Cellular Respiration Part 1

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Cellular RespirationPart 1

• Harvesting Chemical Energy from Glucose

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Releasing Energy From Glucose
EnergyReleased
Glucose (6C)
2 X Pyruvate (3C)
Cytoplasm
Mitochondrion
2 X Acetyl-CoA (2C)
H2O
½ O2
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Redox Reactions

• Reduction Gain of one or more electrons or
  hydrogen atoms
• Oxidation Loss of one or more electrons or
  hydrogen atoms

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Energy Yield of Glucose Oxidation

• C6H12O6 6O2? 6CO2 6H2O energy
• 40 of released energy captured in ATP
• Involves two electron carriers
• NAD 2H 2 electrons ? NADH H
• FAD 2H 2 electrons ? FADH2
• Electrons donated to Electron Transport Chain to
  produce ATP

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Overview of Glycolysis
Net gain of 2 ATP
Occurs in cytoplasm under anaerobic
conditionsGluconeogenesis can convert pyruvate
?glucose
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Energy Investment Reactions of Glycolysis Step 1
Reaction Type Phosphorylation
Reactants Glucose ATP
Enzyme Hexokinase
Products Glucose 6-phosphateADP
Energy Carriers - 1 ATP
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Energy Investment Reactions of Glycolysis Step 2
Reaction Type Isomerization
Reactant Glucose 6-phosphate
Enzyme Phosphoglucoisomerase
Product Fructose 6-phosphate
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Energy Investment Reactions of Glycolysis Step 3
Reaction Type Phosphorylation
Reactant Fructose 6-phosphateATP
Enzyme Phosphofructokinase
Product Fructose-1,6-bisphosphateADP
Energy Carriers -1 ATP
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Energy Investment Reactions of Glycolysis--Step 4
Reaction Type Cleavage
Reactant Fructose-1,6-bisphosphate
Enzyme Aldolase
Products Dihydroxyacetone phosphateGlyceraldehyde 3-phosphate
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Energy Investment Reactions of Glycolysis Step 5
Reaction Type Isomerization
Reactant Dihydroxyacetone Phosphate
Enzyme Isomerase
Product Glyceraldehyde 3-phosphate
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Energy-Harvesting Reactions of Glycolysis Step 6
1. NAD 2. G3P 3. BPG
4. NADH A. Which undergoes oxidation? B.
Which undergoes reduction?
Reaction Type Redox Phosphorylation
Reactants 2 X Glyceraldehyde 3-Phosphate2 NAD, 2 Pi
Enzyme Triose phosphate dehydrogenase
Products 2 X 1,3-Bisphosphoglycerate
Energy Carriers 2 NADH 2 H
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Energy-Harvesting Reactions of Glycolysis Step 7
Reaction Type Phosphorylation
Reactants 2 X 1,3-Bisphosphoglycerate2 ADP
Enzyme Phosphoglycerokinase
Products 2 X 3-Phosphoglycerate
Energy Carriers 2 ATPSubstrate Level Phosphorylation
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Energy-Harvesting Reactions of Glycolysis Step 8
Reaction Type Isomerization
Reactants 2 X 3-Phosphoglycerate
Enzyme Phosphoglyceromutase
Products 2 X 2-Phosphoglycerate
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Energy-Harvesting Reactions of Glycolysis Step 9
Reaction Type Dehydration
Reactants 2 X 2-Phosphoglycerate
Enzyme Enolase
Products 2 Phosphoenolpyruvate2 H2O
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Energy-Harvesting Reactions of Glycolysis Step 10
Reaction Type Phosphorylation
Reactants 2 Phosphoenolpyruvate2 ADP
Enzyme Pyruvate kinase
Products 2 Pyruvate
Energy Carriers 2 ATPSubstrate Level Phosphorylation
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Pyruvate Oxidation
1. NAD 2. Acetyl-CoA 3.
Pyruvate 4. NADH A. Which molecule is an
oxidizing agent? B. Which is a reducing agent?
Reaction Type Redox
Reactants 2 Pyruvate2 Coenzyme A (CoA)2 NAD
Enzyme Dehydrogenase
Products 2 Acetyl CoA2 CO2
Energy Carriers 2 NADH 2H
Occurs in the Mitochondrial MatrixNot
Reversible, Cannot convert 2C?3C for pyruvate ?
glucose pathway
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Overview of the Citric Acid Cycle
Electron Transport Chain
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Citric Acid CycleStep 1
Reaction Type Synthesis
Reactants 2 Acetyl-CoA2 Oxaloacetate
Enzyme Citrate synthase
Products 2 Citrate
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Citric Acid CycleStep 2
Reaction Type Isomerization
Reactants 2 Citrate
Enzyme Aconitase
Products 2 Isocitrate
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Citric Acid CycleStep 3
Reaction Type Redox Decarboxylation
Reactants 2 Isocitrate, 2 NAD
Enzyme Dehydrogenase
Products 2 Alpha-Ketoglutarate2 CO2
Energy Carriers 2 NADH 2H
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Citric Acid CycleStep 4
Reaction Type Redox Decarboxylation
Reactants 2 Alpha-Ketoglutarate, 2 CoA2 NAD
Enzyme Dehydrogenase
Products 2 Succinyl-CoA, 2 CO2
Energy Carriers 2 NADH 2 H
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Citric Acid CycleStep 5
Reaction Type Redox Phosphorylation
Reactant 2 Succinyl-CoA, 2 ADP
Enzyme Synthase
Products 2 Succinate, 2 CoA
Energy Carriers 2 ATP, Substrate Level Phosphorylation
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Citric Acid CycleStep 6
1. FAD 2. Fumarate 3.
Succinate 4. FADH2 A. Which undergoes
oxidation? B. Which undergoes reduction?
Reaction Type Redox
Reactant 2 Succinate
Enzyme Dehydrogenase
Products 2 Fumarate
Energy Carriers 2 FADH2
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Citric Acid CycleStep 7
Reaction Type Hydration
Reactants 2 Fumarate, 2 H2O
Enzyme Fumarase
Products 2 Malate
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Citric Acid CycleStep 8
Reaction Type Redox
Reactants 2 Malate, 2 NAD
Enzyme Dehydrogenase
Products 2 Oxaloacetate
Energy Carriers 2 NADH 2 H
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Free Energy Change for Glucose Oxidation
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Energy Harvested from Glucose
Glucose
(Cytoplasm)
4 ATP
Glycolysis
2 ATP
2 Pyruvates
2 NADH
(MitochondrialMatrix)
2 CO2
2 NADH
Citric AcidCycle
6 NADH
4 CO2
2 FADH2
2 ATP
(InnerMembrane)
Water
Electron TransportSystem
32 ATP
Oxygen
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Applying Your Knowledge

1. Cytoplasm
2. Mitochondrion
3. Both Cytoplasm and Mitochondrion
4. Neither the Cytoplasm nor Mitochondrion

1. Where is the Citric Acid cycle located?
2. Where does glycolysis occur?
3. Where is CO2 produced?
4. Where is the electron transport chain located?