Lesson 9 Energy from Organic Molecules II; Notes and Diagram Annotations PDF

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Includes diagram annotations and annotated notes...

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9.1 Summarize the energy yield after each stage of aerobic respiration. ● ●

Steps: Glycolysis, Pyruvate oxidation, the Krebs cycle 1 glucose molecule oxidized to 6 CO2, 4 ATP, [10 NADH, 2 FADH2 (proceed to electron transport chain)] ○

Electron transport chain → harvested to drive synthesis of ATP through oxidative phosphorylation

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Electron transport Chain: allows for stepwise extraction of energy as electrons are passed from one component to next ■ Energy depleted electrons transferred to final acceptor ■ Electron potential energy converted to ATP ■

Series of membrane-bound protein complexes and lipid soluble electron carriers → in mitochondrial inner membrane

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Has three transmembrane enzyme complexes that harvest some energy from electrons and pass lower energy electrons onward Complexes use energy harvested from electrons to pump protons from matrix to intermembrane space

9.2. Diagram the flow of electrons through the electron transport chain. ●

Flow of electrons in mitochondrial complex:

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NADH delivers electrons to NADH dehydrogenase → extracts energy to power protons movement across inner membrane → passes electrons to lipid soluble carrier (Q) → passes electrons to BC1 complex → extracts energy from electrons and pumps protons across inner membrane → transfers electrons to Cytochrome C → carries proteins to Cytochrome oxidase complex → harvests energy to pump protons → catalyzes reduction of molecular oxygen → produces water

9.3. Describe how chemiosmosis couples electron transport to ATP synthesis during oxidative phosphorylation. ●

Chemiosmosis: process by which energy in gradient is converted to chemical energy (ATP) ○

Proton gradient represents potential energy → creates proton motor force that drives synthesis of ATP

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ATP synthase uses energy released by movement of protons to synthesize ATP from ADP + Pi Movement of 4 H+ through ATP synthase powers synthesis of 1 ATP molecule

9.4. Distinguish aerobic respiration, anaerobic respiration and fermentation. ●

Anaerobic respiration: respiration without oxygen ○ Inorganic molecules (not O2) used as final electron acceptor ○ Many prokaryotes use sulfur, carbon dioxide, or even inorganic metals ○

Not as electronegative → free energy released and ATP produced is less than with O2

Ex: methanogens ■ CO2 reduced to CH4 ■ Found in diverse environments Fermentation: get energy without oxygen ○ Glycolysis is only source of ATP ○ Use of organic molecule as final electron acceptor ○ Reduces organic molecules in order to regenerate NAD+ ○ Ex: ethanol fermentation in yeast ■ CO2, ethanol, and NAD+ produced ○ Ex: Lactic acid fermentation ■ Occurs in animals cells (muscles) ■ Electrons transferred from NADH to pyruvate to produce lactic acid ■ Allows glycolysis and some ATP production to continue ○

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9.5. Describe how proteins and fats are catabolized to produce energy.

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Catabolism of proteins: ○

Broken down into amino acid → undergo deamination to remove amino group → remainder amino acid converted to molecule that enters glycolysis or Krebs cycle

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Catabolism of fats: ○

Fats broken down into fatty acids → converted to acetyl groups by beta oxidation → acetyl group combined with Coenzyme A to form acetyl-CoA → acetyl CoA enters Kreb Cycle

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Respiration of 6 carbon fatty acid yields 20% more energy than 6 carbon glucose...