Chapter 9 Notes

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Chapter 9 Notes

• Cellular Respiration

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9-1 Chemical Pathways

• All living organisms need food to survive.
• Food provides living things with the chemical
  building blocks they need to grow and reproduce.

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9-1 Chemical Pathways

• 1 gram of glucose releases 3811 calories of heat
  energy
• Calorie (c) the amount of energy needed to raise
  the temperature of 1 gram of water 1 Celsius
  degree
• The calories on food labels (C) are kilocalories
  or 1000 calories

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9-1 Chemical Pathways

• Cells gradually release energy from glucose and
  other food compounds.
• Cellular respiration is the process that releases
  energy by breaking down food molecules in the
  presence of oxygen.
• - 3 parts glycolysis, the Krebs cycle, and the
  electron transport chain

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Electrons carried in NADH
Pyruvic acid
Electrons carried in NADH and FADH2
Glucose
Glycolysis
Krebs Cycle
Electron Transport Chain
Cytoplasm
Mitochondrion
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9-1 Chemical Pathways

• Equation for Cellular Respiration
• 6O2 C6H12O6 ? 6CO2 6 H2O Energy
• oxygenglucose ?carbonwaterenergy
• dioxide

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9-1 Chemical Pathways
Glucose
Krebs cycle
Electrontransport
Glycolysis
Alcohol or lactic acid
Fermentation (without oxygen)
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9-1 Chemical Pathways

• The first set of chemical reactions in cellular
  respiration is glycolysis.
• Glycolysis is the process in which one molecule
  of glucose is broken in half, producing two
  molecules of pyruvic acid, a 3-carbon compound

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9-1 Chemical Pathways

• Net results of glycolysis
• - 2 molecules of ATP are gained
• - 2 molecules of NADH are gained
• - 2 molecules of pyruvic acid (3C) are formed
  from 1 glucose molecule

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9-1 Chemical Pathways
4 ADP
2 ATP
2 ADP
4 ATP
Glucose
2 Pyruvic acid
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9-1 Chemical Pathways

• When oxygen is present in the cell, glycolysis is
  followed by the Krebs cycle.
• If there is no oxygen present, glycolysis is
  followed by fermentation.
• Fermentation releases energy from food molecules
  in the absence of oxygen

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9-1 Chemical Pathways

• Because fermentation does not require oxygen it
  is said to be anaerobic.
• The two main types of fermentation are alcoholic
  fermentation and lactic acid fermentation

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9-1 Chemical Pathways
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9-1 Chemical Pathways
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9-1 Chemical Pathways

• Alcoholic fermentation is used mainly by plants
  and yeasts
• - alcohol is the product
• Lactic acid fermentation occurs in muscle cells
  when the body cannot supply enough oxygen to the
  tissues
• - lactic acid is the product

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Section Quiz

• The raw materials required for cellular
  respiration are
• carbon dioxide and oxygen.
• glucose and water.
• glucose and oxygen.
• carbon dioxide and water.

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Section Quiz

• Glycolysis occurs in the
• mitochondria.
• cytoplasm.
• nucleus.
• chloroplasts.

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Section Quiz

• The net gain of ATP molecules after glycolysis is
• 3 ATP molecules.
• 2 ATP molecules.
• 3 pyruvic acid molecules.
• 4 pyruvic acid molecules

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Section Quiz

• Fermentation releases energy from food molecules
  in the absence of
• oxygen.
• glucose.
• NADH.
• alcohol.

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Section Quiz

• The first step in fermentation is always
• lactic acid production.
• the Krebs cycle.
• glycolysis.
• alcohol production.

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9-2 The Krebs Cycle and Electron Transport

• Oxygen is used for the final steps of cellular
  respiration. Because the pathway requires
  oxygen, it is said to be aerobic.
• In the presence of O2, pyruvic acid passes on to
  the second stage of cellular respiration, the
  Krebs cycle

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9-2 The Krebs Cycle and Electron Transport

• During the Krebs cycle, pyruvic acid is broken
  down into carbon dioxide in a series of
  energy-extracting reactions
• Net result of the Krebs cycle
• - 2 molecules of pyruvic acid enter
• - 8 molecules of NADH are gained
• - 2 molecules of FADH2 are gained
• - 2 molecules of ATP are gained

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Mitochondrion
Citric Acid Production
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9-2 The Krebs Cycle and Electron Transport

• From glycolysis and the Krebs cycle high energy
  electron carriers, NADH and FADH2, are produced.
  The electrons are then passed to the electron
  transport chain.
• The electron transport chain uses high energy
  electrons to convert ADP to ATP.
• ETC Movie pt 1
• ETC Movie pt 2

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9-2 The Krebs Cycle and Electron Transport
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9-2 The Krebs Cycle and Electron Transport
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9-2 The Krebs Cycle and Electron Transport
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9-2 The Krebs Cycle and Electron Transport
ATP synthase
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9-2 The Krebs Cycle and Electron Transport
Channel
ATP synthase
ATP
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9-2 The Krebs Cycle and Electron Transport

• Each NADH make 3 ATP while each FADH2 makes 2 ATP
• 1 glucose molecule can then make 38 total ATP ( 4
  ATP, 10 NADH ? 30 ATP, 2 FADH2 ? 4 ATP)
• Cellular Respiration Animation

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Section Quiz

• The Krebs cycle breaks pyruvic acid down into
• oxygen.
• NADH.
• carbon dioxide.
• alcohol.

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Section Quiz

• In eukaryotes, the electron transport chain is
  located in the
• cell membrane.
• inner mitochondrial membrane.
• cytoplasm.
• outer mitochondrial membrane.

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Section Quiz

• To generate energy over long periods, the body
  must use
• stored ATP.
• lactic acid fermentation.
• cellular respiration.
• glycolysis.

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Section Quiz

• Which statement correctly describes
  photosynthesis and cellular respiration?
• Photosynthesis releases energy, while cellular
  respiration stores energy.
• Photosynthesis and cellular respiration use the
  same raw materials.
• Cellular respiration releases energy, while
  photosynthesis stores energy.
• Cellular respiration and photosynthesis produce
  the same products.