Cellular Respiration!

1. Cellular Respiration!

2. CA State Standard CELL BIOLOGY • 1.g. Students know the role of the mitochondria in making stored chemical-bond energy available to cells by completing the breakdown of glucose to carbon dioxide.

3. How do heterotrophs get energy? They eat it!

4. When you eat food, how does it become the energy that makes your body function? Through a process called cellular respiration!

5. As this figure skater breathes, she takes in oxygen. Why? The oxygen is used in the process of cellular respiration, which allows her cells to break down glucose and turn it into ATP. This enables her to have the energy to perform her feats on ice.

6. What is Cellular Respiration? Cellular Respiration is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.

7. What is the equation for Cellular Respiration? Hint: It’s the opposite of Photosynthesis!

8. What is the equation for Cellular Respiration? Oxygen What we breathe 6O2 + C6H12O6 6H2O + 6CO2 + Energy Carbon Dioxide What we exhale Water Glucose

9. Cellular Respiration has 3 Stages 1. Glycolysis (occurs in the cytoplasm) 2. Krebs Cycle (occurs in the mitochondria) 3. Electron Transport Chain (occurs in the inner membrane of the mitochondria)

10. Overview of Cellular Respiration Glycolysis: Breakdown of Glucose Pyruvic acid Cytoplasm Krebs Cycle and Electron Transport Chain: Production of ATP

11. Pyruvic Acid Alcohol & CO2 or Lactic Acid ATP!

12. Glycolysis • Glyco = sugar; lysis = breaking; so glycolysis is the breaking of glucose! • It occurs in the cytoplasm of the cell. • Glycolysis – the process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound. 2 ATP molecules and 2 NADH molecules are created.

13. During Glycolysis, glucose is converted to pyruvic acid, producing a small amount of ATP and NADH. Cellular respiration occurs in three stages. Pyruvic Acid

14. 1. Phosphate groups from 2 ATP are transferred to a glucose molecule Glycolysis Step 1

15. 2. Six-carbon compound broken down to two 3-carbon compounds, each with a phosphate group. Glycolysis Step 2:

16. 3. Two NADH molecules are produced, one phosphate group is transferred to each 3-carbon compound. Glycolysis Step 3:

17. 4. Two 3- carbon compounds converted to pyruvic acid and 4 molecules of ATP Glycolysis Step 4:

18. Glycolysis Glycolysis has a net gain of 2 ATP. (It uses 2 ATP but produces 4 ATP)

19. A molecule of glucose is split • 2 pyruvic acids are made • 2 ATP and 2 NADH are produced What happens in the stages of glycolysis?

20. An important example of an electron acceptor that functions in glycolysis is… NAD+ NAD+ becomes NADH when it accepts an e-

21. What happens after Glycolysis….? • Only 2 ATP were made and pyruvic acid still has a lot of energy in its bonds… • If there is O2 available  AEROBIC RESPIRATION! • If there is NO O2 available  FERMENTATION (ANAEROBIC)

22. Aerobic Respiration Pyruvic Acid Aerobic = requires O2 When oxygen is present, pyruvic acid and NADH are used to make a large amount of ATP in the Mitochondrion during the Krebs Cycle and Electron Transport Chain.

23. Fermentation (Anaerobic respiration) Pyruvic Acid When oxygen is not present, pyruvic acid is converted to either lactic acid or alcohol and carbon dioxide through fermentation.

25. Two Types of Fermentation: Alcoholic Fermentation Lactic Acid Fermentation

26. Two Types of Fermentation: Alcoholic Fermentation • Pyruvic acid + NADH  alcohol + CO2 + NAD+ • WHO? Yeast and other microorganisms • Example: This is how bread and alcohol are made!

28. Two Types of Fermentation: Lactic Acid Fermentation • Pyruvic acid + NADH  lactic acid + NAD+ • WHO? Animals, prokaryotes • Examples: • Lactic acid build-up creates sore muscles after intense exercise • Cheese, yogurt, sour cream, pickles, kimchi are made this way

30. Fermentation makes cheese! Fungi or bacteria are added to milk to carry out lactic acid fermentation on some of the sugar in the milk. This is how cheese is made!

31. Lactic Acid Fermentation!

32. If OXYGEN is available…. CELLULAR RESPIRATION TAKES PLACE!

33. When oxygen is available, Pyruvic Acid goes into the mitochondrion and goes through the Krebs Cycle and Electron Transport Chain to get ATP! • Krebs Cycle occurs in area enclosed by inner membrane. • Electron Transport Chain occurs within inner membrane itself.

34. Cellular Respiration 1. Glycolysis (breakdown of glucose) 3. Electron Transport Chain 2. Krebs Cycle Production of ATP!

35. 2. KREBS CYCLE • Pyruvic acid from glycolysis enters the mitochondria and gets transformed into Acetyl-CoA and other carbon compounds. • CO2 is produced. • 8 ATP, FADH2 and NADH are created. • Occurs in the mitochondria

36. KREBS CYCLE Pyruvic Acid • When oxygen is present, pyruvic acid enters the mitochondrion and is converted to a compound called Acetyl-CoA. • CO2 is released.

37. Krebs Cycle Citric Acid 3. Acetyl-CoA is converted into Citric Acid, releasing more CO2. Acetyl-CoA

38. Citric Acid 4. More CO2 is released from the 6-carbon compound, forming a 5-carbon compound. 5. Electrons are transferred to NAD+ making NADH.

39. 6. More CO2is released when Citric Acid is converted into a 5-carbon compound. 7. ATP and NADH are made.

40. 8. Electrons are transferred to FAD making FADH2 9. The 4-carbon compound is converted back into citric acid and the cycle starts all over!

41. NADH and FADH2 go into the Electron Transport Chain, providing high-energy electrons, leading to the production of ATP!

42. Electron Transport Chain The Electron Transport Chain occurs in the inner membrane of the mitochondria. Inner membrane of mitochondria

43. Steps of theElectron Transport Chain 1. High-energy electrons from NADH and FADH2 are passed along proteins in the membrane. Inner membrane of mitochondria

44. 2. At the end of the electron transport chain, OXYGENis the final electron acceptor of the electrons. The electrons combine with hydrogen ions and form WATER!

45. The final electron acceptor in aerobic respiration is Oxygen!

46. The final end product in the electron transport chain is water

47. 3. As the high-energy electrons are passed along, their energy is used to pump hydrogen ions, H+, across the membrane. This creates a concentration gradient. Inner membrane of mitochondria

48. 4. ATP is created as H+ ions diffuse through ATP Synthase, a channel protein in the membrane. ATP Synthase

49. The complete breakdown of glucose through glycolysis and respiration results in the production of chemical energy in the form of 36 total molecules of ATP.

50. Cellular Respiration Quiz • What is cellular respiration? • What is the balanced equation for cellular respiration? • Glycolysis occurs in the mitochondrion/cytoplasm of the cell. (circle the correct response) • Glucose is broken down in glycolysis/Krebs Cycle/ electron transport chain. (circle the correct response) • CO2 is produced in glycolysis/Krebs Cycle/ electron transport chain. (circle the correct response) • The Krebs Cycle occurs in the mitochondrion/cytoplasm of the cell. (circle the correct response) • Why do we need to breathe oxygen? • After glycolysis, if there is no oxygen present, what process occurs instead of the Krebs Cycle and electron transport chain?