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DR. MICHAEL C. POTTER PAUL VI CATHOLIC HIGH
SCHOOL 2006
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• GLUCOSE CATABOLISM
• STAGE I GLYCOLYSIS
• STAGE II PYRUVATE OXIDATION
• STAGE III KREBS CYCLE
• STAGE IV ELECTRON TRANSPORT

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• GLYCOLYSIS A process that occurs
• in the cytoplasm of every living cell
• 1. Glucose Priming This changes
• glucose into a molecule that can be
• cleaved.
• Requires 2 molecules of ATP
• Phosphofructokinase commits
• glucose to glycolysis

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• GLYCOLYSIS
• 2. Splitting Rearrangement
• Six carbon compound splits
• to (2) 3 carbon cmpds.
• Fructose 1,6, Diphosphate into
• (2) Glyceraldehyde 3 PO4
• Substrate Level Phosphorylation
• Making ATP (4 molecules/glucose)

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GLYCOLYSIS 3. Oxidation Removal of electrons
(energy) capturing in NADH from NAD.
4. ATP Generation 4 reactions that convert
G-3-PO4 to Pyruvate Generates 2 ATP per
Pyruvate
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GLYCOLYSIS RESULTS IN Glucose ? 2 molecules
Pyruvate 2 molecules ADP ? ATP for
each molecule of pyruvate 2 molecules NAD ?
NADH from oxidation of glyceraldehyde-3-PO4
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B. Oxidation of Pyruvate Occurs in
mitochondrion 1. Aerobic conditions Pyruvate
OXIDIZED to Acetyl CoA 2. Anaerobic
conditions result in FERMENTATION REACTIONS
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FERMENTATION REACTIONS 1.Lactic Acid
Fermentation Pyruvate REDUCED to Lactate No
CO2 removal NADH ? NAD 2. Alcohol
Fermentation Fungal (Yeast) Cells Pyruvate
REDUCED to Alcohol CO2 Removed NADH ? NAD
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C. KREBS CYCLE 1. Priming
Reactions Prepares the molecule for energy
extraction Acetyl CoA (2C) joins oxaloacetate
(4C) to form Citrate (6C) Citrate isomerizes
to Isocitrate
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C. KREBS CYCLE 2. Energy Extraction-
oxidation reactions disassembling the
molecule Decarboxylation Reactions
Reduction NAD? NADH Reduction FAD ?
FADH2 Regeneration oxaloacetate
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D. ELECTRON TRANSPORT System of REDOX
reactions Series of membrane electron
carriers Ubiquinone (quinone
molecule) Cytochromes (contain Fe) OXYGEN is
final electron acceptor Water is final product
(two H) attach to oxygen
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D. ELECTRON TRANSPORT The movement of electrons
down the concentration gradient to O2 as
the final acceptor releases protons (H) to
the intermembrane space Protons move thru
ATP synthase making ATP from ADP (oxidative
phosphorylation)
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ENERGY (ATP) YIELD per GLUCOSE Glycolysis 2ATP
by substrate level phosphorylation Oxidation
Pyruvate 2 NADH (3 ATP per) Krebs Cycle 6
NADH (3 ATP per) 2 FADH2 (1-2 ATP per) 2
ATP via GTP Electron Transport 32 ATP
oxidative phosphorylation
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Alternate Sources for Metabolism Glycolytic
pathway thru ETS is final common pathway
Other macromolecules can be utilized Lipids
via ß-oxidation Proteins via deamination
(NH3) Nucleic Acids via deamination
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Control of Glucose Catabolism Feedback
inhibition Phosphofructokinase inhibited by
ATP levels Citrate levels Phosphofructokinase
stimulated by ADP levels AMP levels
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There is a mutualistic symbiotic relationship
between the products of glycolysis and the
requirements for photosynthesis. This is an
interrelationship between the cells mitochondria
and chloroplast.
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