Cellular Respiration Homework and Study Guide

(all questions are one point unless otherwise stated. Cellular Respiration Homework and Study Guide Directions: Below you will find a variety of questions on cellular respiration. As you will soon notice, the questions are of varying formats. For short answer questions, please write in complete sentences. For true/false questions, first determine if the statement is true or false. If the statement is false, correct the underlined word to make the statement true. As we cover this material on cellular respiration, you will be assigned some of these questions each night. When this assignment is complete, you will have a great study guide for the unit test. 1. (3 pts) What is cellular respiration? The process of releasing energy by the breaking down glucose or other food molecules in the presence of oxygen. 2. ______________________ What does ADP stand for? adenosine diphosphate 3. adenosine triphosphate ______________________ What does ATP stand for? 4. ______________________ Which molecule is energy-poor? ADP 5. ______________________ Which molecule is energy-rich? ATP 6. An ADP/ATP molecule consists of what three parts? Label these three parts in this diagram. (3 pts) chain of three phosphate groups adenine, a nitrogenous base ribose, a 5-carbon sugar Is the molecule in this diagram ADP or ATP? How do you know? ATP, there are three phosphates (2 pts) 7. What role does ADP/ATP play in living cells? basic unit of energy 8. (2 pts) Explain how energy is stored and released by ADP and ATP. stored: by adding a phosphate group to ADP forming ATP released: removing the third phosphate group from ATP creating ADP 1 True ___________ True or False. Food serves as a source of energy by being a fuel for cellular respiration, as well as by supplying the raw materials needed for the building of new molecules within a cell. two false 10. ___________ True or False. The difference between ADP and ATP is that ADP has three phosphate molecules. true 11. ___________ True or False. The energy that flows through the ecosystem cannot be recycled. can 12. ___________ True or False. The chemical elements essential for life cannot be recycled. false 9. 13. Briefly describe the relationship between photosynthesis and respiration. The products of photosynthesis are the reactants for cellular respiration and vice-versa. (2 pts) only green organisms 14. __________________________ Which organisms perform photosynthesis? all eukaryotes 15. __________________________ Which organisms perform cellular respiration? 16. __________________________ What are the products of photosynthesis? glucose and oxygen 17. __________________________ What are the reactants of photosynthesis? water and carbon dioxide 18. __________________________ What are the products of cellular respiration? water and carbon dioxide glucose and oxygen 19. __________________________ What are the reactants of respiration? f 20. _________ In which of the following ways is photosynthesis similar to respiration? (a) Both processes produce ATP. (b) Both processes produce ATP by generating energy from an electron transport chain to pump hydrogen protons to an area of higher concentration. (c) Both use ATP synthases to generate ATP. (d) Both processes produce PGAL. (e) Both processes involve energy transformations. (f) All of the above are correct. c 21. _________ Energy flows through living systems from: (a) the sun to heterotrophs and then to autotrophs (b) autotrophs to the environment and then to heterotrophs (c) the sun to autotrophs and then to heterotrophs (d) the environment to heterotrophs and then to autotrophs. 22. What is the equation for cellular respiration? (2 pts) (2 pts) (3 pts) C6H12O6 + 6 O2 ==> 6 CO2 + 6 H2O + 38 ATP 23. Compare and contrast the following pairs of terms: anaerobic and aerobic respiration. without oxygen and with oxygen 24. List the stages of cellular respiration and indicate whether each is anaerobic or aerobic. glycolysis: anaerobic; Krebs cycle (citric acid cycle) aerobic; electron transport chain (ETC) aerobic 2 25. Draw a simple sketch of a mitochondrion. Label the following: outer membrane, inner membrane, cristae and matrix. Indicate on your drawing where each stage of respiration (glycolysis, Krebs cycle, electron transport chain) occurs. Include the cytoplasm that surrounds the mitochondria in your drawing. (8 points) outer mem. matrix (K.C. inner mem. (ETC) cristae glycolysis (cytoplasm) b 26. ________ The first step in releasing the energy that is stored in molecules of glucose is known as: (a) fermentation (b) glycolysis (c) the bridge reactions (d) electron transport (e) aerobic respiration. True 27. ________ True or False. Even though cellular respiration is an energy releasing process, the cell must invest a small amount of energy to get the reaction going. false 28. ________ True or False. The hydrogen electron acceptor during glycolysis is FAD. NAD+ 29. The diagram to the right shows the steps of glycolysis. Fill in the empty boxes of this diagram. (3 pts) glucose glucose ____________________ Glycolysis begins with what 6carbon molecule? 