Cellular Respiration - Chapter 9 PDF

Chapter 9 - Cellular Respiration I. Introduction II. Glycolysis III. Citric acid cycle IV. Oxidative phosphorylation V. Fermentation and Anaerobic respiration VI. Branching out from glucose VII. Control of cellular respiration  Release E for work...

Chapter 9 - Cellular Respiration I. Introduction II. Glycolysis III. Citric acid cycle IV. Oxidative phosphorylation V. Fermentation and Anaerobic respiration VI. Branching out from glucose VII. Control of cellular respiration  Release E for work Heat and entropy produced Catabolic Reactions Complex molecule -------------------- Simple molecule (stored PE) ATP E for work Heat and entropy produced organic molecules + Oxygen -------------------- Carbon Dioxide and Water (sugar) I. Introduction Light energy ECOSYSTEM Photosynthesis in chloroplasts Organic CO2 + H2O molecules+ O2 Cellular respiration in mitochondria ATP ATP powers most cellular work Heat energy Cellular Respiration types Aerobic – Oxygen is consumed as a reactant along with the organic fuel (sugar) Most common respiration, the term cellular respiration sometimes just refers to aerobic respiration Cellular Respiration Types Fermentation – Partial degradation of sugars that occurs without the use of oxygen anaerobic How do catabolic reactions make E (ATP)? Transfer of e- during chemical reactions, releases E from organic molecules and E is used to make ATP REDOX reactions – e- transfer from one molecule to another Oxidation- loss of e- Reduction- gain of e- Na + Cl Na+ + Cl- Oxidation/Reduction Reaction GER = electron acceptor, oxidizing agent, substance is reduced (RIG) An electron acceptor is a chemical entity that accepts electrons transferred to it from another compound. It is an oxidizing agent that, by virtue of its accepting electrons, is itself reduced in the process. An electron donor is a chemical entity that donates electrons to another compound. It is a reducing agent that, by virtue of its donating electrons, is itself oxidized in the process. LEO = electron donor, reducing agent, substance is oxidized (OIL)  Figure Reactants Products LEO becomes oxidized Energy becomes reduced GER Methane Oxygen Carbon dioxide Water (reducing (oxidizing agent) agent) If complete loss/gain of e- occurs, ionic bond, if not complete, covalent © 2017 Pearson Education, Inc.  Figure LEO = electron donor, reducing agent, substance is oxidized becomes oxidized becomes reduced GER GER = electron acceptor, oxidizing agent, substance is reduced © 2017 Pearson Education, Inc. In general If a carbon-containing molecule gains H atoms or loses O atoms during a reaction, it’s likely been reduced (gained electrons, GER/RIG) If a carbon-containing molecule loses H atoms or gains O atoms, it’s probably been oxidized (lost electrons, LEO/OIL) Oxidation/Reduction In glucose, carbon is associated with H atoms, while in carbon dioxide, it is not associated with any H. So, we would predict that glucose is oxidized in this reaction. Similarly, the O atoms in O2, end up being associated with more H after the reaction than before, so we would predict that oxygen is reduced.  Figure 9.4 NAD+ NADH Dehydrogenase 2[H] Oxidation of NADH Nicotinamide (from food) Nicotinamide (oxidized form) (reduced form) Reduction of NAD+ Carbon gains H, therefore it is being reduced © 2017 Pearson Education, Inc. 3 Stages of Cellular Respiration 1. Glycolysis – Breakdown 1 glucose to 2 pyruvate in cytosol Makes NADH and ATP 2. Citric Acid Cycle – Oxidizes pyruvate derivative to CO2 and completes glucose degradation in mitochondrial matrix Makes NADH and ATP 3. Oxidative Phosphorylation 3 Stages of Cellular Respiration 3. Oxidative Phosphorlyation. Electron Transport Chain and Chemiosmosis – 3a. ETC e- from glycolysis and