Go to Section: Cellular Respiration Chapter 9

Go to Section: Interest Grabber Feel the Burn Do you like to run, bike, or swim? These all are good ways to exercise. When you exercise, your body uses oxygen to get energy from glucose, a six-carbon sugar. Section How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? 2.What do you think is happening in your cells to cause the changes in how you feel? 3.Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain.

Go to Section: Section Outline I.Chemical Pathways A.Chemical Energy and Food 1. one gram of sugar glucose (C 6 H 12 O 6 ) has 8311 calories 2. calorie a. The amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius b. Food labels actually list kilocalories Section 9-1

Go to Section: B. Cellular Respiration 1. the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Tertiary Consumers Secondary Consumers Primary Consumers Producers Energy Pyramid Cellular Respiration Photosynthesis

Go to Section: 2. Formulas sugars + oxygen carbon dioxide + water C 6 H 12 O 6 + O 2 CO 2 + H 2 O 666

Go to Section: Glucose Glycolysis Krebs cycle Electron transport Fermentation (without oxygen) Alcohol or lactic acid Chemical Pathways Section 9-1

Go to Section: C. Glycolysis 1. first set of reactions in cellular respiration 2. the process in which one molecule of glucose is broken in half producing two molecules of pyruvic acid 3. does not require oxygen 4. uses 2 ATP, but makes 4 ATP

Go to Section: D. Fermentation 1. releases energy from food molecules by producing ATP in the absence of oxygen 2. anaerobic a. Not in air – absence of oxygen 3. Two types of fermentation a. Alcoholic fermentation b. Lactic acid fermentation

Go to Section: 4. Alcoholic Fermentation a. formula Pyruvic + NADH  alcohol + CO 2 + NAD + acid b. Yeast making bread c. Alcohol

Go to Section: 5. Lactic Acid Fermentation a. formula Pyruvic + NADH  lactic + CO 2 + NAD + acid acid b. this process regenerates NAD+ so that glycolysis can continue c. Heavy exercise – burning d. Cheese, yogurt, buttermilk, sour cream, pickles, sauerkraut, kimchi

Go to Section: Section Outline II. The Krebs Cycle and Electron Transport A.Aerobic 1. in the presence of oxygen B.Krebs Cycle 1. pyruvic acid is broken down into carbon dioxide in a series of energy- extracting reactions Section 9-2

Go to Section: Flowchart Section 9-2 Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) Cellular Respiration

Go to Section: C. Electron Transport 1. the electron transport chain uses the high-energy electrons from the Krebs cycle to convert ADP into ATP

Go to Section: D. The TOTALS 1. in the absence of oxygen/anaerobic – only 2 molecules of ATP are created

Go to Section: more ATP molecules are produced

Go to Section: 3. These 36 ATP molecules represent about 38% of the total energy of glucose 4. The cell is actually more efficient than a typical automobile burning gasoline 5. The other 62% is lost at heat

Go to Section: E. Energy and Exercise 1. Quick Energy a. Cells usually contain enough stored ATP for a few seconds of intense exercise

Go to Section: b. Then, ATP is produced via lactic acid fermentation which can produce enough ATP to last about 90 seconds 1) lactic acid builds up causing sore muscles 2) sprinters breathe heavy to replace the oxygen

Go to Section: 2. Long-Term Energy a. Cellular respiration is the only way to get enough ATP for exercise longer than 90 sec. b. Energy is released slowly

Go to Section: The end

Section 1 Answers Interest Grabber Answers 1.How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? Students may answer that they feel no fatigue at the start of a run; however, after 1 minute and more so after 10 minutes, they are breathing hard, their heart rate has increased significantly, and their muscles may hurt. 2.What do you think is happening in your cells to cause the changes in how you feel? Students may say that the increase in heart rate and breathing rate are a response that gets extra oxygen to the cells. The pain may be attributed to the cells becoming fatigued. 3.Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer. Students may know that very high levels of performance can be sustained only very briefly even among the best of athletes. Students may say that the body runs out of readily available energy, food, or oxygen, or that the body builds up too many waste products in the cells.