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Cellular Respiration: Harvesting Chemical Energy
Chapter 9 Cellular Respiration: Harvesting Chemical Energy
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Living cells require energy from outside sources
Overview: Life Is Work Living cells require energy from outside sources Where do they get this? For the Discovery Video Space Plants, go to Animation and Video Files. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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To Review Energy flows into an ecosystem as sunlight and leaves as heat Photosynthesis generates O2 and organic molecules, which are used in cellular respiration Cells use chemical energy stored in organic molecules to regenerate ATP, which powers work Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Organic molecules Cellular respiration in mitochondria
Fig. 9-2 Light energy ECOSYSTEM Photosynthesis in chloroplasts Organic molecules CO2 + H2O + O2 Cellular respiration in mitochondria Figure 9.2 Energy flow and chemical recycling in ecosystems ATP ATP powers most cellular work Heat energy
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The ways energy is transformed can be done by many different factors.
Concept 9.1: Catabolic pathways yield energy by oxidizing organic fuels The ways energy is transformed can be done by many different factors. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Catabolic Pathways and Production of ATP
Breakdown of organic molecules is exergonic What does this mean? Fermentation: Partial degradation of sugars that occurs without O2 Aerobic Respiration: Consumes organic molecules and O2 and yields ATP Anaerobic Respiration: Similar to aerobic respiration but consumes compounds other than O2 Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Catabolic Pathways and Production of ATP Cont’d
Cellular Respiration: Includes both aerobic and anaerobic respiration but is often used to refer to aerobic respiration Although carbohydrates, fats, and proteins are all consumed as fuel, it is helpful to trace cellular respiration with the sugar glucose: C6H12O6 + 6 O2 6 CO2 + 6 H2O + Energy (ATP + heat) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Redox Reactions: Oxidation and Reduction
What ultimately causes energy to be released in chemical reactions? Transfer of electrons during chemical reactions does this This is what makes ATP Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Substance loses electrons, or is oxidized Reduction
The Principle of Redox Redox Reactions Chemical reaction that transfers electrons between reactants are also called oxidation-reduction reactions Oxidation Substance loses electrons, or is oxidized Reduction Substance gains electrons, or is reduced (the amount of positive charge is reduced) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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becomes oxidized (loses electron) becomes reduced (gains electron)
Fig. 9-UN1 becomes oxidized (loses electron) becomes reduced (gains electron)
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becomes oxidized becomes reduced
Fig. 9-UN2 becomes oxidized becomes reduced
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The Principle of Redox Cont’d
Reducing Agent: Electron Donor Oxidizing Agent: Electron Receptor Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Oxidation of Organic Fuel Molecules During Cellular Respiration
During cellular respiration, the fuel (such as glucose) is oxidized, and O2 is reduced: Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Fig. 9-UN3 becomes oxidized becomes reduced
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Stepwise Energy Harvest via NAD+ and the Electron Transport Chain
Steps to organic molecules being broken down Electrons from organic compounds are usually first transferred to NAD+, (coenzyme) NAD+ (electron acceptor), functions as an oxidizing agent during cellular respiration Each NADH (the reduced form of NAD+) represents stored energy that is tapped to synthesize ATP Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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NADH H+ NAD+ + 2[H] + H+ 2 e– + 2 H+ 2 e– + H+ Dehydrogenase
Fig. 9-4 2 e– + 2 H+ 2 e– + H+ NADH H+ Dehydrogenase Reduction of NAD+ NAD+ + 2[H] + H+ Oxidation of NADH Nicotinamide (reduced form) Nicotinamide (oxidized form) Figure 9.4 NAD+ as an electron shuttle