citric acid cycle, mostly carried by NADH are passed molecule to molecule while e- combines with Oxygen and H+ to make water 3 Stages of Cellular Respiration 3. Oxidative Phosphorlyation. Electron Transport Chain and Chemiosmosis – 3b. Chemiosmosis – ATP synthesis powered by the redox reactions of ETC that have released E to drive endergonic synthesis of ATP, through the H+ gradient across the inner mitochondria membrane I. Introduction Electrons via NADH GLYCOLYSIS Glucose Pyruvate CYTOSOL MITOCHONDRION ATP Substrate-level  Electrons Electrons via NADH via NADH and FADH2 GLYCOLYSIS PYRUVATE OXIDATION CITRIC ACID Glucose Pyruvate Acetyl CoA CYCLE CYTOSOL MITOCHONDRION ATP ATP Substrate-level Substrate-level I. Introduction Electrons Electrons via NADH via NADH and FADH2 GLYCOLYSIS PYRUVATE OXIDATIVE OXIDATION CITRIC PHOSPHORYLATION ACID Glucose Pyruvate Acetyl CoA CYCLE (Electron transport and chemiosmosis) CYTOSOL MITOCHONDRION ATP ATP ATP Substrate-level Substrate-level Oxidative II. Glycolysis Harvest chemical energy by oxidizing glucose to pyruvate Glycolysis (“splitting of sugar”) breaks down glucose into two molecules of pyruvate Glycolysis occurs in the cytoplasm and has two major phases: – Energy investment phase – Energy payoff phase Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings II. Glycolysis CITRIC OXIDATIVE PYRUVATE GLYCOLYSIS ACID PHOSPHORYL- OXIDATION CYCLE ATION ATP II. Glycolysis Energy investment phase Glucose 2 ADP + 2 P 2 ATP used Energy payoff phase 4 ADP + 4 P 4 ATP formed 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+ 2 Pyruvate + 2 H2O Net Glucose 2 Pyruvate + 2 H2O 4 ATP formed – 2 ATP used 2 ATP 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+ II. Glycolysis Glucose ATP Hexokinase ADP Glucose Glucose-6-phosphate ATP Hexokinase ADP Glucose-6-phosphate II. Glycolysis Glucose ATP 1 Hexokinase ADP Glucose-6- Glucose-6-phosphate 2 Phosphoglucoisomerase phosphate 2 Fructose-6-phosphate Phosphogluco- isomerase Fructose-6-phosphate II. Glycolysis Glucose ATP 1 Hexokinase ADP Fructose-6-phosphate Glucose-6-phosphate 2 *** Key regulatory step- Phosphoglucoisomerase ATP ATP allosterically regulates this enzyme 3 Fructose-6-phosphate Phosphofructo- ATP kinase 3 Phosphofructokinase ADP ADP Fructose- 1, 6-bisphosphate Fructose- 1, 6-bisphosphate  II. Glycolysis Glucose ATP 1 Hexokinase ADP Glucose-6-phosphate 2 Phosphoglucoisomerase Fructose- 1, 6-bisphosphate 4 Aldolase Fructose-6-phosphate ATP 3 Phosphofructokinase ADP 5 Isomerase Fructose- 1, 6-bisphosphate 4 Aldolase 5 Isomerase Dihydroxyacetone Glyceraldehyde- phosphate 3-phosphate Dihydroxyacetone Glyceraldehyde- phosphate 3-phosphate  2 NAD+ 6 Triose phosphate dehydrogenase 2 NADH 2 Pi + 2 H+ 2 1, 3-Bisphosphoglycerate Glyceraldehyde- 3-phosphate II. Glycolysis 2 NAD+ 6 Triose phosphate dehydrogenase 2 NADH 2 Pi + 2 H+ 2 1, 3-Bisphosphoglycerate  2 NAD+ 6 Triose phosphate II. Glycolysis dehydrogenase 2 NADH 2 Pi + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 1, 3-Bisphosphoglycerate 2 ADP 2 3-Phosphoglycerate 7 Phosphoglycero- 2 ATP kinase 2 3-Phosphoglycerate  2 NAD+ 6 Triose II. Glycolysis phosphate dehydrogenase 2 Pi 2 NADH + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 2 3-Phosphoglycerate 3-Phosphoglycerate 8 Phosphoglyceromutase 8 Phosphoglycero- 2 2-Phosphoglycerate mutase 2 2-Phosphoglycerate  2 NAD+ 6 Triose II. Glycolysis phosphate dehydrogenase 2 Pi 2 NADH + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 3-Phosphoglycerate 2 2-Phosphoglycerate 8 Phosphoglyceromutase 9 Enolase 2 2-Phosphoglycerate 2 H2O 9 Enolase 2 H2O 2 Phosphoenolpyruvate 2 Phosphoenolpyruvate  2 NAD+ 6 Triose II. Glycolysis phosphate dehydrogenase 2 P 2 NADH i + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 