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Transcript
Figure 7.UN05 1. GLYCOLYSIS (color-coded blue throughout the chapter) 2. PYRUVATE OXIDATION and the CITRIC ACID CYCLE (color-coded orange) 3. OXIDATIVE PHOSPHORYLATION: Electron transport and chemiosmosis (color-coded purple) © 2017 Pearson Education, Ltd. Figure 7.6-s1 Electrons via NADH GLYCOLYSIS Glucose Pyruvate CYTOSOL ATP Substrate-level © 2017 Pearson Education, Ltd. MITOCHONDRION Figure 7.6-s2 Electrons via NADH and FADH2 Electrons via NADH GLYCOLYSIS Glucose Pyruvate CYTOSOL PYRUVATE OXIDATION Acetyl CoA CITRIC ACID CYCLE MITOCHONDRION ATP ATP Substrate-level Substrate-level © 2017 Pearson Education, Ltd. Figure 7.6-s3 Electrons via NADH and FADH2 Electrons via NADH GLYCOLYSIS Glucose Pyruvate CYTOSOL PYRUVATE OXIDATION Acetyl CoA CITRIC ACID CYCLE OXIDATIVE PHOSPHORYLATION (Electron transport and chemiosmosis) MITOCHONDRION ATP ATP ATP Substrate-level Substrate-level Oxidative © 2017 Pearson Education, Ltd. Oxidative phosphorylation accounts for almost 90% of the ATP generated by cellular respiration This process involves the transfer of inorganic phosphates to ADP © 2017 Pearson Education, Ltd. A smaller amount of ATP is formed in glycolysis and the citric acid cycle by substrate-level phosphorylation In this process, an enzyme transfers a phosphate group directly from a substrate molecule to ADP © 2017 Pearson Education, Ltd. For each molecule of glucose degraded to CO2 and water by respiration, the cell makes up to 32 molecules of ATP © 2017 Pearson Education, Ltd. Figure 7.7 Enzyme Enzyme ADP P Substrate ATP Product © 2017 Pearson Education, Ltd. Concept 7.2: Glycolysis harvests chemical energy by oxidizing glucose to pyruvate Glycolysis (“sugar splitting”) breaks down glucose into two molecules of pyruvate Glycolysis occurs in the cytoplasm and has two major phases Energy investment phase Energy payoff phase The net energy yield is 2 ATP plus 2 NADH per glucose molecule Glycolysis occurs whether or not O2 is present © 2017 Pearson Education, Ltd. Figure 7.UN06 GLYCOLYSIS ATP © 2017 Pearson Education, Ltd. PYRUVATE OXIDATION CITRIC ACID CYCLE OXIDATIVE PHOSPHORYLATION Figure 7.8 Energy Investment Phase Glucose 2 ATP used 2 ADP + 2 P Energy Payoff Phase 4 ADP + 4 P 2 NAD+ + 4 e + 4 H+ 4 ATP formed 2 NADH + 2 H+ 2 Pyruvate + 2 H2O Net Glucose 4 ATP formed 2 ATP used 2 NAD+ + 4 e + 4 H+ © 2017 Pearson Education, Ltd. 2 Pyruvate + 2 H2O 2 ATP 2 NADH + 2 H+ Figure 7.9-1 GLYCOLYSIS: Energy Investment Phase Glyceraldehyde 3-phosphate (G3P) Fructose ATP 6-phosphate Glucose 6-phosphate ATP Glucose ADP Fructose 1,6-bisphosphate ADP Isomerase Hexokinase © 2017 Pearson Education, Ltd. Phosphoglucoisomerase Phosphofructokinase Aldolase Dihydroxyacetone phosphate (DHAP) Figure 7.9-1a-s1 GLYCOLYSIS: Energy Investment Phase Glucose © 2017 Pearson Education, Ltd. Figure 7.9-1a-s2 GLYCOLYSIS: Energy Investment Phase Glucose 6-phosphate ATP Glucose ADP Hexokinase © 2017 Pearson Education, Ltd. Figure 7.9-1a-s3 GLYCOLYSIS: Energy Investment Phase Fructose 6-phosphate Glucose 6-phosphate ATP Glucose ADP Hexokinase © 2017 Pearson Education, Ltd. Phosphoglucoisomerase Figure 7.9-1b-s1 GLYCOLYSIS: Energy Investment Phase Fructose 6-phosphate © 2017 Pearson Education, Ltd. Figure 7.9-1b-s2 GLYCOLYSIS: Energy Investment Phase Fructose ATP 6-phosphate Fructose 1,6-bisphosphate ADP Phosphofructokinase © 