Chapter 8: Glycolysis and Cellular Respiration lemastm/Teaching/BI102/Chapter 08 - Cellular...Harvesting Energy: Glycolysis and Cellular Respiration ... Figure 8.3 / 8.5 –Audesirk2 Byers ... Glycolysis and Cellular Respiration

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    Chapter 8

    Harvesting Energy: Glycolysis and Cellular Respiration

    Chapter 8: Glycolysis and Cellular Respiration

    What is Glucose Metabolism?

    Photosynthesis:

    = 6 CO2

    Carbon

    dioxide

    + 6 H2O

    Water

    C6H12O6Glucose

    + 6 O2

    Oxygen

    Glucose Metabolism:

    + Energy

    Chemical (40%)

    Heat (60%)

    Answer: The breakdown of glucose to release energy from

    chemical bonds

    + LightEnergy

    6 CO2Carbon

    dioxide

    + 6 H2O

    Water

    = C6H12O6Glucose

    + 6 O2Oxygen

    Major Steps of Glucose Metabolism

    Glucose

    1) Glycolysis (2 ATP)

    PyruvateNo oxygen present

    (Anaerobic)

    2) Fermentation

    Ethanol

    Lactate

    Oxygen present

    (Aerobic)

    3) Cellular Respiration(36 ATP)

    Carbon Dioxide

    Water

    Cytoplasm

    Mitochondria

    Chapter 8: Glycolysis and Cellular Respiration

    Glucose Metabolism:

    Chapter 8: Glycolysis and Cellular Respiration

    Figure 8.1 Audesirk2 & Byers

    1) Glycolysis (Greek: To break down a sweet)

    Ancient biochemical pathway (all organisms do it...)

    Occurs in cytoplasm; does not require oxygen

    Major Steps:

    A) Glucose Activation: Initiation of the reaction (takes energy)

    2 ATP 2 ADP

    (Activation Energy)C C C CCC

    Glucose

    Chapter 8: Glycolysis and Cellular Respiration

    CCC x 2

    P

    Glyceraldehyde

    3-phosphate

    (G3P)

    x 2

    1) Glycolysis (Greek: To break down a sweet)

    Ancient biochemical pathway (all organisms do it...)

    Occurs in cytoplasm; does not require oxygen

    Major Steps:

    A) Glucose Activation: Initiation of the reaction (takes energy)

    B) Energy Harvesting: Completion of the reaction ( to make energy)

    Chapter 8: Glycolysis and Cellular Respiration

    4 ADP 4 ATP

    CCC x 2

    P

    Glyceraldehyde

    3-phosphate

    (G3P)

    2 NAD+ 2 NADH

    CCC x 2

    Pyruvate

  • 2

    Net ATP Gain = 2 ATP

    Chapter 8: Glycolysis and Cellular Respiration

    Glycolysis in Review:

    Figure 8.2 Audesirk2 & Byers

    Major Steps of Glucose Metabolism

    Glucose

    1) Glycolysis (2 ATP)

    PyruvateNo oxygen present

    (Anaerobic)

    2) Fermentation

    Ethanol

    Lactate

    Oxygen present

    (Aerobic)

    3) Cellular Respiration(36 ATP)

    Carbon Dioxide

    Water

    Chapter 8: Glycolysis and Cellular Respiration

    2) Fermentation: Process for regenerating NAD+ for glycolysis

    Crucial for organisms that live where O2 is rare (e.g., intestines / soils / bogs)

    A) Lactate Fermentation: Pyruvate converted to lactate (lactic acid)

    CCC x 2

    Lactate

    CCC x 2

    Pyruvate

    2 NADH 2 NAD+ (Back to glycolysis)

    Chapter 8: Glycolysis and Cellular Respiration

    Types of Fermentation:

    Does NOT

    produce ATP!

    Lactate Fermentation:

    Chapter 8: Glycolysis and Cellular Respiration

    Figure 8.3 / 8.4 Audesirk2 & Byers

    2) Fermentation: Process for regenerating NAD+ for glycolysis

    Crucial for organisms that live where O2 is rare (e.g., intestines / soils / bogs)

    A) Lactate Fermentation: Pyruvate converted to lactate (lactic acid)

    B) Alcoholic Fermentation: Pyruvate converted to ethanol and CO2

    Chapter 8: Glycolysis and Cellular Respiration

    Types of Fermentation:

    Does NOT

    produce ATP!

