2. AP Biology AP Biology John D. O’Bryant School of Mathematics and Science September 12, 2012

3. AP Biology Agenda  Do Now (Quiz)  Macromolecules (review)  The Occurrence of Water in Living Things  Qualitative Tests of Biological Macromolecules

4. AP Biology Do Now (Quiz)  1. Used to carry the genetic code  (A)Proteins  (B) Carbohydrates  (C) Nucleic acids  (D)Lipids  (E) Steroids

5. AP Biology Do Now (Quiz)  2. Synthesized at the ribosome  (A)Proteins  (B) Carbohydrates  (C) Nucleic acids  (D)Lipids  (E) Steroids

6. AP Biology Do Now (Quiz)  3. Includes glycogen, chitin, cellulose, and glucose  (A)Proteins  (B) Carbohydrates  (C) Nucleic acids  (D)Lipids  (E) Steroids

7. AP Biology Do Now (Quiz)  4. Used for insulation and buoyancy in marine Arctic animals  (A)Proteins  (B) Carbohydrates  (C) Nucleic acids  (D)Lipids  (E) Steroids

8. AP Biology The Occurrence of Water in Living Things  1. All living organisms consist mostly of water.  2. The adult human body is about 60% water, by weight, and 75% by volume.  3. As much as 95% of the weight of some plants is due to the water they contain.  Experimental Question: ________________________________________   Hypothesis: ___________________________________________________________   Materials Available:   Triple beam balance Grass Assorted vegetables  Incubator   Procedure:  ____________________________________________________________________

9. AP Biology Classwork 1. Draw the electron-shell diagrams of the following: a. water b. carbon dioxide c. methane d. hydrogen sulfide 1. Illustrate electron transfer and ionic bonding in sodium chloride. 2. Compare and contrast atomic number and atomic mass. 3. Oxygen has 6 electrons in its outermost shell. How many covalent bonds can an atom of oxygen form? 4. Explain why the noble gases are unreactive. 5. What is a buffer? What makes them important? 6. Illustrate a dehydration reaction between two amino acids. 7. Illustrate a hydrolytic reaction in a disaccharide.

10. AP Biology Polysaccharide diversity  Molecular structure determines function  isomers of glucose  structure determines function… in starchin cellulose

11. AP Biology Digesting starch vs. cellulose starch easy to digest enzyme cellulose hard to digest only bacteria can digest

12. AP Biology Cellulose  Most abundant organic compound on Earth  herbivores have evolved a mechanism to digest cellulose  most carnivores have not  that’s why they eat meat to get their energy & nutrients  cellulose = undigestible roughage But it tastes like hay! Who can live on this stuff?!

13. AP Biology Cow can digest cellulose well; no need to eat other sugars Gorilla can’t digest cellulose well; must add another sugar source, like fruit to diet

14. AP Biology Helpful bacteria  How can herbivores digest cellulose so well?  BACTERIA live in their digestive systems & help digest cellulose-rich (grass) meals Ruminants Tell me about the rabbits, again, George! I eat WHAT! Caprophage

15. AP Biology 2010- 2011 Let’s build some Carbohydrates! EAT X

16. AP Biology Lipids: Fats & Oils

17. AP Biology 2006- 2007 Lipids long term energy storage concentrated energy

18. AP Biology Lipids  Lipids are composed of C, H, O  long hydrocarbon chains (H-C)  “Family groups”  fats  phospholipids  steroids  Do not form polymers  big molecules made of smaller subunits  not a continuing chain

19. AP Biology Fats  Structure:  glycerol (3C alcohol) + fatty acid  fatty acid = long HC “tail” with carboxyl (COOH) group “head” dehydration synthesis H2OH2O enzyme

20. AP Biology Building Fats  Triacylglycerol  3 fatty acids linked to glycerol  ester linkage = between OH & COOH hydroxylcarboxyl

21. AP Biology Dehydration synthesis dehydration synthesis H2OH2OH2OH2OH2OH2OH2OH2O enzyme

22. AP Biology Fats store energy  Long HC chain  polar or non-polar?  hydrophilic or hydrophobic?  Function:  energy storage  concentrated  all H-C!  2x carbohydrates  cushion organs  insulates body  think whale blubber! Why do humans like fatty foods?

23. AP Biology Saturated fats  All C bonded to H  No C=C double bonds  long, straight chain  most animal fats  solid at room temp.  contributes to cardiovascular disease (atherosclerosis) = plaque deposits

24. AP Biology Unsaturated fats  C=C double bonds in the fatty acids  plant & fish fats  vegetable oils  liquid at room temperature  the kinks made by double bonded C prevent the molecules from packing tightly together mono-unsaturated? poly-unsaturated?

25. AP Biology Saturated vs. unsaturated saturatedunsaturated

26. AP Biology Phospholipids  Structure:  glycerol + 2 fatty acids + PO 4  PO 4 = negatively charged It’s just like a penguin… A head at one end & a tail at the other!

27. AP Biology Phospholipids  Hydrophobic or hydrophilic?  fatty acid tails =  PO 4 head =  split “personality” interaction with H 2 O is complex & very important! “repelled by water” “attracted to water” Come here, No, go away! hydrophobic hydrophillic

28. AP Biology Phospholipids in water  Hydrophilic heads “attracted” to H 2 O  Hydrophobic tails “hide” from H 2 O  can self-assemble into “bubbles”  bubble = “micelle”  can also form a phospholipid bilayer  early evolutionary stage of cell? bilayer water

29. AP Biology Why is this important?  Phospholipids create a barrier in water  define outside vs. inside  they make cell membranes! Tell them about soap!

30. AP Biology Steroids  Structure:  4 fused C rings + ??  different steroids created by attaching different functional groups to rings  different structure creates different function  examples: cholesterol, sex hormones cholesterol

31. AP Biology Cholesterol  Important cell component  animal cell membranes  precursor of all other steroids  including vertebrate sex hormones  high levels in blood may contribute to cardiovascular disease

32. AP Biology Cholesterol helps keep cell membranes fluid & flexible Important component of cell membrane

33. AP Biology From Cholesterol  Sex Hormones  What a big difference a few atoms can make!

34. AP Biology 2006- 2007 Let’s build some Lipids!

35. AP Biology 2007- 2008 Ghosts of Lectures Past (storage)

36. AP Biology Phospholipids & cells  Phospholipids of cell membrane  double layer = bilayer  hydrophilic heads on outside  in contact with aqueous solution outside of cell and inside of cell  hydrophobic tails on inside  form core  forms barrier between cell & external environment Tell them about soap!