Living Organisms & Energy

1. Living Organisms & Energy Moretz, biology 2017

2. Lecture Outline • Importance of energy in living organisms • Photosynthesis • Process of photosynthesis • Purpose of photosynthesis • Respiration • Purpose of respiration • Process of respiration • Fermentation

3. Importance of Energy • Living organisms need energy to do everything. • Move • Grow • Reproduce • Photosynthesis & respiration are needed for living organisms to get energy.

4. Photosynthesis vs. Respiration • Photosynthesis- turns energy into sugars • Respiration- turns sugars into energy Photosynthesis Energy Sugars Respiration

5. How do plants meet their energy needs? • Remember, science is a process….. …..a brief history lesson is in order

6. The process of understanding photosynthesis • Until almost 350 years ago, plants were thought to feed on soil • Jan Baptista van Helmont • Planted willow tree in pot • Allowed tree to grow for 5 years • Compared weight of tree and soil to original weight • Tree gained 74kg, soil lost 57g

7. The process of understanding photosynthesis • 100 yrs later we learned that plants release oxygen into the atmosphere • Joseph Priestly • Candles “damaged” air • Sprigs of mint “restored” air

8. The process of understanding photosynthesis • Finally, ~1800 Jan Ingenhousz determined: • Air was “restored” only in the presence of sunlight • Only by a plant’s green leaves, not by it roots • But, he suggested that the source of the oxygen was CO2

9. What is photosynthesis? • photo = light • synthesis = to put together

10. Process of photosynthesis • Process by which a cell captures energy and uses it to make food. • Photosynthesis is a 2 step process: • Capture energy • Turn energy into food

11. Step 1: Capturing Energy • Plants capture the light energy from the sun. • Chlorophyll absorbs the light energy. • Pigment that is good at absorbing a certain wavelength of light. • Located in the chloroplast. • Organelle located ONLY in plant cells. • The light energy captured by the chlorophyll is needed to turn energy into food.

12. Capturing Energy

13. Capturing Energy

14. Capturing Energy Chlorophyll

15. Step 2: Turning energy into food • Plant cells use the captured light energy to produce “food.” • Water (H2 O) and carbon dioxide (CO2 ) are needed to make the food. • Roots absorb water from the soil. • Carbon dioxide enters the plant through stomata. • Light energy changes the water & carbon dioxide into glucose and oxygen (O2).

16. Stomata • Small openings on the underside of leaves. • Gases enter and exit through these openings.

17. Stomata • Small openings on the underside of leaves. • Gases enter and exit through these openings.

18. Glucose • Glucose = C6H12O6 • “Food” produced during photosynthesis. • Simple carbohydrate (sugar)

19. Process of photosynthesis • 6 CO2 + 6H2 O C6H12O6 + 6O2 • 6 carbon dioxide molecules and 6 water molecules produces 1 glucose molecule and 6 oxygen molecules. light

20. Photosynthetic Organisms • Carried out by a variety of organisms • simple bacteria, to algae and complex plants. • Photosynthetic organisms = “producer” or “autotroph.”

24. Importance of Photosynthesis • Releases oxygen into the atmosphere. • Dead plant matter is a source of fossil fuels. • Most living things obtain energy either directly or indirectly from the sun’s energy captured during photosynthesis.

25. Importance of Photosynthesis • Without photosynthesis, living organisms would not get energy!!! • Energy enters the ecosystem through photosynthesis. • Plants use the sun’s energy to make glucose. • All other organisms consume glucose from the producers as a source of energy.

26. Flow of Energy

27. Flow of Energy

28. Before respiration… • All organisms get energy from the food they eat / make.

29. Before respiration… • Food passes through the digestive system and is broken into smaller pieces.

30. Before respiration… • Smaller food molecules pass from the digestive system to the blood stream. • Small sugar molecules (GLUCOSE) then go to the cells where respiration occurs.

