Copyright Pearson Prentice Hall 9-1 Chemical Pathways Photo Credit: Duomo Photography, Inc. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 9-1 Chemical Pathways Food serves as a source of raw materials for the cells in the body and as a source of energy. Animal Cells Animal Mitochondrion Plant Photo Credits: left: ©Bob Gurr/DRK Photo; middle bottom: ©John Durham/Science Photo Library/Photo Researchers, Inc. ; middle top: ©Ron Boardman/Stone; right: ©Keith Porter/Photo Researchers, Inc. Plant Cells Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Both plant and animal cells carry out the final stages of cellular respiration in the mitochondria. Animal Cells Outer membrane Intermembrane space Mitochondrion Inner membrane Photo Credits: left: ©Bob Gurr/DRK Photo; middle bottom: ©John Durham/Science Photo Library/Photo Researchers, Inc. ; middle top: ©Ron Boardman/Stone; right: ©Keith Porter/Photo Researchers, Inc. Matrix Plant Cells Copyright Pearson Prentice Hall

Chemical Energy and Food One gram of the sugar glucose (C6H12O6), when burned in the presence of oxygen, releases 3811 calories of heat energy. A calorie is the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius. Copyright Pearson Prentice Hall

Overview of Cellular Respiration What is cellular respiration? Copyright Pearson Prentice Hall

Overview of Cellular Respiration Cellular respiration is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen. Copyright Pearson Prentice Hall

Overview of Cellular Respiration Electrons carried in NADH Electrons carried in NADH and FADH2 Pyruvic acid Glucose Glycolysis Cytoplasm Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria. Mitochondrion Copyright Pearson Prentice Hall

Overview of Cellular Respiration Glycolysis takes place in the cytoplasm and is an anaerobic process. The Krebs cycle and electron transport take place in the mitochondria and both are aerobic processes. Glycolysis Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria. Cytoplasm Mitochondrion Copyright Pearson Prentice Hall

Overview of Cellular Respiration Glycolysis must take place first. anaerobic process (does not require oxygen) takes place in cytoplasm splits glucose into two three-carbon molecules produces two ATP molecules Glycolysis Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria. Cytoplasm Mitochondrion Copyright Pearson Prentice Hall

Overview of Cellular Respiration 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and The Krebs cycle transfers energy to an electron transport chain. takes place in mitochondrial matrix breaks down three-carbon molecules (pyruvate) from glycolysis makes a small amount of ATP releases carbon dioxide transfers energy-carrying molecules Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria. Mitochondrion Copyright Pearson Prentice Hall 10

Overview of Cellular Respiration 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and The electron transport chain produces a large amount of ATP. takes place in inner membrane energy transferred to electron transport chain oxygen enters process ATP produced Water is released as a waste product Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria. Mitochondrion Copyright Pearson Prentice Hall 11

Electron Transport Chain Flowchart Section 9-2 Cellular Respiration Carbon Dioxide (CO2) + Water (H2O) ATP Glucose (C6H1206) + Oxygen (02) Glycolysis Krebs Cycle Electron Transport Chain

Total ENERGY Yield Glycolysis 2 ATP Krebs Cycle 2 ATP ETC  32 ATP Total 36 ATP

Overview of Cellular Respiration Cellular respiration is like a mirror image of photosynthesis. The reactants in photosynthesis are the same as the products of cellular respiration. Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria. Copyright Pearson Prentice Hall 14

Overview of Cellular Respiration The equation for cellular respiration is: 6O2 + C6H12O6 → 6CO2 + 6H2O + Energy oxygen + glucose → carbon dioxide + water + Energy Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Glycolysis The Advantages of Glycolysis The process of glycolysis is so fast that cells can produce thousands of ATP molecules in a few milliseconds. Glycolysis does not require oxygen. So what happens is no O2 is available? Cellular respiration stops… Copyright Pearson Prentice Hall

Aerobic vs. Anaerobic Anaerobic DOES NOT require oxygen Simple fast produces smaller amounts of energy (ATP) Aerobic requires oxygen Yields large amounts of energy What is this energy molecule? ATP, ATP, ATP

Copyright Pearson Prentice Hall Fermentation Fermentation When oxygen is not present, glycolysis is followed by a different pathway. The combined process of this pathway and glycolysis is called fermentation. Fermentation is the process that allows glycolysis to continue to ATP when oxygen is not available. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Fermentation What are the two main types of fermentation? Alcohol fermentation Lactic acid fermentation Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Fermentation Alcoholic Fermentation Yeasts and a few other microorganisms use alcoholic fermentation, forming ethyl alcohol (to make alcoholic beverages) and carbon dioxide (what makes bread rise) as wastes. The equation for alcoholic fermentation after glycolysis is: pyruvic acid + NADH → alcohol + CO2 + NAD+ Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Fermentation Lactic Acid Fermentation In many cells (of bacteria, plants and most animals), pyruvic acid that accumulates as a result of glycolysis can be converted to lactic acid. The equation for lactic acid fermentation after glycolysis is: pyruvic acid + NADH → lactic acid + NAD+ Sometimes happens in your muscles (burning or cramps) from exercise. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Fermentation The first part of the equation is glycolysis. The second part shows the conversion of pyruvic acid to lactic acid. Lactic acid fermentation converts glucose into lactic acid. The first part of the equation is glycolysis. The second part shows the conversion of pyruvic acid to lactic acid. Copyright Pearson Prentice Hall

Fermentation is used in food & beverage production. Uses Fermentation is used in food & beverage production. Yogurt Cheese Bread Beer and wine

Copyright Pearson Prentice Hall 9-1 Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 9-1 The raw materials required for cellular respiration are carbon dioxide and oxygen. glucose and water. glucose and oxygen. carbon dioxide and water. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 9-1 Glycolysis occurs in the mitochondria. cytoplasm. nucleus. chloroplasts. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 9-1 The net gain of ATP molecules after glycolysis is 3 ATP molecules. 2 ATP molecules. 3 pyruvic acid molecules. 4 pyruvic acid molecules Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 9-1 Fermentation releases energy from food molecules in the absence of oxygen. glucose. NADH. alcohol. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 9-1 The first step in fermentation is always lactic acid production. the Krebs cycle. glycolysis. alcohol production. Copyright Pearson Prentice Hall

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