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cellular_respiration_2 Biology grade 9.ppt
- 1. Cellular Respiration Cellular Respiration HonorsBiology Honors Biology
- 2. What is CellularRespiration? What is Cellular Respiration? The process of converting food energy The process of converting food energy into ATP energy into ATP energy C C6 6H H12 12O O6 6 + 6 O + 6 O2 2 → → 6 CO 6 CO2 2 + 6 H + 6 H2 2O + 36 ATP O + 36 ATP
- 3. Why are bothPhotosynthesis and Cell Why are both Photosynthesis and Cell Respiration important to Ecosystems? Respiration important to Ecosystems? Light is the ultimate Light is the ultimate source of energy for all source of energy for all ecosystems ecosystems Chemicals cycle and Chemicals cycle and Energy flows Energy flows Photosynthesis and Photosynthesis and cellular respiration are cellular respiration are opposite reactions opposite reactions
- 4. Why do plantsneed both Why do plants need both chloroplasts and mitochondria? chloroplasts and mitochondria? Chloroplasts use Chloroplasts use energy from the energy from the sun to make sun to make glucose glucose Mitochondria Mitochondria convert glucose to convert glucose to ATP—the energy ATP—the energy currency of the cell currency of the cell
- 5. What is ATP? Whatis ATP? Adenosine Triphosphate Adenosine Triphosphate – 5-Carbon sugar (Ribose) 5-Carbon sugar (Ribose) – Nitrogenous base (Adenine) Nitrogenous base (Adenine) – 3 Phosphate groups 3 Phosphate groups Energy currency of the Energy currency of the cell cell The chemical bonds that The chemical bonds that link the phosphate groups link the phosphate groups together are high energy together are high energy bonds bonds When a phosphate group When a phosphate group is removed to form ADP is removed to form ADP and P, small packets of and P, small packets of energy are released energy are released
- 6. How is ATPused? How is ATP used? As ATP is broken down, it As ATP is broken down, it gives off usable energy to gives off usable energy to power chemical work and power chemical work and gives off some nonusable gives off some nonusable energy as heat. energy as heat. Synthesizing molecules for Synthesizing molecules for growth and reproduction growth and reproduction Transport work – active Transport work – active transport, endocytosis, and transport, endocytosis, and exocytosis exocytosis Mechanical work – muscle Mechanical work – muscle contraction, cilia and flagella contraction, cilia and flagella movement, organelle movement, organelle movement movement
- 7. Why use ATPenergy and not Why use ATP energy and not energy from glucose? energy from glucose? Breaking down glucose yields too much energy Breaking down glucose yields too much energy for cellular reactions and most of the energy for cellular reactions and most of the energy would be wasted as heat. would be wasted as heat. 1 Glucose = 686 kcal 1 Glucose = 686 kcal 1 ATP = 7.3 kcal 1 ATP = 7.3 kcal 1 Glucose 1 Glucose → → 36 ATP 36 ATP How efficient are cells at converting glucose into How efficient are cells at converting glucose into ATP? ATP? – 38% of the energy from glucose yields ATP, 38% of the energy from glucose yields ATP, therefore 62% wasted as heat. therefore 62% wasted as heat.