2017 Pearson Education, Ltd. Figure 7.9-1b-s3 GLYCOLYSIS: Energy Investment Phase Glyceraldehyde 3-phosphate (G3P) Fructose ATP 6-phosphate Fructose 1,6-bisphosphate ADP Isomerase Phosphofructokinase © 2017 Pearson Education, Ltd. Aldolase Dihydroxyacetone phosphate (DHAP) Figure 7.9-2 GLYCOLYSIS: Energy Payoff Phase Glyceraldehyde 3-phosphate (G3P) 2 ATP 2 NADH 2 NAD+ + 2 H+ 2 ADP 2 H2O 2 2 2 2 ADP ATP 2 2 2 Triose phosphate dehydrogenase Phosphoglycerokinase 2 Pi 1,3-Bisphosphoglycerate © 2017 Pearson Education, Ltd. Phosphoglyceromutase 3-Phosphoglycerate 2-Phosphoglycerate Enolase Pyruvate kinase Phosphoenolpyruvate (PEP) Pyruvate Figure 7.9-2a-s1 GLYCOLYSIS: Energy Payoff Phase Glyceraldehyde 3-phosphate (G3P) Isomerase Aldolase Dihydroxyacetone phosphate (DHAP) © 2017 Pearson Education, Ltd. Figure 7.9-2a-s2 GLYCOLYSIS: Energy Payoff Phase Glyceraldehyde 3-phosphate (G3P) 2 NADH 2 NAD+ + 2 H+ 2 Isomerase Aldolase Dihydroxyacetone phosphate (DHAP) © 2017 Pearson Education, Ltd. Triose phosphate 2 dehydrogenase Pi 1,3-Bisphosphoglycerate Figure 7.9-2a-s3 GLYCOLYSIS: Energy Payoff Phase Glyceraldehyde 3-phosphate (G3P) 2 ATP 2 NADH 2 NAD+ 2 ADP + 2 H+ 2 2 Isomerase Aldolase Dihydroxyacetone phosphate (DHAP) © 2017 Pearson Education, Ltd. Triose phosphate 2 dehydrogenase Phosphoglycerokinase Pi 1,3-Bisphosphoglycerate 3-Phosphoglycerate Figure 7.9-2b-s1 GLYCOLYSIS: Energy Payoff Phase 2 3-Phosphoglycerate © 2017 Pearson Education, Ltd. Figure 7.9-2b-s2 GLYCOLYSIS: Energy Payoff Phase 2 H2O 2 2 2 Phosphoglyceromutase 3-Phosphoglycerate © 2017 Pearson Education, Ltd. Enolase 2-Phosphoglycerate Phosphoenolpyruvate (PEP) Figure 7.9-2b-s3 GLYCOLYSIS: Energy Payoff Phase 2 H2O 2 2 © 2017 Pearson Education, Ltd. ATP 2 Phosphoglyceromutase 3-Phosphoglycerate 2 2 ADP Pyruvate kinase Enolase 2-Phosphoglycerate 2 Phosphoenolpyruvate (PEP) Pyruvate Concept 7.3: After pyruvate is oxidized, the citric acid cycle completes the energy-yielding oxidation of organic molecules In the presence of O2, pyruvate enters the mitochondrion (in eukaryotic cells), where the oxidation of glucose is completed Before the citric acid cycle can begin, pyruvate must be converted to acetyl coenzyme A (acetyl CoA), which links glycolysis to the citric acid cycle © 2017 Pearson Education, Ltd. Figure 7.UN07 GLYCOLYSIS PYRUVATE OXIDATION CITRIC ACID CYCLE ATP © 2017 Pearson Education, Ltd. OXIDATIVE PHOSPHORYLATION Figure 7.10 Pyruvate (from glycolysis, 2 molecules per glucose) CYTOSOL PYRUVATE OXIDATION CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA CITRIC ACID CYCLE 3 NAD+ FADH2 3 NADH FAD ADP + P i ATP MITOCHONDRION © 2017 Pearson Education, Ltd. 2 CO2 + 3 H+ Figure 7.10-1 Pyruvate (from glycolysis, 2 molecules per glucose) CYTOSOL PYRUVATE OXIDATION CO2 NAD+ CoA NADH + H+ MITOCHONDRION © 2017 Pearson Education, Ltd. Acetyl CoA CoA Figure 7.10-2 Acetyl CoA CoA CoA CITRIC ACID CYCLE 3 NAD+ FADH2 FAD ADP + P i ATP MITOCHONDRION © 2017 Pearson Education, Ltd. 2 CO2 3 NADH + 3 H+ The citric acid cycle, also called the Krebs cycle, completes the breakdown of pyruvate to CO2 The cycle oxidizes organic fuel derived from pyruvate, generating 1 ATP, 3 NADH, and 1 FADH2 per turn © 2017 Pearson Education, Ltd. The citric acid cycle has eight steps, each catalyzed by a specific enzyme The 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 extracted from food to the electron transport