2. Carbon Cycle

4. Photosynthesis: REVIEW Previously, we learned that photosynthesis takes place in the chloroplasts light reactions In the ‘light reactions’, solar energy is captured by photosystems on the thylakoid membrane and used to attach phosphate groups to energy-carrying molecules like ATP.

5. Photosynthesis: REVIEW ATP NADPHlight reactions In the CALVIN CYCLE (dark cycle), the ATP and NADPH made in the light reactions are used to power the building of sugars in the stroma, the fluid-filled interior of the chloroplasts. This completes the equation for photosynthesis: 6 CO 2 + 6 H 2 0 C 6 H 12 O 6 + 6 O 2

6. Photosynthesis: REVIEW So now we have energy stored in the form of sugars. Very nice, but what if plants (or, for that matter, people) want to release that energy? THEY MUST USE A DIFFERENT PATH…..! This completes the equation for photosynthesis: 6 CO 2 + 6 H 2 0 C 6 H 12 O 6 + 6 O 2

7. CELLULAR RESPIRATION ! Next, we’ll need another organelle to do these chloroplasts reactions in! Not chloroplasts this time, but instead another organelle with its own DNA…. REVERSE FIRST, WE REVERSE THE EQUATION: 6 CO 2 + 6 H 2 0 C 6 H 12 O 6 + 6 O 2

8. What organelle is the powerhouse of cells? Mitochondria!! (only one is a mitochondrion)

9. So what???? How long can you live without food? –~8 weeks if you’re healthy to start How long can you live without water? –~3-5 days if not in excessive heat or cold How long can you live without oxygen? –Minutes! ~5 minutes Why? ATP!! This is the energy your cells can use to do all cellular work like digest and build molecules, contract muscles cells, run the nervous system!!

10. Mitochondria:

11. Mitochondria:

12. have complex folded inner membranes have complex folded inner membranes (cristae), increasing their surface area (cristae), increasing their surface area Mitochondria:

13. have complex folded inner membranes have complex folded inner membranes (cristae), increasing their surface area (cristae), increasing their surface area have a fluid-filled interior (the matrix) have a fluid-filled interior (the matrix) Mitochondria:

14. have complex folded inner membranes have complex folded inner membranes (cristae), increasing their surface area (cristae), increasing their surface area have a fluid-filled interior (the matrix) have a fluid-filled interior (the matrix) act like combustion chambers in an engine, act like combustion chambers in an engine, a ‘safe’ place to ‘burn’ fuel with oxygen a ‘safe’ place to ‘burn’ fuel with oxygen Mitochondria:

15. Before combustion can occur, however, we have to get some “fuel” !

16. What happens when any fuel is combusted? What about a wood fire? Cellulose + oxygen water + carbon dioxide + energy (heat and light) What about fuel in your car or natural gas/oil heat? Hydrocarbon fuel (gas) + oxygen water + carbon dioxide + energy –Energy released is converted to kinetic energy and/or heat What about in living organisms like yourself? Cellular respiration is glucose + oxygen water + carbon dioxide + energy (ATP) + heat (notice that last one? This is how you maintain your body temp. along with gaining ATP energy for your cells)

17. Overall Equation for Cellular Respiration: For that, we will need to break down glucose (or other sugars) OUTSIDE the mitochondria, in a process called....

19. is the breakdown of glucose (or is the breakdown of glucose (or other sugars) other sugars)

20. is the breakdown of glucose (or is the breakdown of glucose (or other sugars) other sugars) requires an activation energy requires an activation energy

21. is the breakdown of glucose (or is the breakdown of glucose (or other sugars) other sugars) requires an activation energy requires an activation energy occurs in the cytoplasm occurs in the cytoplasm

22. Polymers of glucose, like starch, are first broken into individual sugars through hydrolysis

23. The single sugars produced contain stored energy in their chemical bonds, but they are still too big to pass through the mitochondrial membrane.

24. ATP provides the initial activation energy. The 6-carbon sugar will be broken down in a series of steps that do not involve oxygen.