- 8. Cellular Respiration isa Redox Reaction Cellular Respiration is a Redox Reaction C C6 6H H12 12O O6 6 + 6 O + 6 O2 2 → 6 CO → 6 CO2 2 + 6 H + 6 H2 2O O Oxidation Oxidation is the loss of electrons or H is the loss of electrons or H+ + Reduction Reduction is the gain of electrons or H is the gain of electrons or H+ + Glucose is oxidized when electrons and H Glucose is oxidized when electrons and H+ + are passed are passed to coenzymes NAD to coenzymes NAD+ + and FAD before reducing or and FAD before reducing or passing them to oxygen. passing them to oxygen. Glucose is oxidized by a Glucose is oxidized by a series of smaller steps series of smaller steps so that so that smaller packets of energy are released to make ATP, smaller packets of energy are released to make ATP, rather than one large explosion of energy. rather than one large explosion of energy. (Oxidation) (Reduction)
- 9. Cell Respiration canbe divided into 4 Parts: Cell Respiration can be divided into 4 Parts: 1) Glycolysis 1) Glycolysis 2) Oxidation of Pyruvate / Transition Reaction 2) Oxidation of Pyruvate / Transition Reaction 3) The Krebs Cycle 3) The Krebs Cycle 4) The Electron Transport Chain and 4) The Electron Transport Chain and Chemiosmotic Phosphorylation Chemiosmotic Phosphorylation
- 10. Where do the4 parts of Cellular Where do the 4 parts of Cellular Respiration take place? Respiration take place? Glycolysis: Glycolysis: – Cytosol Cytosol Oxidation of Oxidation of Pyruvate: Pyruvate: – Matrix Matrix The Krebs Cycled: The Krebs Cycled: – Matrix Matrix Electron Transport Electron Transport Chain and Chain and Cheimiosmotic Cheimiosmotic Phosphorylation: Phosphorylation: – Cristae Cristae
- 11. Parts of theMitochondria Parts of the Mitochondria
- 12. Anaerobic Respiration (nooxygen required, cytoplasm) Anaerobic Respiration (no oxygen required, cytoplasm) 1. Glycolysis (substrate level) Glucose 2 Pyruvate 2 ATP 4 ATP (Net 2 ATP) 2 NADH Aerobic Respiration (oxygen required, mitochondria) Aerobic Respiration (oxygen required, mitochondria) 2. Oxidation of Pyruvate 2 Pyruvate 2 CO2 2 NADH 2 Acetyl CoA 3. Krebs Cycle (substrate level) 2 Acetyl CoA 4 CO2 2 ATP 6 NADH 2 FADH2 4. Electron Transport Chain (chemiosmotic) 10 NADH 32 ATP 2 FADH2 H2O Oxygen Total: 36 ATP produced
- 13. ATP is madein two ways: ATP is made in two ways: 1) 1) Substrate Level Substrate Level Phosphorylation Phosphorylation (glycolysis (glycolysis & Krebs cycle) & Krebs cycle) 2) 2) Chemiosmotic Chemiosmotic Phosphorylation Phosphorylation (electron (electron transport chain) transport chain) Substrate-Level Substrate-Level Phosphorylation: Phosphorylation: Energy and phosphate are Energy and phosphate are transferred to ADP using an transferred to ADP using an enzyme, to form ATP. enzyme, to form ATP. Phosphate comes from one Phosphate comes from one of the intermediate of the intermediate molecules produced from molecules produced from the breakdown of glucose. the breakdown of glucose.
