Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? -Consumption of food & oxygen to produce CO 2, water & energy -C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (ATP + heat) Chapter 9: Cellular Respiration: Harvesting Chemical Energy Light energy ECOSYSTEM CO 2 + H 2 O Photosynthesis in chloroplasts Cellular respiration in mitochondria Organic molecules + O 2 ATP powers most cellular work Heat energy

1.Why is respiration important? -Consumption of food & oxygen to produce CO 2, water & energy -C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (ATP + heat) -Exergonic releases -686 kcal/mol -All foods can be metabolized as fuel (carbs, proteins, fats,) Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? 2.What are redox rxns? -Reduction & oxidation -LEO says GER -Loss of Electrons – Oxidation : Gain of Electrons – Reduction - ┌----oxidation-----┐ -C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (ATP + heat) - └----reduction----┘ Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? -Glycolysis -Citric Acid Cycle (Krebs Cycle) -Oxidative Phosphorylation -Electron Transport Chain (ETC) -Chemiosmosis Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Electrons carried via NADH Glycolysis GlucosePyruvate ATP Substrate-level phosphorylation Electrons carried via NADH and FADH 2 Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis ATP Substrate-level phosphorylation Oxidative phosphorylation Mitochondrion

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? -Glucose is split in the cytosol -10 steps -NO oxygen needed Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Glycolysis Citric acid cycle Oxidative phosphorylation ATP 2 ATP 4 ATP used formed Glucose 2 ATP + 2 P 4 ADP + 4 P 2 NAD e H + 2 NADH + 2 H + 2 Pyruvate + 2 H 2 O Energy investment phase Energy payoff phase Glucose 2 Pyruvate + 2 H 2 O 4 ATP formed – 2 ATP used 2 ATP 2 NAD e – + 4 H + 2 NADH + 2 H +

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made in glycolysis? - Substrate-level phosphorylation – ATP produced from the transfer of a phosphate group from a substrate to ADP Chapter 9: Cellular Respiration: Harvesting Chemical Energy Enzyme ATP ADP Product Substrate P +

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? -NAD+ - nicotinamide adenine dinucleotide -Coenzyme -Accepts 2 e - and a H + Chapter 9: Cellular Respiration: Harvesting Chemical Energy

NAD + H O O OO–O– O O O–O– O O O P P CH 2 HO OH H H HOOH HO H H N+N+ C NH 2 H N H N N Nicotinamide (oxidized form) NH 2 + 2[H] (from food) Dehydrogenase Reduction of NAD + Oxidation of NADH 2 e – + 2 H + 2 e – + H + NADH O H H N C + Nicotinamide (reduced form) N H+H+ H+H+ Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? -Active transport across double membrane -3 step process Chapter 9: Cellular Respiration: Harvesting Chemical Energy

CYTOSOLMITOCHONDRION NADH + H + NAD CO 2 Coenzyme A Pyruvate Acetyl CoA S CoA C CH 3 O Transport protein O–O– O O C C CH 3 Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? -Mitochondrial matrix -8 steps -Spins 2X per glucose (1X for each pyruvate) Chapter 9: Cellular Respiration: Harvesting Chemical Energy

NAD + ATP 2 CO 2 3 NAD + 3 NADH + 3 H + ADP + P i FAD FADH 2 Citric acid cycle CoA Acetyl CoA NADH + H + CoA CO 2 Pyruvate (from glycolysis, 2 molecules per glucose) ATP Glycolysis Citric acid cycle Oxidative phosphorylation Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? 9.How many ATP so far? -4 total, 2 from glycolysis & 2 from Krebs Cycle -ALL from substrate-level phosphorylation Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? 9.How many ATP so far? 10.How many electron carriers so far? - 10 NADH - 2 FADH 2 Chapter 9: Cellular Respiration: Harvesting Chemical Energy

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? 9.How many ATP so far? 10.How many electron carriers so far? 11.What happens during electron transport? - redox rxns in inner mitochondrial membrane - electrons flow from electron carriers to electronegative O 2 - electron carriers “break the fall” 12. Why do electrons NEED to “break the fall?” Chapter 9: Cellular Respiration: Harvesting Chemical Energy

H / 2 O 2 2 H 1 / 2 O 2 (from food via NADH) 2 H e – 2 H + 2 e – H2OH2O 1 / 2 O 2 Controlled release of energy for synthesis of ATP ATP Electron transport chain Free energy, G (b) Cellular respiration (a) Uncontrolled reaction Free energy, G H2OH2O Explosive release of heat and light energy + Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Glycolysis Citirc acid cycle Oxidative phosphorylation ATP H2OH2O O2O2 NADH FADH 2 FMN FeS O FAD Cyt b Cyt c 1 Cyt c Cyt a Cyt a 3 2 H  2 I II III IV Multiprotein complexes Free energy (G) relative to O 2 (kcl/mol) Figure 9.13 Free-energy change during electron transport

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? 9.How many ATP so far? 10.How many electron carriers so far? 11.What happens during electron transport? 12.Why do electrons NEED to “break the fall?” 13.How is ATP made during chemiosmosis? Chapter 9: Cellular Respiration: Harvesting Chemical Energy

