Respiration

Breathing and Respiration Cellular Aerobic Respiration Efficiency of Respiration Cellular Anaerobic Respiration Respiration of Carbohydrate, Protein & Fat Outline – Cellular Respiration

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings CO 2 O2O2 Bloodstream Muscle cells Cellular Respiration Breathing Glucose  O 2  CO 2  H 2 O  ATP Lungs Fig 6.2 Breathing and Respiration O2O2 CO 2

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Glucose molecules broken down to CO 2 Glucose loses electrons and hydrogen  Oxidation Oxygen gains electrons and hydrogen  Reduction Cells tap energy from electrons Cells bank energy in ATP C 6 H 12 O 6 6 O 2 6 CO 2 6 H 2 O (Energy) ATP Glucose + ++ Loss of hydrogen atoms (oxidation) Gain of hydrogen atoms (reduction) Cellular Aerobic Respiration

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Oxidation - Enzyme removes electrons from substrate Reduction - Electrons in Hydrogen Transferred to NAD + Figure 6.5B O H H O 2H Reduction Dehydrogenase Enzyme (carries 2 electrons) NAD  2H 2H  2e  NADH HH Oxidation Transferring Energy in the cell

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings AEROBIC CELLULAR RESPIRATION Stages Glycolysis Chemical Grooming of Pyruvate Citric acid cycle Oxidative phosphorylation C 6 H 12 O 6 6 O 2 6 CO 2 6 H 2 O ATP + ++

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 2 NAD  2 NADH 2 H  1 Glucose 2 Pyruvate ATP 2 2 P 2 ADP + + Figure 6.7A Cellular Respiration Stage 1: Glycolysis Occurs in the cytoplasm Breaks down glucose into pyruvate Reduces coenzyme NAD + Produces a small amount of ATP

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Major steps in glycolysis 1. Preparatory phase: 2 ATP energize glucose ATP Glucose PREPARATORY PHASE ADP Step Glucose-6-phosphate Fructose-6-phosphate P P Fructose-1,6- bisphosphate ATP ADP P P Steps – A fuel molecule is energized, using ATP. Step A six-carbon intermediate splits into two three-carbon intermediates Figure 6.7C Cellular Respiration: Glycolysis

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Pyruvate ATP ADP ATP ADP P ATP ADP P 2-Phosphoglycerate P H2OH2O H2OH2O Phosphoenolpyruvate (PEP) Steps – ATP and pyruvate are produced. P 3 -Phosphoglycerate P P Step A redox reaction generates NADH. P NADH+H  P P P PP P ENERGY PAYOFF PHASE Glyceraldehyde-3-phosphate (G3P) 1,3 -Diphosphoglycerate P NAD   2. Energy Payoff: NADH+H + is formed 3. Energy Payoff: ATP is formed 4. Pyruvate is formed Figure 6.7C Cellular Respiration: Glycolysis ATP NADH+H  Cleavage of 6C sugar Energy Payoff

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Glycolysis produces ATP by substrate-level phosphorylation Enzyme Adenosine Organic molecule (substrate) ADP ATP P P P P P Figure 6.7B Cellular Respiration: Glycolysis

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings CO 2 Pyruvate NAD  NADH  H  CoA Acetyl Coenzyme A Coenzyme A Figure 6.8 Pyruvate is oxidized: 1.Releases CO 2 2.Produces NADH and acetyl Coenzyme A 3.Acetyl CoA is transferred to the mitochondrion Cellular Respiration Stage 2: Chemical Grooming of Pyruvate

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Oxaloacetate CoA 2 carbons enter cycle Acetyl CoA Citrate NAD  CO 2 Alpha-ketoglutarate CO 2 ADP + P NAD  ATP Succinate FAD FADH 2 Malate NAD  NADH  H  Figure 6.9B NADH  H  Cellular Respiration Stage 3: Citric Acid Cycle NADH  H 

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 1.Completely oxidizes “glucose” to CO 2 2.Produces a small amount of ATP 3.Supplies electrons to last stage of cellular respiration by reducing Coenzymes FAD & NAD Stage 3: Citric Acid Cycle