chain © 2017 Pearson Education, Ltd. Figure 7.UN08 GLYCOLYSIS PYRUVATE OXIDATION CITRIC ACID CYCLE ATP © 2017 Pearson Education, Ltd. OXIDATIVE PHOSPHORYLATION Figure 7.11-s1 Acetyl CoA CoA-SH H2O Oxaloacetate Citrate CITRIC ACID CYCLE © 2017 Pearson Education, Ltd. Isocitrate Figure 7.11-s2 Acetyl CoA CoA-SH H2O Oxaloacetate Citrate CITRIC ACID CYCLE Isocitrate NAD+ NADH + H+ CO2 a-Ketoglutarate © 2017 Pearson Education, Ltd. Figure 7.11-s3 Acetyl CoA CoA-SH H2O Oxaloacetate Citrate Isocitrate NAD+ CITRIC ACID CYCLE NADH + H+ CO2 CoA-SH a-Ketoglutarate NAD+ NADH Succinyl CoA © 2017 Pearson Education, Ltd. + H+ CO2 Figure 7.11-s4 Acetyl CoA CoA-SH H2O Oxaloacetate Citrate Isocitrate NAD+ CITRIC ACID CYCLE NADH + H+ CO2 CoA-SH a-Ketoglutarate CoA-SH NAD+ Succinate GTP GDP ADP ATP © 2017 Pearson Education, Ltd. NADH Pi Succinyl CoA + H+ CO2 Figure 7.11-s5 Acetyl CoA CoA-SH H2O Oxaloacetate Citrate Isocitrate NAD+ CITRIC ACID CYCLE Fumarate NADH + H+ CO2 CoA-SH a-Ketoglutarate CoA-SH FADH2 NAD+ FAD Succinate GTP GDP ADP ATP © 2017 Pearson Education, Ltd. NADH Pi Succinyl CoA + H+ CO2 Figure 7.11-s6 Acetyl CoA CoA-SH NADH H2O + H+ NAD+ Oxaloacetate Malate Citrate Isocitrate NAD+ CITRIC ACID CYCLE H2O Fumarate NADH + H+ CO2 CoA-SH a-Ketoglutarate CoA-SH FADH2 NAD+ FAD Succinate GTP GDP ADP ATP © 2017 Pearson Education, Ltd. NADH Pi Succinyl CoA + H+ CO2 Figure 7.11-1 Start: Acetyl CoA adds its two-carbon group to oxaloacetate, producing citrate; this is a highly exergonic reaction. Acetyl CoA CoA-SH H2O Oxaloacetate Citrate Isocitrate © 2017 Pearson Education, Ltd. Figure 7.11-2 Isocitrate NAD+ NADH + H+ CO2 Redox reaction: Isocitrate is oxidized; NAD+ is reduced. CO2 release CoA-SH a-Ketoglutarate NAD+ Succinyl CoA © 2017 Pearson Education, Ltd. NADH + H+ CO2 CO2 release Redox reaction: After CO2 release, the resulting four-carbon molecule is oxidized (reducing NAD+), then made reactive by addition of CoA. Figure 7.11-3 Fumarate CoA-SH FADH2 Redox reaction: Succinate is oxidized; FAD is reduced. FAD Succinate GTP GDP ADP ATP formation © 2017 Pearson Education, Ltd. ATP Pi Succinyl CoA Figure 7.11-4 Redox reaction: Malate is oxidized; NAD+ is reduced. NADH + H+ NAD+ Oxaloacetate Malate H2O Fumarate © 2017 Pearson Education, Ltd. Concept 7.4: During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis 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 © 2017 Pearson Education, Ltd. The Pathway of Electron Transport The electron transport chain is located in the inner membrane (cristae) of the mitochondrion Most of the chain’s components are proteins, which exist in multiprotein complexes The carriers 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 © 2017 Pearson Education, Ltd. Electrons are transferred from NADH or FADH2 to the electron transport chain Electrons are passed through a number of proteins including cytochromes (each with an iron atom) to O2 The electron transport chain generates no ATP directly It breaks the large free-energy drop from food to O2 into smaller steps that release energy in manageable amounts © 2017 Pearson Education, Ltd. Figure 7.UN09 GLYCOLYSIS PYRUVATE OXIDATION CITRIC ACID CYCLE OXIDATIVE PHOSPHORYLATION ATP © 2017 Pearson Education, Ltd. Figure 7.12 (least electronegative) NADH Free energy (G) relative to O2 (kcal/mol) 50 2 e NAD+ FADH2 40 FMN 2 e FAD Fe•S II I Fe•S Q III Cyt b 30 Complexes I-IV Fe•S Cyt c1 IV Cyt