Copyright Pearson Prentice Hall Cellular Respiration Photo Credit: Duomo Photography, Inc. Athletes get the energy they need from the break down of glucose during cellular respiration. Copyright Pearson Prentice Hall

What types of cells does CR take place in? Cellular respiration takes place in both ANIMAL and PLANT cells. 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 What organelle doe CR take place in? The MITOCHONDRIA is where cellular respiration takes place. Intermembrane space Outer membrane 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. Mitochondrion Matrix Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Key Facts about Cellular Respiration 1. Food is required. 2. The food is GLUCOSE (C6H12O6). 3. Glucose is broken down into ENERGY. 4. The energy made is in the form of ATP. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall The equation for cellular respiration is: 6O2 + C6H12O6 → 6CO2 + 6H2O + Energy oxygen + glucose → carbon dioxide + water + energy (ATP) What are the reactants? ___________ and __________ What are the products? _________ and ________ and ____________ Copyright Pearson Prentice Hall

Overview of Cellular Respiration What is 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

Copyright Pearson Prentice Hall Cellular Respiration has 3 parts: Glycolysis 2.Kreb Cycle (Citric Acid Cycle) 3. Electron Transport Chain (ETC) 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

Copyright Pearson Prentice Hall Anaerobic vs. Aerobic ANAEROBIC - no oxygen required GLYCOLYSIS, then FERMENTATION AEROBIC - oxygen required GLYCOLYSIS, then: CITRIC ACID CYCLE ELECTRON TRANSPORT CHAIN Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Glycolysis (part 1) Where does it take place? cytoplasm of cell (outside of mitochondria) What is it? A series of chemical reactions that break down glucose How? Breaks down glucose through chemical reactions Why? To make 2 molecules of pyruvic acid and 2 molecules of ATP Does it require oxygen? NO – it’s anaerobic Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Glycolysis ATP Production At the beginning of glycolysis, the cell uses up 2 molecules of ATP to start the reaction. 2 ATP 2 ADP 4 ADP 4 ATP Glycolysis is the first stage in cellular respiration. During glycolysis, glucose is broken down into 2 molecules of pyruvic acid. Glucose 2 Pyruvic acid Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Glycolysis When glycolysis is complete, 4 ATP molecules have been produced. 2 ATP 2 ADP 4 ADP 4 ATP Glucose 2 Pyruvic acid Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Glycolysis This gives the cell a net gain of 2 ATP molecules. 2 ATP 2 ADP 4 ADP 4 ATP Glucose 2 Pyruvic acid Copyright Pearson Prentice Hall

Kreb Cycle (Citric Acid Cycle) [Part 2] Where does it take place? Mitochondria (inner matrix) What is it? A series of chemical reactions that breaks down pyruvic acid How? Pyruvic acid is changed into acetyl-CoA then to Citric Acid -then to other carbon compounds Why? Makes Carbon Dioxide and 2 ATP Does it require oxygen? YES – it’s aerobic! Copyright Pearson Prentice Hall

The Krebs cycle begins when pyruvic acid produced by glycolysis enters the mitochondrion. Copyright Pearson Prentice Hall Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Electron Transport Chain (ETC) [Part 3] Where? Mitochondria (inner membrane) What? Energized electrons move from protein to protein located in the inner membrane of mitochondria How? NADH and FADH2 give up electrons Why? To make 32 ATP!!! Does it require oxygen? YES – it’s aerobic! Copyright Pearson Prentice Hall

Electron Transport High-energy electrons from NADH and FADH2 are passed along the electron transport chain from one carrier protein to the next. Copyright Pearson Prentice Hall Copyright Pearson Prentice Hall

Electron Transport As it rotates, the enzyme grabs a low-energy ADP, attaching a phosphate, forming high-energy ATP. Channel ATP synthase ATP Copyright Pearson Prentice Hall Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Fermentation Fermentation What happens when oxygen is not present? Fermentation takes place after glycolysis. NO KREBS CYCLE OR ETC!!!! Fermentation releases energy from food molecules by producing ATP in the absence of oxygen. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Fermentation What are the two main types of fermentation? Lactic Acid Fermentation Alcoholic Fermentation Copyright Pearson Prentice Hall

(b) Lactic acid fermentation Fig. 9-18b 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 NAD+ 2 NADH + 2 H+ 2 Pyruvate Figure 9.18b Fermentation 2 Lactate (b) Lactic acid fermentation

(a) Alcohol fermentation Fig. 9-18a 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 Pyruvate 2 NAD+ 2 NADH 2 CO2 + 2 H+ Figure 9.18a Fermentation 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation

Copyright Pearson Prentice Hall FERMENTATION When? When cells are short on oxygen What? Anaerobic process that follows glycolysis until oxygen is available. How? Lactic Acid Fermentation or Alcoholic Fermentation Why? To produce energy when oxygen is low Requires Oxygen? No- it’s anaerobic! Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall FERMENTATION LACTIC ACID Glucose Pyruvic Acid Lactic Acid + 2ATP Occurs in bacteria, plants, and animals Muscle fatigue ALCOHOLIC Glucose Pyruvic Acid Alcohol + 2ATP + CO2 Yeast Copyright Pearson Prentice Hall

Ethanol or lactate Citric acid cycle Fig. 9-19 Glucose Glycolysis CYTOSOL Pyruvate O2 present: Aerobic cellular respiration No O2 present: Fermentation MITOCHONDRION Ethanol or lactate Acetyl CoA Figure 9.19 Pyruvate as a key juncture in catabolism Citric acid cycle

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