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Mitochondrion Structure Outer Membrane Inner Membrane Cristae Matrix Intermembrane Space

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 1.Electron Flow occurs in mitochondrial membrane 2.Protons are transported across the inner mitochondrial membrane 3.ATP is synthesized by Chemiosmosis Intermembrane space Inner mitochondrial membrane Mitochondrial matrix NAD + FAD H2OH2O H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Electron Transport Chain. Figure 6.10 Stage 4: Oxidative Phosphorylation NADH FADH 2 e-e- e-e- H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ O H+H+ H2OH2O

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Stage 4: Oxidative Phosphorylation ATP Synthesis by Chemiosmosis ATP H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ Chemiosmosis by ATP synthase Electron Transport Chain ADP P H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 1.Electron Flow occurs in mitochondrial membrane 2.Protons are transported across the inner mitochondrial membrane 3.ATP is synthesized by Chemiosmosis Intermembrane space Inner mitochondrial membrane Mitochondrial matrix Protein complex Electron carrier NAD + FAD H2OH2O ATP synthase H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ ATP ADP P H+H+ O2O2 Electron Transport Chain Chemiosmosis. OXIDATIVE PHOSPHORYLATION Figure 6.10 Stage 4: Oxidative Phosphorylation NADH FADH 2 e-e- e-e- e-e- H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings 1.Occurs in the mitochondria 2.Uses the energy released by electrons to pump H + across a membrane 3.Harnesses the energy of the H + gradient through chemiosmosis, producing ATP Stage 4: Oxidative Phosphorylation

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Oxidative Phosphorylation Connection Certain poisons interrupt oxidative phosphorylation Rotenone blocks the movement of electrons Oligomycin blocks H + flow through ATP synthase DNP allows H + to leak through the membrane H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ O2O2 H2OH2O P ATP NADHNAD + FADH 2 FAD Rotenone Cyanide, carbon monoxide Oligomycin DNP ATP Synthase  2 ADP  Electron Transport Chain Chemiosmosis 1 2 Figure 6.11 Genus: Derris Young Man Dies after Using a Diet Pill containing Dinitrophenol (DNP) oligomycin from the fungus Streptomyces

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings NADH+H + Cytoplasm Mitochondrion GLYCOLYSIS Glucose Pyruvate by substrate-level phosphorylation by oxidative phosphorylation OXIDATIVE PHOSPHORYLATION Acetyl CoA CITRIC ACID CYCLE About 38 ATP for each glucose FADH 2 Figure 6.12 Summary: Aerobic Cellular Respiration NADH+H + 2 ATP 34 ATP 2 ATP

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Fermentation = an anaerobic alternative to cellular respiration Uses glycolysis alone to produce small amounts of ATP Types of fermentation 1. Lactic acid fermentation 2. Alcoholic fermentation Anaerobic Cellular Respiration

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings NADH is oxidized to NAD + Pyruvate is reduced to lactate Lactate NAD  NADH NAD  ATP ADP  Pyruvate GLYCOLYSIS P Glucose Figure 6.13A Lactic Acid Fermentation

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings NADH is oxidized to NAD + Pyruvate is converted to CO 2 and ethanol NAD  NADH NAD  GLYCOLYSIS ADP  P ATP Glucose Pyruvate CO 2 Ethanol Figure 6.13B Alcohol Fermentation

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Carbohydrates, fats, and proteins converted to molecules entering –Glycolysis or citric acid cycle OXIDATIVE PHOSPHORYLATION Food, such as peanuts Carbohydrates Fats Proteins Sugars Glycerol Fatty acids Amino acids Amino groups GlucoseG3P Pyruvate Acetyl CoA CITRIC ACID CYCLE ATP GLYCOLYSIS Figure 6.14 Fuels for Respiration

Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Fuel for respiration comes from photosynthesis All organisms –Respire Plants, but not animals –Respire and Photosynthesize Figure 6.16

End Respiration