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Stepwise Energy Harvest via NAD+ and the Electron Transport Chain Cont’d
NADH passes the electrons to the electron transport chain ETC passes electrons down in a series of steps instead of one explosive reaction Why is this important? B/C like a gas tank in a car if it explodes the car cannot go anywhere but when the gas is slowly burned motion can take place O2 pulls electrons down the chain in an energy-yielding tumble The energy yielded is used to regenerate ATP Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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(a) Uncontrolled reaction (b) Cellular respiration
Fig. 9-5 H2 + 1/2 O2 2 H + 1/2 O2 (from food via NADH) Controlled release of energy for synthesis of ATP 2 H e– ATP Explosive release of heat and light energy ATP Electron transport chain Free energy, G Free energy, G ATP 2 e– 1/2 O2 Figure 9.5 An introduction to electron transport chains 2 H+ H2O H2O (a) Uncontrolled reaction (b) Cellular respiration
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The Stages of Cellular Respiration: A Preview
3 Stages of Cell Respiration Glycolysis (breaks down glucose into two molecules of pyruvate) Citric Acid Cycle (completes the breakdown of glucose) Oxidative phosphorylation (accounts for most of the ATP synthesis) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Electrons carried via NADH Electrons carried via NADH and FADH2
Fig Electrons carried via NADH Electrons carried via NADH and FADH2 Oxidative phosphorylation: electron transport and chemiosmosis Glycolysis Citric acid cycle Glucose Pyruvate Mitochondrion Cytosol Figure 9.6 An overview of cellular respiration ATP ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation Oxidative phosphorylation
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Overview to Cell Respiration
Oxidative Phosphorylation Process that generates most of the ATP and is powered by redox reactions Accounts for almost 90% of the ATP generated by cellular respiration Substrate-Level Phosphorylation Process that generates a small amount of ATP Occurs in Glycolysis and the Citric Acid Cycle BioFlix: Cellular Respiration Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Substrate-Level Phosphorylation
Fig. 9-7 Substrate-Level Phosphorylation Enzyme Enzyme ADP P Substrate + ATP Figure 9.7 Substrate-level phosphorylation Product
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Glycolysis (“splitting of sugar”)
Concept 9.2: Glycolysis harvests 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
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Energy investment phase
Fig. 9-8 Energy investment phase Glucose 2 ADP + 2 P 2 ATP used Energy payoff phase 4 ADP + 4 P 4 ATP formed 2 NAD e– + 4 H+ 2 NADH + 2 H+ Figure 9.8 The energy input and output of glycolysis 2 Pyruvate + 2 H2O Net Glucose 2 Pyruvate + 2 H2O 4 ATP formed – 2 ATP used 2 ATP 2 NAD e– + 4 H+ 2 NADH + 2 H+
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Summary of Glycoloysis
Energy Yielded= 2 ATP and 2 NADH 2 molecules of Pyruvate are formed No CO2 is released Will occur if O2 is present or not If present, energy stored in Pyruvate and NADH can be extracted by the next step in CR
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Glycolysis Movie
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If O2 is present, pyruvate will enter the mitochondrion
Concept 9.3: The citric acid cycle completes the energy-yielding oxidation of organic molecules If O2 is present, pyruvate will enter the mitochondrion Pyruvate must be converted to acetyl CoA before the next phase can begin Known as the Citric Acid Cycle Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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How does this conversion take place?
Fig. 9-10 How does this conversion take place? CYTOSOL MITOCHONDRION NAD+ NADH + H+ 2 1 3 Acetyl CoA Figure 9.10 Conversion of pyruvate to acetyl CoA, the junction between glycolysis and the citric acid cycle Pyruvate Coenzyme A CO2 Transport protein
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Overview to 2nd Step of Cell Respiration
2 Names: Citric Acid Cycle or Krebs Cycle Location: Within the mitochondrial matrix Purpose: To oxidizes organic fuel derived from pyruvate Generates: 2 ATP, 6 NADH, and 2 FADH2 Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA Citric acid cycle 2
Fig. 9-11 Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA Citric acid cycle 2 CO2 Figure 9.11 An overview of the citric acid cycle FADH2 3 NAD+ FAD 3 NADH + 3 H+ ADP + P i ATP