- 14. Glycolysis Glycolysis Glucose (C Glucose (C6 6)is split to make ) is split to make 2 Pyruvates (C 2 Pyruvates (C3 3) ) – 1 1st st : ATP energy used to phosphorylate : ATP energy used to phosphorylate glucose (stored energy) glucose (stored energy) – 2 2nd nd : phosphorylated glucose broken : phosphorylated glucose broken down into two C down into two C3 3 sugar phosphates sugar phosphates – 3 3rd rd : the sugar phosphates are oxidized : the sugar phosphates are oxidized to yield electrons and H to yield electrons and H+ + ions which are ions which are donated to 2 NAD donated to 2 NAD+ + → → 2 NADH (stored 2 NADH (stored electron and hydrogen for the Electron electron and hydrogen for the Electron Transport Chain) Transport Chain) – 4 4th th : The energy from oxidation is used : The energy from oxidation is used to make 4 ATP molecules (net 2 ATP) to make 4 ATP molecules (net 2 ATP) This is substrate level phosphorylation This is substrate level phosphorylation because an enzyme transfers because an enzyme transfers phosphate to ADP making ATP phosphate to ADP making ATP Glycolysis produces very little ATP Glycolysis produces very little ATP energy, most energy is still stored in energy, most energy is still stored in Pyruvate molecules. Pyruvate molecules. Glucose 2 Pyruvate 2 ATP 4 ATP (Net 2 ATP) 2 NADH
- 15. Oxidation of Pyruvate/Transition Reaction Oxidation of Pyruvate /Transition Reaction When Oxygen is present, 2 Pyruvates go to the matrix where they are converted into 2 Acetyl CoA (C2). Multienzyme complex: – 1st: each Pyruvate releases CO2 to form Acetate. – 2nd: Acetate is oxidized and gives electrons and H+ ions to 2 NAD+ → 2 NADH. – 3rd Acetate is combined with Coenzyme A to produce 2 Acetyl CoA molecules. 2 NADH’s carry electrons and hydrogens to the Electron Transport Chain. 2 Pyruvate 2 CO2 2 NADH 2 Acetyl CoA
- 16. The Krebs Cycle/ Citric Acid Cycle The Krebs Cycle / Citric Acid Cycle 8 Enzymatic Steps in Matrix of Mitochondria: Break down and Oxidize each Acetyl CoA (2-C’s) to release 2 CO2 and yield electrons and H+ ions to 3 NAD+ + 1 FAD → 3 NADH + FADH2. This yields energy to produce ATP by substrate level phosphorylation. The first step of the Krebs cycle combines Oxaloacetate (4 C’s) with Acetyl CoA to form Citric Acid, then the remaining 7 steps ultimately recycle oxalacetate. Two Turns of the Krebs Cycle are required to break down both Acetyl Coenzyme A molecules. The Krebs cycle produces some chemical energy in the form of ATP but most of the chemical energy is in the form of NADH and FADH2 which then go on to the Electron Transport Chain. 2 Acetyl CoA 4 CO2 2 ATP 6 NADH 2 FADH2
- 17. The Electron TransportChain The Electron Transport Chain NADH and FADH NADH and FADH2 2 produced produced earlier, go to the Electron earlier, go to the Electron Transport Chain. Transport Chain. NADH and FADH NADH and FADH2 2 release release electrons to carriers/proteins electrons to carriers/proteins embedded in the membrane embedded in the membrane of the cristae. As the of the cristae. As the electrons are transferred, H electrons are transferred, H+ + ions are pumped from the ions are pumped from the matrix to the intermembrane matrix to the intermembrane space up the concentration space up the concentration gradient. Electrons are gradient. Electrons are passed along a series of 9 passed along a series of 9 carriers until they are carriers until they are ultimately donated to an ultimately donated to an Oxygen molecule. Oxygen molecule. ½ O ½ O2 2 + 2 electrons + 2 H + 2 electrons + 2 H+ + (from NADH and FADH (from NADH and FADH2 2) ) → → H H2 2O. O. 10 NADH 32 ATP 2 FADH2 H2O Oxygen http://vcell.ndsu.nodak.edu/animations/etc/movie.htm
