1. Cellular Respiration Part 1
Harvesting Chemical Energy from Glucose

2. Releasing Energy From Glucose
Energy Released
Glucose (6C)
Energy Released
ATP
Glycolysis
e- Carriers e-
2 X Pyruvate (3C)
Cytoplasm
O2 present
2 CO2
Mitochondrion
e- Carriers
2 X Acetyl-CoA (2C)
ATP
Electron Transport Chain
Citric Acid Cycle
4 CO2
H2O
e- Carriers
2 H+
ATP
½ O2

3. Redox Reactions
Reduction: Gain of one or more electrons or hydrogen atoms
Oxidation: Loss of one or more electrons or hydrogen atoms
Electron carrier NAD+ accepts two electrons and one proton to become NADH

4. 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

5. Overview of Glycolysis
Glucose (6C) C
Set of 10 reactions
2 ATP
4 ATP
Net gain of 2 ATP
2 NAD+
2 NADH
2 X Pyruvate (3C) C
Occurs in cytoplasm under anaerobic conditions Gluconeogenesis can convert pyruvate glucose

6. Energy Investment Reactions of Glycolysis Step 1
Reaction Type
Phosphorylation
Reactants
Glucose ATP
Enzyme
Hexokinase
Products
Glucose 6-phosphate ADP
Energy Carriers
- 1 ATP

7. Energy Investment Reactions of Glycolysis Step 2
Reaction Type
Isomerization
Reactant
Glucose 6-phosphate
Enzyme
Phosphoglucoisomerase
Product
Fructose 6-phosphate

8. Energy Investment Reactions of Glycolysis Step 3
Reaction Type
Phosphorylation
Reactant
Fructose 6-phosphate ATP
Enzyme
Phosphofructokinase
Product
Fructose-1,6-bisphosphate ADP
Energy Carriers
-1 ATP

9. Energy Investment Reactions of Glycolysis--Step 4
Reaction Type
Cleavage
Reactant
Fructose-1,6-bisphosphate
Enzyme
Aldolase
Products
Dihydroxyacetone phosphate Glyceraldehyde 3-phosphate

10. Energy Investment Reactions of Glycolysis Step 5
Reaction Type
Isomerization
Reactant
Dihydroxyacetone Phosphate
Enzyme
Isomerase
Product
Glyceraldehyde 3-phosphate

11. Energy-Harvesting Reactions of Glycolysis Step 6
1. NAD+
2. G3P
3. BPG
4. NADH
A. Which undergoes oxidation?
B. Which undergoes reduction?
Energy-Harvesting Reactions of Glycolysis Step 6
Reaction Type
Redox + Phosphorylation
Reactants
2 X Glyceraldehyde 3-Phosphate 2 NAD+, 2 Pi
Enzyme
Triose phosphate dehydrogenase
Products
2 X 1,3-Bisphosphoglycerate
Energy Carriers
2 NADH + 2 H+

12. Energy-Harvesting Reactions of Glycolysis Step 7
Reaction Type
Phosphorylation
Reactants
2 X 1,3-Bisphosphoglycerate 2 ADP
Enzyme
Phosphoglycerokinase
Products
2 X 3-Phosphoglycerate
Energy Carriers
+2 ATP Substrate Level Phosphorylation

13. Energy-Harvesting Reactions of Glycolysis Step 8
Reaction Type
Isomerization
Reactants
2 X 3-Phosphoglycerate
Enzyme
Phosphoglyceromutase
Products
2 X 2-Phosphoglycerate

14. Energy-Harvesting Reactions of Glycolysis Step 9
Reaction Type
Dehydration
Reactants
2 X 2-Phosphoglycerate
Enzyme
Enolase
Products
2 Phosphoenolpyruvate 2 H2O

15. Energy-Harvesting Reactions of Glycolysis Step 10
Reaction Type
Phosphorylation
Reactants
2 Phosphoenolpyruvate 2 ADP
Enzyme
Pyruvate kinase
Products
2 Pyruvate
Energy Carriers
+2 ATP Substrate Level Phosphorylation

16. Pyruvate Oxidation 2 X Reaction Type Redox Reactants
1. NAD+
2. Acetyl-CoA
3. Pyruvate
4. NADH
A. Which molecule is an oxidizing agent?
B. Which is a reducing agent?
Pyruvate Oxidation
2 X 2 +2
Reaction Type
Redox
Reactants
2 Pyruvate 2 Coenzyme A (CoA) 2 NAD+
Enzyme
Dehydrogenase
Products
2 Acetyl CoA 2 CO2
Energy Carriers
2 NADH + 2H+
Occurs in the Mitochondrial Matrix Not Reversible, Cannot convert 2C3C for pyruvate  glucose pathway

17. Overview of the Citric Acid Cycle
CoA C
Acetyl-CoA (2C)
2 X
Citric Acid Cycle Set of 8 reactions
2 ADP
2 ATP
4 CO2 C
6 NAD+
6 NADH
2 FAD
2 FADH2
Electron Transport Chain

18. Citric Acid Cycle Step 1 Reaction Type Synthesis Reactants
2 Acetyl-CoA 2 Oxaloacetate
Enzyme
Citrate synthase
Products
2 Citrate

19. Citric Acid Cycle Step 2 Reaction Type Isomerization Reactants
2 Citrate
Enzyme
Aconitase
Products
2 Isocitrate

20. Citric Acid Cycle Step 3 Reaction Type Redox + Decarboxylation
Reactants
2 Isocitrate, 2 NAD+
Enzyme
Dehydrogenase
Products
2 Alpha-Ketoglutarate 2 CO2
Energy Carriers
2 NADH + 2H+

21. Citric Acid Cycle Step 4 Reaction Type Redox + Decarboxylation
Reactants
2 Alpha-Ketoglutarate, 2 CoA 2 NAD+
Enzyme
Dehydrogenase
Products
2 Succinyl-CoA, 2 CO2
Energy Carriers
2 NADH + 2 H+

22. Citric Acid Cycle Step 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

23. Citric Acid Cycle Step 6 Reaction Type Redox Reactant 2 Succinate
1. FAD
2. Fumarate
3. Succinate
4. FADH2
A. Which undergoes oxidation?
B. Which undergoes reduction?
Citric Acid Cycle Step 6
Reaction Type
Redox
Reactant
2 Succinate
Enzyme
Dehydrogenase
Products
2 Fumarate
Energy Carriers
2 FADH2

24. Citric Acid Cycle Step 7 Reaction Type Hydration Reactants
2 Fumarate, 2 H2O
Enzyme
Fumarase
Products
2 Malate

25. Citric Acid Cycle Step 8 Reaction Type Redox Reactants
2 Malate, 2 NAD+
Enzyme
Dehydrogenase
Products
2 Oxaloacetate
Energy Carriers
2 NADH + 2 H+

26. Free Energy Change for Glucose Oxidation

27. Energy Harvested from Glucose
(Cytoplasm)
Glucose
2 ATP
Net Gain
Glycolysis
4 ATP
2 ATP
2 Pyruvates
(Mitochondrial Matrix)
2 NADH
2 CO2
2 NADH
Citric Acid Cycle
6 NADH
4 CO2
2 FADH2
2 ATP
(Inner Membrane)
Water
Electron Transport System
32 ATP
Oxygen

28. Applying Your Knowledge
Cytoplasm
Mitochondrion
Both Cytoplasm and Mitochondrion
Neither the Cytoplasm nor Mitochondrion
Where is the Citric Acid cycle located?
Where does glycolysis occur?
Where is CO2 produced?
Where is the electron transport chain located?