Phosphoenolpyruvate 2 ADP 2 3-Phosphoglycerate 8 Phosphoglyceromutase 10 Pyruvate 2 ATP kinase 2 2-Phosphoglycerate 9 Enolase 2 H2O 2 Phosphoenolpyruvate 2 ADP 10 Pyruvate kinase 2 ATP 2 Pyruvate 2 Pyruvate II. Glycolysis Energy investment phase Glucose 2 ADP + 2 P 2 ATP used Energy payoff phase 4 ADP + 4 P 4 ATP formed 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+ 2 Pyruvate + 2 H2O Net Glucose 2 Pyruvate + 2 H2O 4 ATP formed – 2 ATP used 2 ATP 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+ III. Citric Acid Cycle Complete the energy-yielding oxidation of organic molecules In the presence of O2, pyruvate enters the mitochondrion For each pyruvate the net yield is 3CO2, 4NADH + 4H+, ATP, FADH2 Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings III. Citric Acid Cycle CITRIC OXIDATIVE PYRUVATE GLYCOLYSIS ACID PHOSPHORYL- OXIDATION CYCLE ATION III. Citric Acid Cycle CYTOSOL MITOCHONDRION NAD+ NADH + H+ 2 1 3 Acetyl CoA Pyruvate CO2 Coenzyme A Transport protein III. Citric Acid Cycle CITRIC OXIDATIVE PYRUVATE GLYCOLYSIS ACID PHOSPHORYL- OXIDATION CYCLE ATION ATP  Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA III. Citric Acid Cycle Citric acid cycle 2 CO2 FADH2 3 NAD+ FAD 3 NADH + 3 H+ ADP + P i ATP Fig. 9-12-1 Acetyl CoA CoA—SH 1 Oxaloacetate Citrate Citric acid cycle Fig. 9-12-2 Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate Citric acid cycle Fig. 9-12-3 Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric NADH 3 acid + H+ cycle CO2 -Keto- glutarate Fig. 9-12-4 Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric 3 NADH acid + H+ cycle CO2 CoA— SH -Keto- glutarate 4 CO2 NAD+ NADH Succinyl + H+ CoA Fig. 9-12-5 Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric NADH 3 acid + H+ cycle CO2 CoA— SH -Keto- glutarate 4 CoA—SH 5 CO2 NAD+ Succinate Pi NADH GTP GDP Succinyl + H+ CoA ADP ATP Fig. 9-12-6 Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric NADH 3 acid + H+ cycle CO2 Fumarate CoA— SH -Keto- glutarate 6 4 CoA—SH FADH2 5 CO2 NAD+ FAD Succinate Pi NADH GTP GDP Succinyl + H+ CoA ADP ATP Fig. 9-12-7 Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Malate Citrate Isocitrate NAD+ Citric 3 NADH 7 acid + H+ H2O cycle CO2 Fumarate CoA— SH -Keto- glutarate 6 4 CoA—SH FADH2 5 CO2 NAD+ FAD Succinate Pi NADH GTP GDP Succinyl + H+ CoA ADP ATP Fig. 9-12-8 Acetyl CoA CoA—SH NADH +H+ 1 H2O NAD+ 8 Oxaloacetate 2 Malate Citrate Isocitrate NAD+ Citric 3 NADH 7 acid + H+ H2O cycle CO2 Fumarate CoA— SH -Keto- glutarate 6 4 CoA—SH FADH2 5 CO2 NAD+ FAD Succinate Pi NADH GTP GDP Succinyl + H+ CoA ADP ATP Fig. 9-11 Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA Citric acid cycle 2 CO2 FADH2 3 NAD+ FAD 3 NADH + 3 H+ ADP + P i ATP Citric Acid Cycle Wrap Up Pyruvate  Acetyl CoA  2 CO2 +NAD+ NAD+ 3 NADH 3H+ CoA ADP + Pi ATP FAD FADH2 Net yield 3CO2 4NADH 4H+ ATP IV. Oxidative phosphorylation - overview Following glycolysis and the citric acid cycle, NADH and FADH2 account for most of the energy extracted from food These two electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via oxidative phosphorylation Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Oxidative phosphorylation - overview CITRIC OXIDATIVE PYRUVATE GLYCOLYSIS ACID PHOSPHORYL- OXIDATION CYCLE ATION ATP IV. Oxidative phosphorylation A. Electron Transport Chain 50 NADH 2 e– NAD+ FADH2 2 e– FAD Multiprotein 40  FAD complexes FMN Fe S  Free energy (G) relative to O2 (kcal/mol) Fe S Q  Cyt b Fe S 30 Cyt c1 IV Cyt c Cyt a Cyt a3 20 10 2 e– (from NADH or FADH2) 0 2 H+ + 1/2 O2 H2O IV. Oxidative phosphorylation B. Chemiosmosis Electron transfer in the electron transport chain causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space H+ then moves back across the membrane, passing through channels in ATP synthase