c Cyt a Electron transport 20 chain 10 0 Cyt a3 2 e 2 H+ + ½ O 2 (most electronegative) H2O © 2017 Pearson Education, Ltd. Figure 7.12-1 (least electronegative) NADH Free energy (G) relative to O2 (kcal/mol) 50 NAD+ FADH2 40 FMN 2 e FAD Fe•S II Complexes I-IV I Fe•S Q III Cyt b Fe•S 30 Cyt c1 IV Cyt c Cyt a 20 10 © 2017 Pearson Education, Ltd. 2 e Electron transport chain Cyt a3 2 e Free energy (G) relative to O2 (kcal/mol) Figure 7.12-2 Fe•S 30 Cyt c1 IV Cyt c Electron transport chain 20 10 0 Cyt a Cyt a3 2 e 2 H+ + ½ O2 (most electronegative) H2O © 2017 Pearson Education, Ltd. Chemiosmosis: The Energy-Coupling Mechanism 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 the protein complex, 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 © 2017 Pearson Education, Ltd. Video: ATP Synthase 3-D Side View © 2017 Pearson Education, Ltd. Video: ATP Synthase 3-D Top View © 2017 Pearson Education, Ltd. Figure 7.13 Intermembrane space Mitochondrial matrix Inner mitochondrial membrane INTERMEMBRANE SPACE H+ Stator Rotor Internal rod Catalytic knob ADP + Pi ATP MITOCHONDRIAL MATRIX (a) The ATP synthase protein complex © 2017 Pearson Education, Ltd. (b) Computer model of ATP synthase Figure 7.13-1 H+ INTERMEMBRANE SPACE Stator Rotor Internal rod Catalytic knob ADP + MITOCHONDRIAL MATRIX Pi (a) The ATP synthase protein complex © 2017 Pearson Education, Ltd. ATP Figure 7.13-2 (b) Computer model of ATP synthase © 2017 Pearson Education, Ltd. The 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, emphasizing its capacity to do work © 2017 Pearson Education, Ltd. Figure 7.UN09 GLYCOLYSIS PYRUVATE OXIDATION CITRIC ACID CYCLE OXIDATIVE PHOSPHORYLATION ATP © 2017 Pearson Education, Ltd. Figure 7.14 H+ H+ H+ H+ Cyt c Protein complex of electron carriers IV Q III I II FADH2 FAD NADH ATP synthase 2 H+ + ½ O2 H 2O NAD+ ADP + P i (carrying electrons from food) H+ Electron transport chain Oxidative phosphorylation © 2017 Pearson Education, Ltd. ATP Chemiosmosis Figure 7.14-1 H+ H+ H+ Cyt c Protein complex of electron carriers IV Q III I II FADH2 FAD 2 H+ + ½ O2 NAD+ NADH (carrying electrons from food) Electron transport chain © 2017 Pearson Education, Ltd. H2O Figure 7.14-2 ATP synthase H+ ADP + P i ATP H+ Chemiosmosis © 2017 Pearson Education, Ltd. An Accounting of ATP Production by Cellular Respiration During cellular respiration, most energy flows in the following sequence: glucose NADH electron transport chain protonmotive force ATP About 34% of the energy in a glucose molecule is transferred to ATP during cellular respiration, making about 32 ATP There are several reasons why the number of ATP molecules is not known exactly © 2017 Pearson Education, Ltd. Figure 7.15 CYTOSOL Electron shuttles span membrane 2 NADH GLYCOLYSIS Glucose 2 Pyruvate MITOCHONDRION 2 NADH or 2 FADH2 2 NADH PYRUVATE OXIDATION 2 Acetyl CoA + 2 ATP CITRIC ACID CYCLE + 2 ATP Maximum per glucose: © 2017 Pearson Education, Ltd. 6 NADH About 30 or 32 ATP 2 FADH2 OXIDATIVE PHOSPHORYLATION (Electron transport and chemiosmosis) + about 26 or 28 ATP Figure 7.15-1 Electron shuttles span membrane 2 NADH GLYCOLYSIS Glucose 2 Pyruvate + 2 ATP © 2017 Pearson Education, Ltd. 2 NADH or 2 FADH2 Figure 7.15-2 2 NADH PYRUVATE OXIDATION 2 Acetyl CoA 6 NADH CITRIC ACID CYCLE + 2 ATP © 2017 Pearson Education, Ltd. 2 FADH2 Figure 7.15-3 2 NADH or 2 FADH2 2 NADH 6 NADH 2 FADH2 OXIDATIVE PHOSPHORYLATION (Electron