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Citric Acid Cycle Has eight steps, each catalyzed by a specific enzyme
Acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate, forming citrate The next seven steps decompose the citrate back to oxaloacetate, making the process a cycle The NADH and FADH2 produced by the cycle relay electrons to the electron transport chain The next step in Cell Respiration is where the majority of ATP is created Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Figure 9.12 A closer look at the citric acid cycle
Acetyl CoA CoA—SH 1 Oxaloacetate Citrate Citric acid cycle Figure 9.12 A closer look at the citric acid cycle
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Figure 9.12 A closer look at the citric acid cycle
Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate Citric acid cycle Figure 9.12 A closer look at the citric acid cycle
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Figure 9.12 A closer look at the citric acid cycle
Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric acid cycle NADH 3 + H+ CO2 -Keto- glutarate Figure 9.12 A closer look at the citric acid cycle
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Citric acid cycle Succinyl CoA
Fig Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric acid cycle NADH 3 + H+ CO2 CoA—SH -Keto- glutarate Figure 9.12 A closer look at the citric acid cycle 4 CO2 NAD+ NADH Succinyl CoA + H+
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Citric acid cycle Succinyl CoA
Fig Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric acid cycle NADH 3 + H+ CO2 CoA—SH -Keto- glutarate Figure 9.12 A closer look at the citric acid cycle 4 CoA—SH 5 CO2 NAD+ Succinate P NADH i GTP GDP Succinyl CoA + H+ ADP ATP
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Citric acid cycle Succinyl CoA
Fig Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Citrate Isocitrate NAD+ Citric acid cycle NADH 3 + H+ CO2 Fumarate CoA—SH -Keto- glutarate Figure 9.12 A closer look at the citric acid cycle 6 4 CoA—SH FADH2 5 CO2 NAD+ FAD Succinate P NADH i GTP GDP Succinyl CoA + H+ ADP ATP
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Citric acid cycle Succinyl CoA
Fig Acetyl CoA CoA—SH 1 H2O Oxaloacetate 2 Malate Citrate Isocitrate NAD+ Citric acid cycle NADH 3 7 + H+ H2O CO2 Fumarate CoA—SH -Keto- glutarate Figure 9.12 A closer look at the citric acid cycle 6 4 CoA—SH FADH2 5 CO2 NAD+ FAD Succinate P P NADH i GTP GDP Succinyl CoA + H+ ADP ATP
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Citric acid cycle Succinyl CoA
Fig Acetyl CoA CoA—SH NADH +H+ 1 H2O NAD+ 8 Oxaloacetate 2 Malate Citrate Isocitrate NAD+ Citric acid cycle NADH 3 7 + H+ H2O CO2 Fumarate CoA—SH -Keto- glutarate Figure 9.12 A closer look at the citric acid cycle 4 6 CoA—SH FADH2 5 CO2 NAD+ FAD Succinate P NADH i GTP GDP Succinyl CoA + H+ ADP ATP
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Citric Acid Cycle Movie
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NADH and FADH2 account for most of the energy extracted from food
Concept 9.4: During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis NADH and FADH2 account for most of the energy extracted from food These two electron carriers donate electrons to the electron transport chain This powers ATP synthesis via oxidative phosphorylation For the Cell Biology Video ATP Synthase 3D Structure — Side View, go to Animation and Video Files. For the Cell Biology Video ATP Synthase 3D Structure — Top View, go to Animation and Video Files. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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The Pathway of Electron Transport
ETC is in the cristae of the mitochondrion Most of the chain’s components are proteins The carriers (NADH & FADH2) alternate reduced and oxidized states as they accept and donate electrons Electrons drop in free energy as they go down the chain and are finally passed to O2, forming H2O Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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The Pathway of Electron Transport Cont’d
ETC generates no ATP Function: Break the large free-energy drop from food to O2 into smaller steps that release energy in manageable amounts Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Chemiosmosis: The Energy-Coupling Mechanism