    CCC x 2

    Ethanol

    x 2

    Carbon

    Dioxide

    +CCC x 2

    Pyruvate

    2 NADH 2 NAD+ (Back to glycolysis)

    Alcoholic Fermentation:

    Chapter 8: Glycolysis and Cellular Respiration

    Figure 8.3 / 8.5 Audesirk2 & Byers

    Yeast

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    Major Steps of Glucose Metabolism

    Glucose

    1) Glycolysis (2 ATP)

    PyruvateNo oxygen present

    (Anaerobic)

    2) Fermentation

    Ethanol

    Lactate

    Oxygen present

    (Aerobic)

    3) Cellular Respiration(36 ATP)

    Carbon Dioxide

    Water

    Chapter 8: Glycolysis and Cellular Respiration

    3) Cellular Respiration: Series of reactions that produces ATP

    Occurs in mitochondria / requires oxygen

    Chapter 8: Glycolysis and Cellular Respiration

    = CO2Carbon

    Dioxide

    + H2O

    Water

    Pyruvate + O2Oxygen

    + ATP

    Chemical

    Energy

    Mitochondria have two membranes

    Outer membrane (smooth)

    Inner membrane (folded cristae)

    Mitochondria have two compartments

    Intermembrane compartment

    Matrix

    Recall from Chapter 4:

    Figure 4.17 Audesirk2 & Byers

    3) Cellular Respiration: Series of reactions that produces ATP

    Occurs in mitochondria / requires oxygen

    Chapter 8: Glycolysis and Cellular Respiration

    Sequence of Events:

    A) Pyruvate diffuses into mitochondrial matrix

    Travels down concentration gradient (via pores)

    B) Pyruvate converted to acetyl CoA:

    CC - CoA x 2

    Acetyl CoANAD+ NADH

    Coenzyme A CO2

    C( x 2)

    CCC x 2

    Pyruvate

    3) Cellular Respiration: Series of reactions that produces ATP

    Occurs in mitochondria / requires oxygen

    Chapter 8: Glycolysis and Cellular Respiration

    Sequence of Events:

    C) Krebs Cycle:CC - CoA (x 2)

    Acetyl CoA

    Krebs

    Cycle

    2 CO2C( )C(x 2)

    FAD

    FADH2

    (x 2)

    3 NAD+

    3 NADH

    (x 2)

    ADP

    ATP

    (x 2)

    DO NOT

    COPY!

    Chapter 8: Glycolysis and Cellular Respiration

    The True Story:

    The Krebs Cycle is also

    called the Citric Acid Cycle

    Figure E8.3 Audesirk2 & Byers

    Review of Cellular Respiration:

    Chapter 8: Glycolysis and Cellular Respiration

    Energy Checklist (per glucose):

    1) 2 ATP

    2) 10 Electron-carrier Molecules

    NADH (8)

    FADH2 (2)

    Figure 8.7 Audesirk2 & Byers

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    3) Cellular Respiration: Series of reactions that produces ATP

    Occurs in mitochondria / requires oxygen

    Chapter 8: Glycolysis and Cellular Respiration

    Sequence of Events:

    D) Electron Transport Chain:

    Location where electron-carrier molecules unload their electrons

    Located in the inner

    mitochondrial membrane

    Outer

    Membrane

    Inner

    Membrane

    Intermembrane Compartment

    Matrix

    ETC

    NAD+

    FAD

    NADH

    FADH2

    2e-

    H+H+H+

    1/2 O2 + 2 H+ H2O

    2e-

    2e-

    Electron Transport Chain: Cyanide

    Chapter 8: Glycolysis and Cellular Respiration

    Similar to Figure 8.8 Audesirk2 & Byers

    3) Cellular Respiration: Series of reactions that produces ATP

    Occurs in mitochondria / requires oxygen

    Chapter 8: Glycolysis and Cellular Respiration

    Sequence of Events:

    E) Chemiosmosis:

    Utilizes energy stored in H+ gradient to generate ATP

    Located in the inner

    mitochondrial membrane

    H+

    H+H+ H+

    H+

    H+

    H+

    H+

    H+H+

    H+

    ATPADP

    32 ATP

    Outer

    Membrane

    Inner

    Membrane

    Intermembrane Compartment

    Matrix

    ETC

    H+ H+ H+

    H+ ion

    channel

    H+ (See A Closer Look - Chemiosmosis: Chloroplasts Pg. 124)

    ATP diffuses out of mitochondria

    to provide energy for cellular processes

    Chapter 8: Glycolysis and Cellular Respiration

    Chemiosmosis:

    Figure 8.8 Audesirk2 & Byers

    Final Tally of Energy

    Production:

    One Molecule of Glucose

    Yields 36 - 38 ATP

    Yippee!

    Chapter 8: Glycolysis and Cellular Respiration

    Figure 8.10 Audesirk2 & Byers

    Multiple Biomolecules Yield Energy:

    (See Health Watch - Pg. 144)

    Fats:

    Glycerol Enters glycolysis

    Fatty Acids Enters Krebs cycle

    Reversal true as well:

    Glucose Fats

    Chapter 8: Glycolysis and Cellular Respiration

    Proteins:

    Enter at multiple stages

    Figure E8.4 Audesirk2 & Byers

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