transport and chemiosmosis) + about 26 or 28 ATP © 2017 Pearson Education, Ltd. Figure 7.15-4 Maximum per glucose: © 2017 Pearson Education, Ltd. About 30 or 32 ATP Concept 7.5: Fermentation and anaerobic respiration enable cells to produce ATP without the use of oxygen Most cellular respiration requires O2 to produce ATP Without O2, the electron transport chain will cease to operate In that case, glycolysis couples with fermentation or anaerobic respiration to produce ATP © 2017 Pearson Education, Ltd. Anaerobic respiration uses an electron transport chain with a final electron acceptor other than O2, for example, sulfate Fermentation uses substrate-level phosphorylation instead of an electron transport chain to generate ATP © 2017 Pearson Education, Ltd. Types of Fermentation Fermentation consists of glycolysis plus reactions that regenerate NAD+, which can be reused by glycolysis Two common types are alcohol fermentation and lactic acid fermentation © 2017 Pearson Education, Ltd. In alcohol fermentation, pyruvate is converted to ethanol in two steps The first step releases CO2 from pyruvate, and the second step reduces the resulting acetaldehyde to ethanol Alcohol fermentation by yeast is used in brewing, winemaking, and baking © 2017 Pearson Education, Ltd. Animation: Fermentation Overview © 2017 Pearson Education, Ltd. Figure 7.16-1 2 ADP + 2 P i Glucose 2 ATP GLYCOLYSIS 2 Pyruvate 2 NAD+ 2 Ethanol (a) Alcohol fermentation © 2017 Pearson Education, Ltd. 2 NADH + 2 H+ 2 CO2 2 Acetaldehyde In lactic acid fermentation, pyruvate is reduced by NADH, forming lactate as an end product, with no release of CO2 Lactic acid fermentation by some fungi and bacteria is used to make cheese and yogurt Human muscle cells use lactic acid fermentation to generate ATP when O2 is scarce © 2017 Pearson Education, Ltd. Figure 7.16-2 2 ADP + 2 P i Glucose 2 ATP GLYCOLYSIS 2 NAD+ 2 NADH + 2 H+ 2 Pyruvate 2 Lactate (b) Lactic acid fermentation © 2017 Pearson Education, Ltd. Figure 7.16 2 ADP + 2 P i Glucose 2 2 ADP + 2 P i ATP GLYCOLYSIS Glucose 2 ATP GLYCOLYSIS 2 Pyruvate 2 NAD+ 2 Ethanol (a) Alcohol fermentation © 2017 Pearson Education, Ltd. 2 NADH + 2 H+ 2 NAD+ 2 CO2 2 Acetaldehyde 2 NADH + 2 H+ 2 Lactate (b) Lactic acid fermentation 2 Pyruvate Comparing Fermentation with Anaerobic and Aerobic Respiration All use glycolysis (net ATP = 2) to oxidize glucose and other organic fuels to pyruvate In all three, NAD+ is the oxidizing agent that accepts electrons from food during glycolysis The mechanism of NADH oxidation differs In fermentation the final electron acceptor is an organic molecule such as pyruvate or acetaldehyde Cellular respiration transfers electrons from NADH to a carrier molecule in the electron transport chain © 2017 Pearson Education, Ltd. Cellular respiration produces about 32 ATP per glucose molecule; fermentation produces 2 ATP per glucose molecule © 2017 Pearson Education, Ltd. Obligate anaerobes carry out only fermentation or anaerobic respiration and cannot survive in the presence of O2 Yeast and many bacteria are facultative anaerobes, meaning that they can survive using either fermentation or cellular respiration In a facultative anaerobe, pyruvate is a fork in the metabolic road that leads to two alternative catabolic routes © 2017 Pearson Education, Ltd. Figure 7.17 Glucose CYTOSOL Glycolysis Pyruvate No O2 present: Fermentation O2 present: Aerobic cellular respiration MITOCHONDRION Ethanol, lactate, or other products Acetyl CoA CITRIC ACID CYCLE © 2017 Pearson Education, Ltd. The Evolutionary Significance of Glycolysis Glycolysis is the most common metabolic pathway among organisms on Earth, indicating that it evolved early in the history of life Early prokaryotes may have generated ATP exclusively through glycolysis due to the low oxygen content in the atmosphere The location of glycolysis in the cytosol also indicates its ancient origins; eukaryotic cells with mitochondria evolved much later than prokaryotic cells © 2017 Pearson Education, Ltd. Concept 7.6: Glycolysis and the citric acid cycle connect to many other metabolic pathways Glycolysis and the citric acid cycle are major intersections to various catabolic and anabolic pathways © 2017 Pearson Education, Ltd. The Versatility of Catabolism Catabolic pathways funnel electrons from many kinds of organic molecules into cellular respiration Glycolysis accepts a wide range of carbohydrates Proteins must be digested to amino acids and amino groups must be removed before amino acids can feed glycolysis or the citric acid cycle © 2017 Pearson Education, Ltd. Fats are digested to glycerol (used in glycolysis) and fatty acids 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 © 2017 Pearson Education, Ltd. Figure 7.18-s1 Proteins Carbohydrates Amino acids Sugars © 2017 Pearson Education, Ltd. Fats Glycerol Fatty acids Figure 7.18-s2 Proteins Carbohydrates Amino acids Sugars GLYCOLYSIS Glucose Glyceraldehyde 3- P NH3 © 2017 Pearson Education, Ltd. Pyruvate Fats Glycerol Fatty acids Figure 7.18-s3 Proteins Carbohydrates Amino acids Sugars GLYCOLYSIS Glucose Glyceraldehyde 3- P NH3 Pyruvate Acetyl CoA © 2017 Pearson Education, Ltd. Fats Glycerol Fatty acids Figure 7.18-s4 Proteins Carbohydrates Amino acids Sugars GLYCOLYSIS Glucose Glyceraldehyde 3- P NH3 Pyruvate Acetyl CoA CITRIC ACID CYCLE © 2017 Pearson Education, Ltd. Fats Glycerol Fatty acids Figure 7.18-s5 Proteins Carbohydrates Amino acids Sugars Fats Glycerol Fatty acids GLYCOLYSIS Glucose Glyceraldehyde 3- P NH3 Pyruvate Acetyl CoA CITRIC ACID CYCLE © 2017 Pearson Education, Ltd. OXIDATIVE PHOSPHORYLATION Biosynthesis (Anabolic Pathways) The body uses small molecules to build other substances Some of these small molecules come directly from food; others can be produced during glycolysis or the citric acid cycle © 2017 Pearson Education, Ltd. Figure 7.UN10-1 © 2017 Pearson Education, Ltd. Figure 7.UN10-2 © 2017 Pearson Education, Ltd. Figure 7.UN11 Inputs Outputs GLYCOLYSIS Glucose © 2017 Pearson Education, Ltd. 2 Pyruvate 2 ATP 2 NADH Figure 7.UN12 Inputs 2 Pyruvate 2 Acetyl CoA 2 Oxaloacetate © 2017 Pearson Education, Ltd. Outputs CITRIC ACID CYCLE 2 ATP 6 CO2 2 FADH2 8 NADH Figure 7.UN13 H+ H+ IV Q III I II FA DH2 FAD NAD+ (carrying electrons from food) © 2017 Pearson Education, Ltd. H+ Cyt c Protein complex of electron carriers NADH INTERMEMBRANE SPACE 2 H+ + ½ O2 MITOCHONDRIAL MATRIX H2O Figure 7.UN14 INTERMEMBRANE SPACE H+ MITO CHONDRIAL MATRIX ADP + P i © 2017 Pearson Education, Ltd. ATP synthase H+ ATP pH difference across membrane Figure 7.UN15 © 2017 Pearson Education, Ltd. Time Phosphofructokinase activity Figure 7.UN16 Low ATP concentration High ATP concentration Fructose 6-phosphate concentration © 2017 Pearson Education, Ltd. Figure 7.UN17 © 2017 Pearson Education, Ltd.