31. Respiration • What? • Process of getting energy. • Cells break down sugar (glucose) and release the energy. • Who? • ALL living organisms • Where? • Occurs in the cytoplasm and mitochondria of all cells, in BOTH plant and animal cells.

32. The Process of Respiration • Glycolysis (fermentation) • Glucose is broken into smaller molecules (pyruvate). • Occurs in the cytoplasm. • Anaerobic - Oxygen is NOT needed. • Four molecules of energy (ATP) is produced. • Two molecules are used in the process. • Net production = 2 molecules of ATP

33. The Process of Respiration Glycolysis • Glucose is broken into smaller molecules (pyruvate). • Two molecules of energy (ATP) is released.

34. The Process of Respiration Glycolysis • Glucose is broken into smaller molecules (pyruvate). • Two molecules of energy (ATP) is released.

35. The Process of Respiration • The Kreb’s Cycle • Pyruvate goes into the mitochondria. • Pyruvate molecules is broken into even smaller molecules. • Pyruvate turns into Acetyl-CoA

36. The Process of Respiration • The Kreb’s Cycle • Pyruvate goes into the matrix of the mitochondria.

37. The Process of Respiration • The Kreb’s Cycle • Pyruvate goes into the matrix of the mitochondria. • Pyruvate molecules is broken into even smaller molecules. • Pyruvate turns into Acetyl-CoA • Acetyl-CoA is turned into ATP • CO2 is produced. • Electron carrying molecules are produced (FADH and NADH) • Aerobic - Oxygen is required. • 1molecules of energy (ATP) is produced.

38. The Process of Respiration • The Kreb’s Cycle • Pyruvate goes into the mitochondria. • Pyruvate molecules is broken into even smaller molecules. • Pyruvate turns into Acetyl-CoA • Acetyl-CoA is turned into ATP • FADH and NADH are produced. • CO2 is produced. • 2 molecules of energy (ATP) is produced.

39. The Process of Respiration 3. Electron Transport Chain • Electrons are passed from one molecule to another. • Given from the NADH and FADH molecules • In the membrane of the mitochondria

40. The Process of Respiration

41. The Process of Respiration 3. Electron Transport Chain • Electrons are passed from one molecule to another. • Given from the NADH and FADH molecules • In the membrane of the mitochondria • Produces ATP • Oxygen is the last electron acceptor. • Joins with H+ and produces water. • Aerobic - Oxygen is required. • 32 molecules of energy (ATP) is produced.

42. The Process of Respiration

43. The Process of Respiration Glucose In the cytoplasm Small molecules In the mitochondria Energy

44. The Process of Respiration Water Oxygen Carbon dioxide Smaller molecules LOTS of Energy

45. Process of respiration C6H12O6 + 6O2 6CO2 + 6H2 O + ATP • One molecule of glucose and six molecules of oxygen make six molecules of carbon dioxide, six water molecules, and 36 molecules of ATP.

46. ATP = Energy • Universal energy storage molecule. • All organisms break down ATP to get energy. • Energy is released when the chemical bonds in ATP are broken.

47. Fermentation • What happens if oxygen is not available? • The cell can use Fermentation instead!! • Occurs in the Cytoplasm • Just like glycolysis!! • Anaerobic respiration process

48. 2 Types of Fermentation • Alcoholic Fermentation • Yeasts use this process to form ethyl alcohol and carbon dioxide as waste products. • This causes bread dough to rise • This is how some alcoholic beverages are made Pyruvic Acid + NADH  alcohol + CO2 + NAD+

49. Anaerobic respiration • Alcoholic fermentation

50. Lactic Acid Fermentation • Occurs in bacteria (unicellular organisms) • This is how cheese, yogurt, and pickles are made. • Occurs in muscles during rapid exercise • When your body runs out of oxygen your muscle cells must produce some ATP using fermentation and glycolysis • Lactic Acid build-up causes muscle soreness or burning after intense activity. Pyruvic Acid + NADH  lactic acid + NAD+