Chapter 7: The Working Cell: Energy from Food

Transcription

1 Chapter 7: The Working Cell: Energy from Food Online Activity 7.1: Sunlight Powers Life Producers are plants, algae and some bacteria. These use photosynthesis to make food from water, carbon dioxide and minerals. The producers can then use this energy themselves (respiration), or other organisms, the consumers, can utilize it for energy (also respiration). 1. Who uses photosynthesis, a producer or consumer? 2. What is an example of a producer? A consumer? All organisms need energy to grow, develop, and maintain a living state. This energy is acquired from the chemical energy in food through a process called cellular respiration. 1. Photosynthesis: What does the tree need (the reactants) to produce glucose and oxygen? 3 things. 2. Plant Cell Respiration: What is formed/released when oxygen and glucose combine? 3 things 3. Plant Cell Work: What is formed on this tree when ATP is stored? 4. Animal Cell Respiration: When the bear eats the apple, and the glucose (from the apple) combines with oxygen, what is released? 3 things 5. The bear used the stored apple energy, glucose, which released ATP, to do what? Online Ch 7 Cellular Respiration 1

2 Page 3 Explore the processes of photosynthesis and respiration in more depth. When needed include the chemical reaction!! 1. What happens when sunlight shines on the plant? 2. How does the plant release the energy that is now stored in sugar? 3. How is the energy in ATP used by the plant? 4. How does an animal release the energy used in sugar? 5. How is the energy in ATP used by animals? 6. What starts the whole process? Page 4 More exploration on the processes of photosynthesis and respiration. 1. Usually, what is the ultimate source of energy on Earth? 2. What high energy molecule is a product of photosynthesis? And needed for respiration 3. In both plants and animals, respiration releases what three molecules? 4. What is the major energy carrier to do work in plants and animals? 5. Cellular respiration uses two reactants? 6. Cellular respiration gives off what two products? To make what? 7. Where does the majority of this energy come from? Online Ch 7 Cellular Respiration 2

3 Online Activity 7.2: Food stores chemical energy Compare what happens to the chemical energy in food when consumed by fire and by a human. 1. What happens when a marshmallow is put over a flame and burnt? (What is used and produced?) 2. What happens when Tom eats the marshmallow? (What is used and produced?) 3. What is the same between burning a marshmallow and eating it? 4. What is different between burning a marshmallow and eating it? Online Ch 7 Cellular Respiration 3

4 Online Activity 7.3: ATP provides energy for cellular work Discover how ATP stores energy. Cells cannot directly use the energy stored in food they must change it into a more usable form, stored in a molecule called ATP (adenosine triphosphate). 1. What are some examples of ATP at work? Plant (two examples): Lizard (three examples): Bug (one example): ATP (adenosine triphosphate) is composed of a molecule called adenosine with three attached phosphate groups. ATP stores potential energy in the bonds between phosphate groups in the molecule. 1. Complete the equation of ATP releasing energy. three things ATP + H ATP is the abbreviation for? What does ADP stand for then? 3. What happens when the cell requires energy? 4. Energy is stored in what molecule until energy is needed in a cell? Online Ch 7 Cellular Respiration 4

5 Online Activity 7.4: Electrons fall during cellular respiration One of the most famous dirigibles was a German model, the "Hindenburg." It was filled with about 200,000 cubic meters (seven million cubic feet) of hydrogen gas. In 1937, as the Hindenburg landed in New Jersey, the hydrogen gas somehow ignited with the oxygen from the atmosphere. 1. The Hindenburg blimp was really a. 2. What is the chemical reaction that exploded the Hindenburg? Understand how oxygen and hydrogen react to release energy. 1. Why don't you explode in a ball of flames? cont : The combustion of sugar is completed with steps by which cells release the energy. In cells, electrons pass from sugar to NADH and then to electron transport chains. 1. In one quickstep, what leaves the sugar to make energy? 2. In many short steps, what leaves the sugar to make ATP? 3. Which line, A or B, is similar to what happened to the Hindenburg? Why? 4. Which line represents the energy being released in small, useable amounts? This is called the? (three words) 5. This statement is incorrect: Process B releases more energy that process A. Why? Online Ch 7 Cellular Respiration 5

6 Online Activity 7.5: Cellular Respiration converts food energy into ATP The three stages of respiration glycolysis, the Krebs cycle, and the electron transport chain generate ATP. 1. Where does glycolysis begin? Where does the Krebs Cycle and ETC take place? Compare the output of the three stages of respiration. 1. What are the three stages of respiration? Glycolysis: 1. How many ATP s are required to start glycolysis? 2. What is the final net gain of ATP in glycolysis? Krebs Cycle: 3. What comes after gycolysis? (Krebs cycle or ETC ) 4. How many ATP s were made in the second stage, the Krebs cycle? Electron Transport Chain: 5. How many ATP s were made the third stage, the electron transport chain? Conclusion: 6. List, in order, the correct order of ATP production? (ETC, glycolysis, Krebs) 7. Which process needs oxygen? 8. What gas is a by-product of the Krebs cycle? 9. What is a by-product of the ETC? 10. Which process, in the cytoplasm, does not need oxygen? 11. Why do you, a human, need oxygen to survive? Online Ch 7 Cellular Respiration 6

7 Online Activity 7.6: Some cells don t need oxygen Sometimes cells do not have enough oxygen for cellular respiration to make all the ATP they need. In that case, many cells add a second process, fermentation, to make more ATP. Why would a cell begin fermentation? Fermentation occurs where in the cell? What steps are NOT used ( skipped ) in fermentation? Discover how many ATP s are produced in fermentation. 1. Fermentation begins with high or low oxygen concentration? 2. How many ATP s are needed to start fermentation? 3. In what part of the cell does fermentation take place? 4. Compare the number of ATP molecules made in glycolysis fermentation to the number made in cellular respiration. What is the difference? 5. What is the final net gain of ATP molecules when a molecule of glucose undergoes glycolysis and fermentation? 6. What is happens in your leg muscles when you run up around, hard, for a basket ball game? 7. What happens to your breathing rate when you exert yourself a lot? Why? Online Ch 7 Cellular Respiration 7