101 StructureFunction of the Organelles II'EnergeticsRespiration

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10-1 Structure/Function of the Organelles
II. Energetics/Respiration
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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Biochemical reactions which occur in the cell
• Grouped into metabolic pathways
• Sequence
• Catalyzed by enzymes
• Product of one Substrate for next

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Each pathway confined to one compartment
• Cytosol / Mitochondrion
• Enzymes of a pathway physically linked

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Compounds formed in each step metabolic
  intermediates
• Formation of the end product

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Pathways are interconnected
• Specific points
• Pathways activated depending on requirements of
  the cell

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Our focus The Transfer and Utilization of
  Chemical Energy

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Catabolic pathways
• Disassembly
• Simpler products
• Two functions

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Catabolic pathways Two functions
• Provide raw materials
• Provide chemical energy

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Catabolic pathways
• Energy released stored in two forms
• High energy phosphates ATP
• High energy electrons - NADPH

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Anabolic pathways
• Synthesis of complex compounds
• Energy demanding

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Metabolism
• Major categories of metabolic pathways in energy
  transfer and utilization

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Oxidation/Reduction
• Atom looses electrons oxidized
• Atom gains electrons reduced
• Focus on C- compounds

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Oxidation/Reduction
• C-H bond
• C-O bond
• C-N bond
• Consider CH4 fully reduced
• CO2 fully oxidized

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Oxidation/Reduction
• Degree of reduction
• A measure of its potential to perform work
• CHO rich in energy H-C-OH structure
• Fats more energy Strings of H-C-H

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Oxidation/Reduction
• Consider glucose complete oxidation
• C6H12O6 6O2 6CO2 6H2O
• DG0 -686 kcal/mol

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Oxidation/Reduction
• Consider ATP production from ADP
• ADP Pi ATP H2O
• G0 7.3 kcal/mol

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Two stages in catabolism of glucose
• Glycolysis in cytosol
• Forms the intermediate pyruvate
• Tricarboxylic Acid Cycle (TCA cycle) in
  mitochondria
• Removal of high energy electrons

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Glycolysis

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• Glycolysis

http//www.johnkyrk.com/glycolysis.html
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Transfer and Utilization of Chemical Energy for
Cellular Activities

• ATP Processes of formation
• Two different ways
• Overall reaction oxidation of an aldehyde to a
  carboxlyic acid
• Two steps two different enzymes
• 1. The first requires nicotinamide adenine
  dinucleotide - NAD
• Accepting and donating electrons
• Oxidized form NAD
• Reduced form NADH
• NADH a high energy compound

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• ATP Processes of formation
• Two different ways
• 1. Electrons transferred through a series of
  membrane-embedded electron carriers
• Electron transport chain
• Move from high to lower free energy states
• Process oxidative phosphorylation

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Transfer and Utilization of Chemical Energy for
Cellular Activities

• ATP Processes of formation
• Two different ways
• 2. Reaction catalyzed by phosphoglycerate kinase
• Direct route of ATP formation
• Substrate-level phosphorylation