2. Cellular respiration uses oxygen to convert the chemical energy stored in organic molecules into -?-

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1 HB Cell Respiration Questions (1/2 point each question or blank to fill in 37 points) 1. Organisms, such as plants that make their own food are called -?- 2. Cellular respiration uses oxygen to convert the chemical energy stored in organic molecules into -?- 3. What is the correct chemical equation for cellular respiration? 4. What is released during cellular respiration? 5. Cellular respiration is called an aerobic process because it requires -?- 6. How are breathing and cellular respiration related? 7. What are the inputs and outputs of cellular respiration? Concept 7.3 ATP provides energy for cellular work. (pg ) ATP, adenosine triphosphate, is a molecule made of a nitrogen-containing compound (adenine), a five carbon sugar (ribose), and a tail made of three phosphate groups. The triphosphate tail has potential energy because the negatively charged phosphate groups are crowded together. When a phosphate bond is broken, some of the potential energy is released. The released phosphate group can bond to another molecule and enable it to do work. Cells perform three main types of work: chemical, mechanical, and transport. An example of chemical work is building large molecules such as proteins. The contraction of a muscle is mechanical work. Pumping ions across a cellular membrane is transport work. Once used, ATP can be recycled. The energy needed to recharge ATP comes from food.

2 8. How is energy released from ATP? 9. What are the three main types of cellular work? Concept 7.4 Electrons fall from food to oxygen during cellular respiration. (pg ) Cellular respiration is an aerobic process, meaning that it requires oxygen. Although cellular respiration is different from breathing (called respiration), the two processes are related. Breathing brings oxygen into the body where it is used for cellular respiration. Breathing also released carbon dioxide, the e waste product of cellular respiration. The overall equation for cellular respiration is Glucose + oxygen --- carbon dioxide + water + energy (ATP) In this process, up to 38 ATP molecules are produced from each molecule of glucose. Glucose is broken down in several steps. Molecules called electron carriers accept many of the high-energy electrons released from glucose. The electron carriers pass the electrons to other carriers in series of transfers called the electron transport chain. At the end of the chain, oxygen pulls electrons from the final carrier molecule. These electrons join with hydrogen ions, forming water. As electrons undergo each transfer in the chain, they release a little energy, which is used to make ATP. 10. How is breathing related to cellular respiration? 11. What are the products of cellular respiration? 12. What happens to electrons in the electron transport chain? Concept 7.5 Cellular respiration converts energy in food to energy in ATP (pg ) Many enzymes involved in cellular respiration are built into the inner membranes of mitochondria. The complex folding of the inner membranes creates many sites where these reactions can occur. A specific enzyme speeds up each reaction. Cellular respiration is just one chemical process that takes place in cells. All of the chemical processes in a cell make up the cell s metabolism. Cellular respiration has three main stages. Glycolysis, the first stage, occurs in the cytoplasm. In glycolysis, two ATP molecules help break down glucose into two molecules of pyruvic acid. Four new ATP molecules are also produced. Each of the two pyruvic acid molecules are then converted to acetyl CoA. In the Krebs cycle, each acetyl CoA molecule is made. The Krebs cycle occurs in the matrix of the inner mitochondrion. This stage has two parts: and electron transport chain and ATP production. The carrier molecule NADH transfers electrons to the electron transfer chain. Each transfer releases a small amount of energy. ATP synthase is an enzyme that uses the energy to produce up to 34 ATP molecules per glucose molecule. Cellular respiration can produce a total of up to 38 ATP from one glucose molecule. 13. How does the structure of a mitochondrion maximize its production of ATP? 14. What occurs during glycolysis?

3 15. How many ATP molecules can be made from each glucose molecule in cellular respiration? Concept 7.6 Some cells can harvest energy without oxygen (pg ) At some times, such as when you sprint, your lungs and bloodstream can t supply oxygen fast enough to meet your muscles need for ATP. In such situations, muscle cells rely on fermentation. Fermentation makes ATP entirely from glycolysis without using oxygen. Your body uses oxygen to convert lactic acid back to pyruvic acid. Like your muscle cells, yeast cells are capable of both cellular respiration and fermentation. In an anaerobic environment, an environment without oxygen, yeast cells ferment sugar and other foods. Yeast fermentation produces alcohol instead of lactic acid, and also releases carbon dioxide. Yeast fermentation is used to make beer, wine and bread. Some fungi and bacteria that produce lactic acid during fermentation are used to make cheese and yogurt, soy sauce and sauerkraut. 16. How is ATP made during fermentation? 17. List four food products made by fermentation. Vocabulary Review and Reflection In write the letter of the correct definition on the line next to each term. 18. Electron transport chain 19. Producer 20. Anaerobic 21. Chemical energy 22. Cellular respiration a. term that describes an environment without oxygen b. process that uses oxygen to release the energy in glucose and produce ATP c. Potential energy due to the arrangement of atoms in molecules d) series of electron transfers that release energy e) organism that produces food for itself and other organisms

In 23-26, fill in the blanks with the appropriate terms from the chapter. 23. In the second stage of cellular respiration, called, carbon dioxide and ATP are produced. 24.