25. There will be a net gain of 2 ATP. The final products of glycolysis are two 3-carbon molecules of pyruvate (pyruvic acid) C3H3O3C3H3O3

26. Pyruvate membrane Pyruvate is small enough to be easily transported through the mitochondrial membrane, where a new series of chemical reactions take place... C3H3O3C3H3O3

27. The Krebs Cycle

28. The Krebs Cycle: takes place in the matrix

29. The Krebs Cycle: takes place in the matrix 3-carbon begins by converting each of the 3-carbon pyruvates into a special complex called acetyl CoA C3H3O3C3H3O3C3H3O3C3H3O3 “acetyl “acetyl CoA”.. Co-enzyme A is added Pyruvate enters the matrix......a waste product, CO 2, is released...

30. The Krebs Cycle: Acetyl CoA begins the cycle Acetyl CoA

31. The Krebs Cycle: Acetyl CoA begins the cycle CO 2 As the cycle proceeds, CO 2 are removed CO 2

32. The Krebs Cycle: There is a net ATP gain in ATP, and... electron transport chain...an electron transport chain is charged! ATP CO 2 e-e-e-e- e-e-e-e-

33. Electron Transport: cristae takes place in the cristae

34. Electron Transport: cristae takes place in the cristae

35. Electron Transport: cristae takes place in the cristae H +, will draw in H +, creating a high concentration which can be used to proton pump drive a proton pump Electron Transport:

36. Proton Pumping: ATP synthase powers the enzyme, ATP synthase

37. Proton Pumping: ATP synthase powers the enzyme, ATP synthase …which is then used to make ATP

38. So what???? How long can you live without food? –~8 weeks if you’re healthy to start How long can you live without water? –~3-5 days if not in excessive heat or cold How long can you live without oxygen? –Minutes! ~5 minutes Why? ATP!! This is the energy your cells can use!!

39. DOING THE MATH: GlycolysisATP Glycolysis, in cytoplasm, no O 2 net 2 ATP

40. DOING THE MATH: GlycolysisATP Glycolysis, in cytoplasm, no O 2 net 2 ATP Krebs CycleATP Krebs Cycle, in matrix, with O 2 2 ATP

41. DOING THE MATH: GlycolysisATP Glycolysis, in cytoplasm, no O 2 net 2 ATP Krebs CycleATP Krebs Cycle, in matrix, with O 2 2 ATP (oxygen that is used In Electron Transport Chain allows total combustion of glucose in Krebs Cycle) Electron transport chainsATP Electron transport chains, in inner membrane with O 2 32 ATP

42. DOING THE MATH: GlycolysisATP Glycolysis, in cytoplasm, no O 2 net 2 ATP Krebs CycleATP Krebs Cycle, in matrix, with O 2 2 ATP Electron transport chainsATP Electron transport chains, in inner membrane with O 2 32 ATP ATP TOTAL: 36 ATP

43. DOING THE MATH: GlycolysisATP Glycolysis, in cytoplasm, no O 2 net 2 ATP* Krebs Cycle ATP Krebs Cycle, in matrix mitochondria, with O 2 2 ATP Electron transport chainsATP Electron transport chains, in inner membrane with O 2 32 ATP --------------- ATP TOTAL: 36 ATP Glycolysis make 4 ATP, but it takes 2 ATP for activation energy (the match that gets the fire going).

44. DOING THE MATH: GlycolysisATP Glycolysis, in cytoplasm, no O 2 2 ATP Krebs Cycle ATP Krebs Cycle, in matrix, with O 2 2 ATP Electron transport chainsATP Electron transport chains, in inner membrane with O 2 32 ATP ------------- TOTAL: ATP NET YIELD, 1 glucose: approx. 36 net ATP

45. Fermentation And if there’s not enough O 2 ? Anaerobic respiration YEAST ANIMALS BACTERIA

46. CELLULAR RESPIRATION ! C 6 H 12 O 6 + 6 O 2 6CO 2 + 6H 2 O + ATP What are the reactants? What are the products? What factors might influence the rate of cellular respiration? What could we measure? Enzymes

47. Cell respiration review Write the equation for cellular respiration from memory with the names of each molecule below. (You built all of these in the first week of school!! Remember?)

48. SEM of Mitochondria