Cellular Respiration

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Cellular Respiration
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Cellular Respiration

• A catabolic, exergonic, oxygen (O2) requiring
  process that uses energy extracted from
  macromolecules (glucose) to produce energy (ATP)
  and water (H2O).
• C6H12O6 6O2 ? 6CO2 6H2O energy

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Question

• In what kinds organisms does cellular respiration
  take place?

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Plants and Animals

• Plants - Autotrophs self-producers.
• Animals - Heterotrophs consumers.

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Mitochondria

• Organelle where cellular respiration takes place.

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Breakdown of Cellular Respiration

• Three main parts (reactions).
• 1. Glycolysis (splitting of sugar)
• a. cytosol, just outside of mitochondria.
• .

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Breakdown of Cellular Respiration

• 2. Krebs Cycle (Citric Acid Cycle)
• a. mitochondrial matrix
• 3. Electron Transport Chain (ETC
• a.. inner mitochondrial membrane.

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1. Glycolysis

• Occurs in the cytosol just outside of
  mitochondria.
• Two phases
• A. Energy investment phase
• a. Preparatory phase
• B. Energy yielding phase
• a. Energy payoff phase

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1. Glycolysis

• A. Energy Investment Phase

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1. Glycolysis

• B. Energy Yielding Phase

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1. Glycolysis

• Total Net Yield
• 2 - 3C-Pyruvate (PYR)
• 2 - ATP
• 2 - NADH

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2. Krebs Cycle (Citric Acid Cycle)

• Location mitochondrial matrix.
• Acetyl CoA (2C) bonds to Oxalacetic acid (4C -
  OAA) to make Citrate (6C).
• It takes 2 turns of the krebs cycle to oxidize 1
  glucose molecule.

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2. Krebs Cycle (Citric Acid Cycle)
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2. Krebs Cycle (Citric Acid Cycle)
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2. Krebs Cycle (Citric Acid Cycle)

• Total net yield (2 turns of krebs cycle)
• 1. 2 - ATP (substrate-level phosphorylation)
• 2. 6 - NADH
• 3. 2 - FADH2
• 4. 4 - CO2

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3. Electron Transport Chain (ETC) and Oxidative
Phosphorylation (Chemiosmosis)

• Location inner mitochondrial membrane.
• Uses ETC and ATP Synthase (enzyme) to make ATP.
• ETC pumps H (protons) across innermembrane
  (lowers pH in innermembrane space).

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3. Electron Transport Chain (ETC) and Oxidative
Phosphorylation (Chemiosmosis)

• The H then moves via diffusion through ATP
  Synthase to make ATP.
• All NADH and FADH2 converted to ATP during this
  stage of cellular respiration.
• Each NADH converts to 3 ATP.
• Each FADH2 converts to 2 ATP (enters the ETC at a
  lower level than NADH).

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TOTAL ATP YIELD

• 1. 04 ATP glycolysis and krebs cycle
• 2. 34 ATP - ETC
• 38 ATP - TOTAL YIELD

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Maximum ATP Yield for Cellular Respiration
(Eukaryotes)
36 ATP (maximum per glucose)
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Fermentation

• Occurs in cytosol when NO Oxygen is present
  (called anaerobic).
• Remember glycolysis is part of fermentation.
• Two Types
• 1. Alcohol Fermentation
• 2. Lactic Acid Fermentation

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Alcohol Fermentation

• Plants and Fungi ? beer and wine

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Lactic Acid Fermentation

• Animals (pain in muscle after a workout).

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Lactic Acid Fermentation

• End Products Lactic acid fermentation
• 2 - ATP
• 2 - Lactic Acid molecules

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Alcohol Fermentation

• End Products Alcohol fermentation
• 2 - ATP
• 2 - CO2
• 2 molecules of ethanol

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Question

• In addition to glucose, what other various food
  molecules are use in Cellular Respiration?

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Catabolism of VariousFood Molecules

• Other organic molecules used for fuel.
• 1. Carbohydrates polysaccharides
• 2. Fats glycerols and fatty acids
• 3. Proteins amino acids