4 In 23-26, fill in the blanks with the appropriate terms from the chapter. 23. In the second stage of cellular respiration, called, carbon dioxide and ATP are produced. 24. The amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius is a(n) 25. The process in which plants use the sun s energy to convert water and carbon dioxide into sugars is called 26. The molecule uses energy to convert ADP to ATP. In 27-29, study the diagram. Then fill in the blanks to show where the three stages of cellular respiration occur in the mitochondrion Word-Wise Use the clues to unscramble the Key Terms. Then write the terms in the appropriate blanks Mucosner metharl genrey ricobea mistamelob temnfatonier PTA 30. requiring oxygen 31. all of a cell s chemical processes 32. source of energy used by cells 33. the random energy of molecules 34. organism that obtains food by eating other organisms 35. process of making ATP without oxygen

5 ATP Provide Energy for Cellular Work ATP stands for ADENOSINE TRIPHOSPHATE. The adenosine part consists of a nitrogen-containing compound called adenine and a five carbon sugar called ribose. The triphosphate tail consists of three phosphate groups. The tail is the business end of ATP. It is the source of energy used for most cellular work. Each phosphate group is negatively charged. Because like charges repel, the crowding of negative charge in the ATP tail contributes to the potential energy stored in ATP. You can compare this to storing energy by compressing a spring. The tightly coiled spring has potential energy. When the compressed spring relaxes, its potential is released. The spring s kinetic energy can be used to perform work such as pushing a block attached to one end of the spring. The phosphate bonds can be symbolized by springs. When the ATP is involved in a chemical reaction that breaks one or both of these phosphate bonds, potential energy is released. In most cases of cellular work, only one phosphate is lost from ATP. Then the tail of the molecule has only two phosphate groups left. The resulting molecule is called adenosine diphosphate or ADP. Define: 36. ATP 37. Adenosine 38. Ribose 39. Triphosphate tail 40. Adenosine diphosphate or ADP Label the parts of this diagram as indicated: (41-46)

6 ATP and Cellular Work During a chemical reaction that breaks one of ATP s bonds, the phosphate group is transferred from ATP to another molecule. Specific enzymes enable this transfer to occur. The molecule that accepts the phosphate undergoes a change, driving the work. Your cells perform three main types of work: chemical work, mechanical work, and transport work. An example of chemical work is building large molecules such as proteins. ATP provides the energy for the dehydration synthesis reaction that links amino acids together. An example of mechanical work is the concentration of muscles. In your muscle cells, ATP transfers phosphate groups to certain proteins. These proteins change shape, starting a chain of events, which will cause muscle cells to contract. An example of transport work is pumping solutes such as ions across a cellular membrane. Again, the transfer of a phosphate group from ATP causes the receiving membrane protein to change shape, enabling ions to pass through. Write an example of: 47. Chemical work: 48. Mechanical work: 49. Transport work: The ATP CYCLE ATP is continuously converted to ADP as your cells do work. Fortunately, ATP is recyclable. For example, ATP can be restored from ADP by adding a third phosphate group. Like compressing a spring, adding the phosphate group requires energy. The source of this energy is organic molecules form food. ATP operates in a cycle within your cells. Works consumes ATP, which is then regenerated from ADP and phosphate. The ATP cycle churns at an astonishing pace. A working muscle cell recycles all of its ATP about once each minute. That s about 10 million ATP molecules spent and regenerated per second. 50. The source of energy for regeneration ATP and ADP is

7 Label the diagram below as indicated. (51-58) Fill in the blanks (57-62) 57. process inputs outputs

8 Label the following diagram (63-73)

CELLULAR RESPIRATION REVIEW MULTIPLE CHOICE. Circle ALL that are TRUE. There may be MORE THAN one correct answer. 1. is the first step in cellular res

CELLULAR RESPIRATION REVIEW MULTIPLE CHOICE. Circle ALL that are TRUE. There may be MORE THAN one correct answer. 1. is the first step in cellular respiration that begins releasing energy stored in glucose.