecture.  The great diversity of organic molecules with their special properties emerge from the unique arrangement of the carbon skeleton and the functional groups attached to the skeleton. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

30. AP Biology 2003-2004 Any Questions??