Electron transfer causes proteins to pump H+ from the mitochondrial matrix to the intermembrane space H+ then move back across the membrane, passing through channels in ATP synthase ATP synthase uses the exergonic flow of H+ to drive phosphorylation of ATP Chemiosmosis, the use of energy in a H+ gradient to drive cellular work Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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INTERMEMBRANE SPACE H+ Stator Rotor Internal rod Cata- lytic knob ADP
Fig. 9-14 INTERMEMBRANE SPACE H+ Stator Rotor Internal rod Figure 9.14 ATP synthase, a molecular mill Cata- lytic knob ADP + P ATP i MITOCHONDRIAL MATRIX
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The H+ gradient is referred to as a proton-motive force:
Energy stored in a H+ gradient across a membrane couples the redox reactions of the electron transport chain to ATP synthesis The H+ gradient is referred to as a proton-motive force: Potential energy stored in the form of this electrochemical gradient of these H+ ions Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Electron transport chain 2 Chemiosmosis
Fig. 9-16 H+ H+ H+ H+ Protein complex of electron carriers Cyt c V Q ATP synthase 2 H+ + 1/2O2 H2O FADH2 FAD NADH NAD+ ADP + P ATP Figure 9.16 Chemiosmosis couples the electron transport chain to ATP synthesis i (carrying electrons from food) H+ 1 Electron transport chain 2 Chemiosmosis Oxidative phosphorylation
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An Accounting of ATP Production by Cellular Respiration
During cellular respiration, most energy flows in this sequence: glucose NADH/FADH2 electron transport chain proton-motive force ATP About 40% of the energy in a glucose molecule is transferred to ATP during cellular respiration Making about 36 or 38 ATP Figure 9.17 sums the entire process up Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Fig. 9-17 CYTOSOL Electron shuttles span membrane MITOCHONDRION 2 NADH or 2 FADH2 2 NADH 2 NADH 6 NADH 2 FADH2 Glycolysis Oxidative phosphorylation: electron transport and chemiosmosis 2 Pyruvate 2 Acetyl CoA Citric acid cycle Glucose + 2 ATP + 2 ATP + about 32 or 34 ATP Figure 9.17 ATP yield per molecule of glucose at each stage of cellular respiration About 36 or 38 ATP Maximum per glucose:
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Cell Respiration Video
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Most cellular respiration requires O2 to produce ATP However
Concept 9.5: Fermentation and anaerobic respiration enable cells to produce ATP without the use of oxygen Most cellular respiration requires O2 to produce ATP However Glycolysis can produce ATP with or without O2 (in aerobic or anaerobic conditions) In the absence of O2, glycolysis couples with fermentation or anaerobic respiration to produce ATP Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Anaerobic Respiration
Without O2…. Anaerobic Respiration Uses an electron transport chain with an electron acceptor other than O2, Ex.) sulfate Fermentation Uses phosphorylation instead of an electron transport chain to generate ATP Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Fermentation consists of glycolysis plus reactions that regenerate NAD
Types of Fermentation Fermentation consists of glycolysis plus reactions that regenerate NAD Two common types: Alcohol Fermentation Lactic Acid Fermentation Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Animation: Fermentation Overview
Alcohol Fermentation Pyruvate is converted to ethanol in two steps, with the first releasing CO2 Alcohol fermentation by yeast is used in brewing, winemaking, and baking Animation: Fermentation Overview Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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(a) Alcohol fermentation
Fig. 9-18a 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 Pyruvate 2 NAD+ 2 NADH 2 CO2 + 2 H+ Figure 9.18a Fermentation 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation
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Lactic Acid Fermentation
Pyruvate is reduced to NADH, forming lactate as an end product, with no release of CO2 Some fungi and bacteria are used to make cheese and yogurt by using this process Human muscle cells use lactic acid fermentation to generate ATP when O2 is scarce Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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(b) Lactic acid fermentation
Fig. 9-18b 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 NAD+ 2 NADH + 2 H+ 2 Pyruvate Figure 9.18b Fermentation 2 Lactate (b) Lactic acid fermentation
