From Chemistry to Cells

1. From Chemistry to Cells Chapter 7

2. But first, the Barriers (Cell membranes)

3. Phospholipid Bilayer

4. How to get across? • Some items can’t – they’re too big • Endocytosis = swallowed by the cell • Diffuse across – some small molecules slip through the membrane • Transport • Through tunnels • Pumped across Both require protein help

5. Diffusion (Concentration Gradient) Remember, equilibrium does not mean static, the solutes still move but in approximately equal amounts

6. Osmosis = diffusion of water

7. Here’s the actual lab set up Water slips through the membrane through proteins and will end up equalizing the amount of water on both sides of the membrane. This can be good or bad, depending on the situation. So in this case the solvent moves but not the solute – this requires NO energy from the cell

8. Boom

9. Facilitated Diffusion Active transport Transport – to ATP or not to ATP?

10. Types of active transport

11. What about the Cells themselves?

12. In the Beginning… • 1665 Robert Hooke is credited with giving cells their name • Observed cork, which comes from tree bark

13. An egg is not a single cell but it can be used as a comparison • Note that large organelles are just barely visible using a light microscope.

14. Don’t Forget… • Anton von Leeuwenhoek • Credited with observing “animalcules”

15. Cell Theory • Schleiden, Schwann, and Vichow • All living things are made up of cells • Cells are the basic units of structure and function • New cells are produced from existing cells (Biogenesis)

16. What is a Cell? • Unit of living matter • Cell membrane • DNA, RNA and proteins • Undergoes chemical reactions in a set manner – life • reproduces

17. Prokaryote vs. Eukaryote

18. Basic Cell - Prokaryote There are only 4 parts -How is this cell able to survive?

19. Prokaryote vs. Eukaryote • “Before kernel” vs. “true kernel” • Eukaryotes: • Have membrane bound organelles • Tend to be larger • Can truly be multicellular • Prokaryotes: • Don’t

20. Divisions of a Eukaryote

21. Divisions of a Eukaryote

22. Nucleus

23. Endoplasmic Reticulum • Smooth vs. Rough • Connected to the nucleus • May be part of the membrane • Protein factory • Membrane bound proteins • Proteins going to other organelles

24. Ribosomes • Machines that make proteins • 2 subunits that wrap around mRNA • mRNA  AA  protein • May be free or membrane bound (ER)

25. Golgi Apparatus (Bodies) • Gets proteins from ER • Modifies, sorts and packages • Distribution center

27. Distribution: either out of the cell or to another organelle

28. Mitochondria • Power house of the cell • Produces ATP • 2 membranes • Own DNA • Own Ribosomes • Own Enzymes

29. What is the logical explanation for this 15% difference In mitochondrial dist.?

30. Vacuoles – Plant cells

31. Vacuoles – Animal cells

32. Why the small package? • Why not keep growing – why divide? • Surface area to Volume ratio • Too much volume, too little space for it to get in • Diffusion happens at the same rate, but smaller volume means less dist. to travel.

33. Surface Area (cube) 1 cm2 6 cm2 total 2 cm2  24 cm2 total 3 cm2  54 cm2 total 4 cm2  96 cm2 total 5 cm2 150 cm2total Volume (cube) 1 cm3 1cm3 total 2 cm3  8 cm3 total 3 cm3 27 cm3total 4 cm3 64 cm3total 5 cm3 125cm3total What does it all mean? Sooooooo ………??

34. Look at the ratio … Surface Area to Volume 6:1 3:1 2:1 Etc. Etc. Etc.

35. Therefore… • They HAVE to be small to be able to get all of the good stuff in and to get all of the bad stuff out • Even with the help of organelles there is a limit to how big and it is dependant on the diffusion rate

36. Remember the Mitochondria? • 2 membranes • Own DNA etc. • Thought of as a cell inside a cell • Endosymbiosis Theory

37. Endosymbiosis Theory A B Membrane – same as that of cell A Membrane – same as that of cell B

38. Chloroplasts • Possibly arose the same way • Have multiple membranes • Own DNA • Own Ribosomes and Enzymes • Reproduce on their own

40. Don’t forget Lysosomes – the garbage men of the cell

41. How does it get around? • Cytoskeleton • Acts as a rail system inside the cell • Actually attached to the microtubes, which are shortened / lengthened

42. Cellular Respiration Chapter 9

43. Here’s what you need to focus on (yes I would write this down) • What’s the point? • What are the 2 steps and what is the difference in the 2 poss. outcomes for #2? • How (generally) does it work, in other words where do the H ions come from and how does this lead to the ATP Synthase? • How does this compare to the other options?

44. It All Begins in the Cytoplasm • Cellular Respiration is made up of… • Glycolysis (breakdown of Glucose) • Fermentation (when there’s no O2), or • Krebs cycle (when there IS O2) • Glycolysis occurs here in the cytoplasm • Fermentation is in the cytosol • Krebs cycle is in the mitochondria

45. Glycolysis Fermentation Krebs Cycle And Electron transport Image adapted from http://www.sirinet.net/~jgjohnso/respiration.html

46. Remember Glucose 6 Carbons (C6H12O6) gets broken down to 2 – 3 Carbon molecules

48. Lets get Aerobic Image adapted from http://www.sirinet.net/~jgjohnso/respiration.html

49. What Does it all Mean !?!? • For every 1 glucose you get ~36 ATP • Most of this comes from NADH and FADH2 • These utilize the electron transport chain

50. H+ H+ H+ H+ H+ H+ H+ H+ ATP H+ H+ H+ H+ Remember the mitochondria? • H+ ions are put in the intermembrane space and then allowed to pour through • This kinetic motion is used to make ATP