- 18. Chemiosmotic Phosphorylation Chemiosmotic Phosphorylation Hydrogenions travel down their concentration gradient through a channel Hydrogen ions travel down their concentration gradient through a channel protein coupled with an enzyme called protein coupled with an enzyme called ATP Synthase ATP Synthase. . As H As H+ + ions move into the matrix, energy is released and used to combine ions move into the matrix, energy is released and used to combine ADP + P ADP + P → → ATP. ATP. Hydrogens are recycled and pumped back across the cristae using the Hydrogens are recycled and pumped back across the cristae using the Electron Transport Chain. Electron Transport Chain. ATP diffuses out of the mitochondria through channel proteins to be used ATP diffuses out of the mitochondria through channel proteins to be used by the cell. by the cell. http://vcell.ndsu.nodak.edu/animations/atpgradient/movie.htm
- 19. ATP Synthase ATP Synthase Multisubunitcomplex Multisubunit complex with 4 parts: with 4 parts: – Rotor Rotor – spins as H – spins as H+ + ions flow ions flow – Stator Stator – holds the rotor and – holds the rotor and knob complex together in the knob complex together in the cristae cristae – Internal Rod Internal Rod – extends – extends between rotor and knob, spins between rotor and knob, spins when rotor spins which then when rotor spins which then turns the knob turns the knob – Knob Knob – contains 3 catalytic – contains 3 catalytic sites that when turned change sites that when turned change shape and activate the enzyme shape and activate the enzyme used to make ATP used to make ATP
- 20. Review ATP Production: ReviewATP Production: 1) Glycolysis 1) Glycolysis → → 2 ATP 2 ATP 2) Oxidation of Pyruvate 2) Oxidation of Pyruvate → → No ATP No ATP 3) The Krebs Cycle 3) The Krebs Cycle → → 2 ATP 2 ATP 4) The Electron Transport Chain and 4) The Electron Transport Chain and Chemiosmotic Phosphorylation: Chemiosmotic Phosphorylation: – Each NADH produces 2-3 ATP so 10 Each NADH produces 2-3 ATP so 10 NADH NADH → → 28 ATP 28 ATP – Each FADH Each FADH2 2 produces 2 ATP so 2 produces 2 ATP so 2 FADH FADH2 2 → → 4 ATP 4 ATP Total = 36 ATP Total = 36 ATP 1 Glucose = 686 kcal 1 Glucose = 686 kcal 1 ATP = 7.3 kcal 1 ATP = 7.3 kcal 1 Glucose 1 Glucose → → 36 ATP 36 ATP How efficient are cells at converting How efficient are cells at converting glucose into ATP? glucose into ATP? – 38% of the energy from glucose 38% of the energy from glucose yields ATP, therefore 62% wasted as yields ATP, therefore 62% wasted as heat (used to maintain body heat (used to maintain body temperature or is dissipated) temperature or is dissipated) – Ex. Most efficient Cars: only 25% of Ex. Most efficient Cars: only 25% of the energy from gasoline is used to the energy from gasoline is used to move the car, 75% heat. move the car, 75% heat.
- 21. All Types ofMolecules can be used All Types of Molecules can be used to form ATP by Cell Respiration: to form ATP by Cell Respiration: Proteins, Carbohydrates, Proteins, Carbohydrates, and Lipids must first be and Lipids must first be broken down into their broken down into their monomers and absorbed monomers and absorbed in the small intestine. in the small intestine. Monomers may be Monomers may be further broken down into further broken down into intermediate molecules intermediate molecules before entering different before entering different parts of Cell respiration parts of Cell respiration to ultimately form ATP. to ultimately form ATP.
- 22. Anaerobic Respiration: Fermentation AnaerobicRespiration: Fermentation If there is NO oxygen, then cells can make ATP by If there is NO oxygen, then cells can make ATP by Fermentation Fermentation Without oxygen, Oxidation of Pyruvate and the Electron Without oxygen, Oxidation of Pyruvate and the Electron Transport Chain do not operate. Transport Chain do not operate. Glucose Glucose → → Pyruvate Pyruvate → → Lactate Lactate NAD NAD+ + Glycolysis Glycolysis 2 NADH 2 NADH Reduction Rxn Reduction Rxn or or 2 ATP 2 ATP Alcohol + CO Alcohol + CO2 2 Fermentation yields a net gain of 2 ATP by substrate level phosphorylation Fermentation yields a net gain of 2 ATP by substrate level phosphorylation for every 1 Glucose. (Inefficient) for every 1 Glucose. (Inefficient) Two Forms of Fermentation Two Forms of Fermentation: : Lactic Acid Fermentation (animals) Lactic Acid Fermentation (animals) Alcohol Fermentation (yeast) Alcohol Fermentation (yeast)