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Fermentation and Aerobic Respiration Compared
Both processes use glycolysis to oxidize glucose and other organic fuels to pyruvate The processes have different final electron acceptors: Organic molecule (such as pyruvate or acetaldehyde) in fermentation and O2 in cellular respiration Cellular respiration produces 38 or 36 ATP per glucose molecule Fermentation produces 2 ATP per glucose molecule Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Special Types of Organisms
Obligate Anaerobes Carry out fermentation and cannot survive in the presence of O2 Ex.) Clostridium Bacteroides Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Special Types of Organisms Cont’d
Facultative Anaerobes Can survive using either fermentation or cellular respiration Ex.) Yeast and many Bacteria Here is why they can do either: Pyruvate is a fork in the metabolic road that leads to two alternative catabolic routes Fig 9.19 shows this p.179
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Ethanol or lactate Citric acid cycle
Fig. 9-19 Glucose Glycolysis CYTOSOL Pyruvate O2 present: Aerobic cellular respiration No O2 present: Fermentation MITOCHONDRION Ethanol or lactate Acetyl CoA Figure 9.19 Pyruvate as a key juncture in catabolism Citric acid cycle
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The Evolutionary Significance of Glycolysis
Glycolysis occurs in nearly all organisms Glycolysis probably evolved in ancient prokaryotes before there was oxygen in the atmosphere Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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They are not just isolated events
Concept 9.6: Glycolysis and the citric acid cycle connect to many other metabolic pathways Gycolysis and the citric acid cycle are major intersections to various catabolic and anabolic pathways They are not just isolated events Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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The Versatility of Catabolism
Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration Glycolysis accepts a wide range of carbohydrates Ex.) Proteins must be digested to amino acids; amino groups can feed glycolysis or the citric acid cycle Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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The Versatility of Catabolism Cont’d
Fats are digested to glycerol (used in glycolysis) and fatty acids (used in generating acetyl CoA) Fatty acids are broken down by beta oxidation and yield acetyl CoA An oxidized gram of fat produces more than twice as much ATP as an oxidized gram of carbohydrate Fig shows how each macromolecule can be broken down and then fed into CR Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Fig. 9-20 Proteins Carbohydrates Fats Amino acids Sugars Glycerol
Fatty acids Glycolysis Glucose Glyceraldehyde-3- P NH3 Pyruvate Acetyl CoA Figure 9.20 The catabolism of various molecules from food Citric acid cycle Oxidative phosphorylation
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Biosynthesis (Anabolic Pathways)
Not all organic molecules are used in ATP production Body uses small molecules to build other substances Ex.) Certain proteins an be produced from certain foods that the body needs Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Regulation of Cellular Respiration via Feedback Mechanisms
Feedback inhibition is the most common mechanism for control ATP concentration begins to drop = respiration speeds up Plenty of ATP = respiration slows down Control of catabolism is based mainly on regulating the activity of enzymes at strategic points in the catabolic pathway Fig Shows how CR can be controlled Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Figure 9.21 The control of cellular respiration
Glucose AMP Glycolysis Fructose-6-phosphate Stimulates + Phosphofructokinase – – Fructose-1,6-bisphosphate Inhibits Inhibits Pyruvate ATP Citrate Acetyl CoA Figure 9.21 The control of cellular respiration Citric acid cycle Oxidative phosphorylation
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The End
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Fig. 9-UN5 Inputs Outputs 2 ATP Glycolysis + 2 NADH Glucose 2 Pyruvate
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Inputs Outputs S—CoA 2 ATP C O CH3 2 Acetyl CoA 6 NADH O C COO
Fig. 9-UN6 Inputs Outputs S—CoA 2 ATP C O CH3 2 Acetyl CoA 6 NADH O C COO Citric acid cycle CH2 2 FADH2 COO 2 Oxaloacetate
