 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. 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? 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 your answer.

Energy from Food Chap 7

 How are autotrophs and heterotrophs different? Give an example of each.

PRODUCERS - PHOTOAUTOTROPHS

PRODUCERS - CHEMOAUTOTROPHS

CONSUMERS - HETEROTROPHS

Concept 7.1 – Sunlight powers life. Describe how organisms release energy from food. Through cellular respiration, oxygen is used to release energy from glucose and produce ATP.

What are some types of energy?  Potential  Kinetic  Chemical

Concept 7.2 – Food stores chemical energy. 3. What is the difference between kinetic energy and potential energy? Kinetic energy is the energy of motion. Potential energy is energy that is stored.

Concept 7.2 – Food stores chemical energy. 4. How do cells release chemical energy from food? In cellular respiration, oxygen reacts with the organic molecules of food (sugar), breaking the molecules into smaller molecules and releasing chemical energy (ATP).

What are some activities that use energy?

Energy Consumed by Daily Activities What is ATP? Adenosine triphosphate. Is a nitrogen containing compound called adenine and a five carbon sugar called ribose. Has three phosphate groups.

7.3 ATP provides energy for cellular work  How is energy released from ATP?  Energy is released from ATP when a phosphate bond is broken.

Concept 7.3 – ATP provides energy for cellular work. 6. What are the three main types of cellular work? Chemical work, mechanical work, transport work (active transport)

7.4 Electrons fall  How is breathing related to cellular respiration? Breathing brings oxygen into the body that is required by cells for cellular respiration (mitochondria). Breathing also removes the waste product of cellular respiration, carbon dioxide.

Cellular Respiration Equation 8. What are the products of cellular respiration? Carbon dioxide, water, and energy (ATP)

7.5 Cellular Respiration  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. 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? 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 your answer.

Overview of Cellular Respiration  What is cellular respiration?  Cellular respiration is the process that releases energy by breaking down food (glucose) in the presence of oxygen.

Overview of Cellular Respiration  What is cellular respiration?  Cellular respiration is the process that releases energy by breaking down food (glucose) in the presence of oxygen. C 6 H 12 O O 2  6 H 2 O + 6 CO 2 + Energy glucose oxygen water carbon ATP dioxide  What would be the problem if cellular respiration occurred in just one step?  Burn up all energy instead of a gradual release of energy

Glucose Pyruvic acid Electrons carried in NADH Electrons carried in NADH and FADH 2 Cellular Respiration: An Overview Section 9-1 Glycolysis Krebs Cycle Electron Transport Chain Total ATP

Glycolysis  First step in cellular respiration  Glyco / lysis – “to break glucose”  Does not need oxygen to occur  Where does glycolysis take place in the cell?  Glycolysis occurs in the cytoplasm of the cell.  Glycolysis  Process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid.

Glycolysis How does the cell get glycolysis going?  The cell uses energy. 2 molecules of ATP are used up. What are the products of glycolysis?  Pyruvate and 4 ATP molecules

C. Glycolysis Why is there only a NET of 2 ATP molecules produced during glycolysis?  2 ATP molecules were used to start reaction

What happens after glycolysis??? Glycolysis is ALWAYS the first step in the break down of glucose.  Glycolysis does not need oxygen to occur If oxygen is NOT present, glycolysis is followed by anaerobic respiration.  Alcoholic Fermentation  Lactic Acid Fermentation

What happens after glycolysis??? Glycolysis is ALWAYS the first step in the break down of glucose. If oxygen is NOT present, glycolysis is followed by anaerobic respiration (Fermentation)  Alcoholic Fermentation  Lactic Acid Fermentation If oxygen is present, glycolysis is followed by aerobic respiration – a process that requires oxygen

Anaerobic Respiration: Fermentation  What is fermentation?  Fermentation is a process by which cells release energy in the absence of oxygen.  Where does fermentation occur in the cell?  Cytoplasm of the cell.  Why is fermentation considered an anaerobic process?  Anaerobic is process that does not require oxygen  Fermentation does NOT require oxygen

Anaerobic Respiration: Fermentation  Two main types of fermentation 1. Alcohol fermentation 2. Lactic acid fermentation

 What organisms use alcoholic fermentation o Yeasts and other microorganisms use alcoholic fermentation o Waste products are alcohol and carbon dioxide  What happens to the small amount of alcohol produced during the baking of bread?  Evaporates when bread is baked. Glycolysis Alcoholic Fermentation

 How does fermentation allow the production of ATP to continue?  NAD+ is looped to start the process over again. Glycolysis Alcoholic Fermentation

Glycolysis Lactic Acid Fermentation Section Lactic Acid Fermentation – Lactic acid is produced by your muscles during rapid exercise when not enough oxygen is present. Prokaryotes produce lactic acid as a waste product which is used in production of foods: yogurt, cheese, sour cream, sauerkraut, etc. Glucose2 Lactic acid2 Pyruvic acid

SUMMARY Glycolysis is ALWAYS the first step in the break down of glucose. If oxygen is NOT present, glycolysis is followed by anaerobic respiration.  Alcoholic Fermentation  Lactic Acid Fermentation If oxygen is present, glycolysis is followed by aerobic respiration. Glycolysis

The Krebs Cycle and Electron Transport 1. At the end of glycolysis, how much of the chemical energy in glucose is still unused? Approx. 90% 2. Because the final stages of cellular respiration require oxygen, they are said to be aerobic.

The Krebs Cycle and Electron Transport Mitochondrial matrix Where do the reactions of the Krebs cycle take place in the cell???

The Krebs Cycle and Electron Transport  The Krebs Cycle  Second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

Electron Transport Chain Inner membrane of mitochondria Where do the reactions of the electron transport chain take place in the cell???

The Electron Transport  The Electron Transport Chain  series of proteins in which the high-energy electrons from the Krebs cycle are used to convert ADP into ATP

Cellular Respiration and Energy In the presence of oxygen, the cell can produce 36 ATP molecules per one glucose molecule