Cellular Respiration


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Define what is respiration
Differentiate aerobic from anaerobic respiration
Explain the 4 main stages of aerobic respiration
Explain the process of fermentation

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Cellular Respiration

  1. 1. Aim: introduce students to cellular respiration Objectives:  Define what is respiration  Differentiate aerobic from anaerobic respiration  Explain the 4 main stages of aerobic respiration  Explain the process of fermentation
  2. 2. Respiration Respiration uses chemical energy in the form of carbohydrates, lipids, or proteins, to produce ATP
  3. 3. 10What is energy muscleused for? contraction Respiration supplies the energy for germination chemical changes in cells cell division
  4. 4. What Is ATP?• ATP (Adenosone Tri-Phosphate)• ATP is the short-term energy store of the cell• ATP is used by cells to perform their daily tasks
  5. 5. How Do We Get Energy From ATP?By breaking the high- energy bonds between the last two phosphates in ATP
  6. 6. ATP + H2O --- > ADP + Pi + Energy
  7. 7. ATP ATP can be broken down into a molecule of ADP by removing one of the phosphate groups  This releases energy ADP can be remade into ATP later when the cell has food that can be broken down (i.e glucose)
  8. 8. Cell Respiration and Production of ATP The breakdown of organic molecules (carbohydrates, lipids, proteins) releases energy The energy released is used to build molecules of ATP When a cell requires some energy it will break down ATP
  9. 9. Respiration There are two types of respiration  Aerobic (requires oxygen)  Anaerobic (does not requires oxygen)
  10. 10. Mitochondria Structure Mitochondria Smooth outer Membrane Folded inner membrane Folds called Cristae Space inside cristae called the Matrix
  11. 11. Aerobic Respiration  Requires Oxygen  Main type of respiration that occurs in most situations in Plants and Animals  Involves complete breakdown of glucose back to CO2 and Water C6H12O6 + 6O2 ----- > 6CO2 + 6H2O + 38 ATPs
  12. 12. Stages of Aerobic Respiration Glycolysis Preparation for Citric Acid Cycle (link raction) The Krebs Cycle (Citric acid cycle) The Electron Transport Chain
  13. 13. Where Does Aerobic Respiration Take Place?• Glycolysis occurs in the Cytoplasm• Link reaction and Krebs Cycle on the matrix• ETC takes place in the inner membrane of the mitochondria
  14. 14. Glycolysis Glycolysis is the first stage of cellular respiration Occurs in cytoplasm Glucose (6C) is broken down into 2 molecules of 3-carbon molecule pyruvate  ATP and NADH are produced as part of the process
  15. 15. The link reaction Before the next stage can begin, pyruvate is transported inside the mitochondria. The pyruvate releases one molecule of CO2. It then combines with an enzyme called Coenzyme A to form the two-carbon molecule acetyl coenzyme A.
  16. 16. Krebs cycle Occurs in the matrix of the mitochondria Cyclical series of oxidation reactions that give off CO2 Turns twice per glucose molecule Produces two ATP
  17. 17. Electron Transport Chain Occurs in the inner membrane of the mitochondria Electrons are passed along the chain, from one protein to another Electrons drop in energy as they go down the chain and until they end up with O2. 34 ATP are produced during this stage
  18. 18. Name of stage Site Key events12.3.4.
  19. 19. Name of stage Site Key events1 Glycosis Cytoplasm2. Preparation for Matrix of thecitric acid cycle mitochondria3. Citric acid cycle Matrix of(Krebs cycle) Mitochondria4. Electron transport Innerchain membrane of mitochondria
  20. 20. Anaerobic Respiration ‘Fermentation’ Releases energy from glucose without the presence of oxygen There are 2 types of fermentation:  Alcoholic  Lactic acid ATP is still produced from glucose but not as efficiently as with Aerobic Respiration  Produces only 2 ATP
  21. 21. Alcoholic fermentationOverall Equation: Glucose→ 2 Ethanol + 2 CO2 + 2 ATP• Yeast produce wine and beer and cause bread to rise
  22. 22. 31Wine makingGrapes are crushed and the sugar they contain is fermentedby yeasts to produce alcohol and carbon dioxide.The carbon dioxide usually escapes but if the wine isbottled before fermentation is complete, the carbon dioxidedissolves and escapes as bubble when the bottle is openedThis is the case with ‘sparkling’ wines such as ChampagneDifferent varieties of grape produce different types of wine
  23. 23. 35Baking In baking, yeast is added to a mixture of flour and water, made into the form of a doughThe yeast first changes the flour starch into sugar and thenferments the sugar into alcohol and CO2The CO2 forms bubbles in the dough which cause it toexpand (‘rise’)When the dough is baked, the heat evaporates thealcohol but makes the trapped bubbles expand giving thebread a ‘light’ texture
  24. 24. 37The ‘holes’ in thebread are made bythe carbon dioxidebubbles.This gives thebread a ‘light’texture
  25. 25. Lactic Acid Fermentation Overall Equation: Glucose → 2 Acid Lactic + 2 ATP • Bacteria produce yogurt and cheese. • In Muscle Cells- During exercise, the oxygen in the muscle tissue is decreased to an extent that aerobic respiration does not occur at a sufficient rate. Hence, there is a buildup of lactic acid and your muscles get tired
  26. 26. Factors Affecting RespirationKind of Cell or Tissue  Young and Developing cells usually have higher respiration rates  Developing and Ripening Fruit and Seeds, too  Older Cells and Structural Cells Respire at Lower Rates
  27. 27. Factors Affecting RespirationTemperature  Respiration generally Has Higher Optimum and Maximum Temps than PS Rxs  Can Have Net Dry Matter Loss at High Temps where Respiration Exceeds PS  Temp Refers to Temp Inside Plant or Animal Cell, not Air Temp  Using Irrigation to Help Cool the Plant Can Keep the Plant in Net Gain Range
  28. 28. Factors Affecting Respiration Oxygen  Low O2 Can Reduce Aerobic Respiration and Increase Anaerobic Respiration
  29. 29. Factors Affecting RespirationATP Higher [ATP] Reduces Rate of Respiration  Feedback Inhibition  Usually Occurs when other Metabolic Processes Have Slowed or Stopped
  30. 30. Factors Affecting RespirationCO2  Higher CO2 Levels Reduce Rate of Respiration  Feedback Inhibition  Seldom Occurs except when O2 Levels Are Limited  Flooded, Compacted Soils