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INTER- MEMBRANE SPACE H+ ATP synthase ADP + P ATP MITO- CHONDRIAL
Fig. 9-UN7 INTER- MEMBRANE SPACE H+ ATP synthase ADP + P ATP i MITO- CHONDRIAL MATRIX H+
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Fig. 9-UN8 across membrane pH difference Time
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Fig. 9-UN9
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You should now be able to:
Explain in general terms how redox reactions are involved in energy exchanges Name the three stages of cellular respiration; for each, state the region of the eukaryotic cell where it occurs and the products that result In general terms, explain the role of the electron transport chain in cellular respiration Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Distinguish between fermentation and anaerobic respiration
Explain where and how the respiratory electron transport chain creates a proton gradient Distinguish between fermentation and anaerobic respiration Distinguish between obligate and facultative anaerobes Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
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Glucose ATP 1 Hexokinase ADP Glucose-6-phosphate Fig. 9-9-1
Figure 9.9 A closer look at glycolysis Glucose-6-phosphate
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Glucose-6-phosphate 2 Phosphogluco- isomerase Fructose-6-phosphate
Fig Glucose ATP 1 Hexokinase ADP Glucose-6-phosphate Glucose-6-phosphate 2 Phosphoglucoisomerase 2 Phosphogluco- isomerase Fructose-6-phosphate Figure 9.9 A closer look at glycolysis Fructose-6-phosphate
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Fructose- 1, 6-bisphosphate
Fig Glucose ATP 1 1 Hexokinase ADP Fructose-6-phosphate Glucose-6-phosphate 2 2 Phosphoglucoisomerase ATP 3 Phosphofructo- kinase Fructose-6-phosphate ATP 3 3 ADP Phosphofructokinase ADP Figure 9.9 A closer look at glycolysis Fructose- 1, 6-bisphosphate Fructose- 1, 6-bisphosphate
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Aldolase Isomerase Fructose- 1, 6-bisphosphate 4 5 Dihydroxyacetone
Fig Glucose ATP 1 Hexokinase ADP Glucose-6-phosphate 2 Phosphoglucoisomerase Fructose- 1, 6-bisphosphate 4 Fructose-6-phosphate Aldolase ATP 3 Phosphofructokinase ADP 5 Figure 9.9 A closer look at glycolysis Isomerase Fructose- 1, 6-bisphosphate 4 Aldolase 5 Isomerase Dihydroxyacetone phosphate Glyceraldehyde- 3-phosphate Dihydroxyacetone phosphate Glyceraldehyde- 3-phosphate
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Glyceraldehyde- 3-phosphate
Fig 2 NAD+ 6 Triose phosphate dehydrogenase 2 NADH 2 P i + 2 H+ 2 2 1, 3-Bisphosphoglycerate Glyceraldehyde- 3-phosphate 2 NAD+ 6 Triose phosphate dehydrogenase 2 P 2 NADH i + 2 H+ Figure 9.9 A closer look at glycolysis 2 1, 3-Bisphosphoglycerate
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2 2 ADP 2 ATP 2 3-Phosphoglycerate 1, 3-Bisphosphoglycerate 7
Fig 2 NAD+ 6 Triose phosphate dehydrogenase 2 NADH 2 P i + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 1, 3-Bisphosphoglycerate 2 ADP 2 3-Phosphoglycerate 7 Phosphoglycero- kinase 2 ATP Figure 9.9 A closer look at glycolysis 2 3-Phosphoglycerate
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2 3-Phosphoglycerate 8 Phosphoglycero- mutase 2 2-Phosphoglycerate
Fig 2 NAD+ 6 Triose phosphate dehydrogenase 2 NADH 2 P i + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 3-Phosphoglycerate 2 3-Phosphoglycerate 8 Phosphoglyceromutase 8 Phosphoglycero- mutase 2 2-Phosphoglycerate Figure 9.9 A closer look at glycolysis 2 2-Phosphoglycerate
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2 2-Phosphoglycerate Enolase 2 H2O 2 Phosphoenolpyruvate 9 Fig. 9-9-8
2 NAD+ 6 Triose phosphate dehydrogenase 2 NADH 2 P i + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 2-Phosphoglycerate 2 3-Phosphoglycerate 8 Phosphoglyceromutase 9 Enolase 2 H2O 2 2-Phosphoglycerate 9 Enolase 2 H2O Figure 9.9 A closer look at glycolysis 2 Phosphoenolpyruvate 2 Phosphoenolpyruvate
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2 Phosphoenolpyruvate 2 ADP 10 Pyruvate kinase 2 ATP 2 Pyruvate
Fig 2 NAD+ 6 Triose phosphate dehydrogenase 2 NADH 2 P i + 2 H+ 2 1, 3-Bisphosphoglycerate 2 ADP 7 Phosphoglycerokinase 2 ATP 2 Phosphoenolpyruvate 2 ADP 2 3-Phosphoglycerate 8 10 Phosphoglyceromutase Pyruvate kinase 2 ATP 2 2-Phosphoglycerate 9 Enolase 2 H2O Figure 9.9 A closer look at glycolysis 2 Phosphoenolpyruvate 2 ADP 10 Pyruvate kinase 2 ATP 2 Pyruvate 2 Pyruvate
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