ATP synthase uses the exergonic flow of H+ to drive phosphorylation of ATP This is an example of chemiosmosis, the use of energy in a H+ gradient to drive cellular work Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Oxidative phosphorylation H+ H + H+ H+ Protein Cyt c complex of electron carriers V Q   ATP  synthase 2 H+ + 1/2O2 H2O FADH2 FAD NADH NAD+ ADP + P i ATP (carrying electrons from food) H+ 1 Electron transport chain 2 Chemiosmosis Oxidative phosphorylation IV. Oxidative phosphorylation INTERMEMBRANE SPACE B. Chemiosmosis – ATP synthase H+ Stator Rotor Internal rod Cata- lytic knob ADP + P ATP i MITOCHONDRIAL MATRIX  Electron shuttles span membrane CYTOSOL MITOCHONDRION 2 NADH or 2 FADH2 2 NADH 2 NADH 6 NADH 2 FADH2 GLYCOLYSIS PYRUVATE OXIDATIVE CITRIC OXIDATION PHOSPHORYLATION Glucose 2 ACID 2 Acetyl CoA (Electron transport Pyruvate CYCLE and chemiosmosis) + 2 ATP + 2 ATP + about 26 or 28 ATP Maximum per glucose: About 30 or 32 ATP http://www.biotechniques.com/news/3-D-mitochondria-blockbuster-captivates-students/biotechniques-306309.html  Electron shuttles span membrane 2 NADH or 2 FADH2 2 NADH GLYCOLYSIS Glucose 2 Pyruvate + 2 ATP  2 NADH 6 NADH 2 FADH2 PYRUVATE CITRIC OXIDATION ACID 2 Acetyl CoA CYCLE + 2 ATP 2 NADH or 2 FADH2 2 NADH 6 NADH 2 FADH2 OXIDATIVE PHOSPHORYLATION (Electron transport and chemiosmosis) + about 26 or 28 ATP Maximum per glucose: About 30 or 32 ATP V. Fermentation and Anaerobic Respiration During aerobic respiration, Oxygen is used to pull e- down ETC Fermentation = no ETC, uses phosphorylation to generate ATP – Anaerobe = organism that doesn’t used Oxygen as the final ETC acceptor – Ex. SO42- – Must convert NADH into NAD- V. Fermentation and Anaerobic respiration A. Alcohol fermentation 2 ADP + 2 P i 2 ATP Glucose GLYCOLYSIS 2 Pyruvate 2 NAD+ 2 NADH 2 CO2 + 2 H+ NAD+ REGENERATION 2 Ethanol 2 Acetaldehyde © 2017 Pearson Education, Inc. V. Fermentation and Anaerobic respiration B. Lactic acid fermentation 2 ADP + 2 P i 2 ATP Glucose GLYCOLYSIS 2 NAD+ 2 NADH + 2 H+ 2 Pyruvate NAD+ REGENERATION 2 Lactate  Animation: Fermentation Overview © 2017 Pearson Education, Inc. Fig. 9-19 Glucose Glycolysis CYTOSOL Pyruvate No O2 present: O2 present: Fermentation Aerobic cellular respiration MITOCHONDRION Ethanol Acetyl CoA or lactate Citric acid cycle VI. Branching out from glucose – Protein s Carbohydrates Fats catabolism of other molecules Amino Sugars Glycerol Fatty Many organic molecules can be acids acids used by cellular respiration carbohydrates Glycolysis Proteins Glucose Fats Glyceraldehyde-3- P 1g of fat produces more than 2x NH3 Pyruvate ATP as 1g of carbohydrate Acetyl CoA Thus difficult to lose weight because it takes more to burn the # Citric of calories in fat acid cycle Oxidative phosphorylation  Glucose VII. Control of cellular respiration AMP Most common mechanism is Glycolysis Fructose-6-phosphate Stimulates Feedback inhibition + Phosphofructokinase – – Decrease in ATP Fructose-1,6-bisphosphate respiration speeds up Inhibits Inhibits Increase in ATP respiration slows down Pyruvate Control catabolism base mainly on regulating the activity of ATP Citrate Acetyl CoA enzymes in the pathway Phosphofructokinase (step 3 of Citric glycolysis) acid cycle too much ATP inhibits too little ATP stimulates Also controlled by citrate Oxidative accumulation inhibits phosphorylation keeps synchrony  Chapter 9 terms Aerobic respiration Cristae Fermentation Proton-motive force Redox reaction ATP-synthase Oxidation pH gradient Reduction Alcohol fermentation Reducing agent Lactic acid fermentation Oxidizing agent Anabolic pathways Anaerobic AMP/ADP Glycolysis Citric acid cycle Oxidative phosphorylation Electron transport chain Chemiosmosis Phosphofructokinase Pyruvate NAD+ Electron carrier