MITOCHONDRIAL MATRIX INTERMEMBRANE SPACE H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ H+H+ P i + ADP ATP A rotor within the membrane spins clockwise when H + flows past it down the H + gradient. A stator anchored in the membrane holds the knob stationary. A rod (or “stalk”) extending into the knob also spins, activating catalytic sites in the knob. Three catalytic sites in the stationary knob join inorganic Phosphate to ADP to make ATP. Figure 9.14 ATP synthase, a molecular mill

Oxidative phosphorylation electron transport and chemiosmosis Glycolysis ATP Inner Mitochondrial membrane H+H+ H+H+ H+H+ H+H+ H+H+ ATP P i Protein complex of electron carners Cyt c I II III IV (Carrying electrons from food) NADH + FADH 2 NAD + FAD + 2 H / 2 O 2 H2OH2O ADP + Electron transport chain Electron transport and pumping of protons (H + ), which create an H + gradient across the membrane Chemiosmosis ATP synthesis powered by the flow Of H + back across the membrane ATP synthase Q Oxidative phosphorylation Intermembrane space Inner mitochondrial membrane Mitochondrial matrix Citirc acid cycle Figure 9.15 Chemiosmosis couples the electron transport chain to ATP synthesis 1 NADH = 3 ATP 1 FADH 2 = 2 ATP

Electron shuttles span membrane CYTOSOL 2 NADH 2 FADH 2 2 NADH 6 NADH 2 FADH 2 2 NADH Glycolysis Glucose 2 Pyruvate 2 Acetyl CoA Citric acid cycle Oxidative phosphorylation: electron transport and chemiosmosis MITOCHONDRION by substrate-level phosphorylation by substrate-level phosphorylation by oxidative phosphorylation, depending on which shuttle transports electrons from NADH in cytosol Maximum per glucose: About 36 or 38 ATP + 2 ATP + about 32 or 34 ATP or Figure 9.16 ATP yield per molecule of glucose at each stage of cellular respiration

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? 9.How many ATP so far? 10.How many electron carriers so far? 11.What happens during electron transport? 12.Why do electrons NEED to “break the fall?” 13.How is ATP made during chemiosmosis? 14.What happens when there is no O 2 ? - anaerobic respiration (fermentation) Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Glucose CYTOSOL Pyruvate No O 2 present Fermentation O 2 present Cellular respiration Ethanol or lactate Acetyl CoA MITOCHONDRION Citric acid cycle Figure 9.18 Pyruvate as a key juncture in catabolism

2 ADP + 2 P iP i 2 ATP Glycolysis Glucose 2 NAD + 2 NADH 2 Pyruvate 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation 2 ADP + 2 P i 2 ATP Glycolysis Glucose 2 NAD + 2 NADH 2 Lactate (b) Lactic acid fermentation H H OH CH 3 C O – O C CO CH 3 H CO O–O– CO CO O C O C OHH CH 3 CO Pyruvate +2 H + Figure 9.17 Fermentation

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? 9.How many ATP so far? 10.How many electron carriers so far? 11.What happens during electron transport? 12.Why do electrons NEED to “break the fall?” 13.How is ATP made during chemiosmosis? 14.What happens when there is no O 2 ? 15.How do the other foods we eat get catabolized? Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Amino acids Sugars Glycerol Fatty acids Glycolysis Glucose Glyceraldehyde-3- P Pyruvate Acetyl CoA NH 3 Citric acid cycle Oxidative phosphorylation Fats Proteins Carbohydrates Figure 9.19 The catabolism of various molecules from food

1.Why is respiration important? 2.What are redox rxns? 3.What are the 3 main steps of respiration? 4.What happens during glycolysis? 5.How is the ATP made? 6.How do electrons get from glucose to O 2 ? 7.How does pyruvate get into the mitochondria for the Krebs Cycle? 8.What happens during the Citric Acid Cycle? 9.How many ATP so far? 10.How many electron carriers so far? 11.What happens during electron transport? 12.Why do electrons NEED to “break the fall?” 13.How is ATP made during chemiosmosis? 14.What happens when there is no O 2 ? 15.How do the other foods we eat get catabolized? 16.How is cellular respiration controlled? Chapter 9: Cellular Respiration: Harvesting Chemical Energy

Glucose Glycolysis Fructose-6-phosphate Phosphofructokinase Fructose-1,6-bisphosphate Inhibits Pyruvate ATP Acetyl CoA Citric acid cycle Citrate Oxidative phosphorylation Stimulates AMP + – – Figure 9.20 The control of cellular respiration

Respiration Pictographs Today you will construct pictographs on the topics listed below. Your groups will create this pictograph using a fun & creative example to tell the story of the process. Your pictograph will include where each process occurs, who the main players are, and what their role is. Then EACH of you will write a paragraph indicating how each of your symbols from the pictograph represents the biology of the process. You will present these pictographs tomorrow. Topics: Glycolysis (Figure 9.8) Citric Acid Cycle (Figure 9.11) Oxidative Phosphorylation: Electron Transport (Fig & 9.15) Oxidative Phosphorylation: Chemiosmosis (Figure 9.14 & 9.15) Anaerobic respiration (Figure 9.17)