31. ____________________ What 3-carbon molecules are pyruvic acid produced at the end of glycolysis? 32. ________ The number of ATP used during glycolysis? 2 2 ATP 30. 2 ADP PGAL NAD+ 4 ADP 4 33. ________ The number of ATP produced during glycolysis? 4 ATP NADH 2 34. ________ The net gain of ATP during glycolysis? 35. What is the purpose of the electron acceptor, NAD+ ? pyruvic acid remain in the cytoplasm for fermentation enter into the mitochondrion for cellular respiration to carry two electrons and a hydrogen ion to the electron transport chain 36. If the level of ATP gets too high in the cell, the enzymes that catalyze the reactions of glycolysis are inhibited. a) Explain why this feedback loop is beneficial for the cell. 3 b) What will happen to the ATP level if glycolysis is inhibited? c) What do you think will happen when the ATP level drops to levels that are too low? 37. List two advantages of glycolysis. (2 points) 1) glycolysis is fast; can produce 1000's of ATP in a second 2) does not require oxygen 38. What is the disadvantage of glycolysis? A cell will quickly run out of NAD+ to accept hydrogen electrons which would cause glycolysis to stop 39. Fill in the diagram to the right showing the possible paths available for the product of glycolysis. The hexagon at the top represents organic compounds or glucose. Place the word glucose in the hexagon at the (1 pt) top. The first oval circle represents the first stage of cellular respiration. Write the name of this stage in the first oval circle. (1 pt) glucose What end product is produced during this first stage? Add this product name to the first oval circle. ( 1 pt) What will happen to the end product of the first stage of respiration? These two possibilities are determined by what molecule? (3 pts) 1) no oxygen: fermentation 2) oxygen present: a. respiration glycolysis (pyruvic acid) O2 absent anaerobic fermentation ATP O2 present aerobic resp. (Krebs C, ETC) Complete the rest of the diagram showing these two ATP possibilities. mitochondria 40. false, _________________ True or False. The aerobic stages of respiration take place in the chloroplasts of the cell. true 41. _________________ True or False. The aerobic stages of respiration take place in the mitochondria of the cell. all organisms 42. False_________________ True or False. Only eukaryotic cells can carry out cellular respiration. 4 43. matrix ____________________ In what part of the mitochondria does the Krebs cycle occur? 44. inner membrane ____________________ Where in the mitochondria does the electron transport chain take place? 45. cristae ____________________ Loops and folds of the inner mitochondrial membrane are called? 46. The diagram to the right shows the chemical reaction sometimes referred to as the “bridge reaction.” Think about what compound starts this reaction. Place the name of this compound in the box at the top of (1 pt) the diagram. Complete the remainder of the diagram. (7 pts) pyruvic acid 2 47. ______ How many times does this bridge reaction occur per molecule of glucose entering cellular respiration? 2 48. ______ The number of NADH produced per molecule of glucose during this reaction? NAD+ CO2 NADH 49. What is the role of Coenzyme A (CoA)? acetate binds to the acetate molecule turning it into Acetyl-CoA. This new molecule will be used in the Krebs cycle CoA Acetyl-CoA 50. The following sentence describes a broad overview of the Krebs cycle. Fill in the blanks of this sentence: Coenzyme A (CoA) attaches the 2-carbon acetate ______________ to the 4-carbon oxaloacetic acid citric acid ________________________ to form the 6-carbon _________________. (3 pts) to the Krebs cycle d 51. ________ Before the Krebs cycle can proceed, pyruvic acid must be converted to: (a) lactic acid (b) oxaloacetic acid (c) citric acid (d) acetyl CoA (e) NADH 5 52. The diagram to the right shows the chemical reactions that occur during the Krebs cycle. Complete the diagram. (5 pts) CoA citric acid Co2 NAD+ 53. For each turn of the Krebs cycle: NADH 1 ____ a) How many ATP are produced? 3 ____ b) How many NADH are produced? oxaloacetic acid 5-carbon compound CO2 NAD+ 1 ____ c) How many FADH 2 are produced? 2 ____ d) How many molecules of carbon dioxide are produced? 54. For each molecule of glucose entering respiration: NADH NADH NAD+ ADP ATP 4-carbon compound 2 ____ a) How many ATP are produced during the Krebs cycle? 6 ____ b) How many NADH are produced during the Krebs cycle? 4-carbon compound FADH2 FAD 2 c) How many FADH 2 are produced during the Krebs cycle? ____ 4 d) How many molecules of carbon dioxide are produced during the Krebs cycle?? ____ 55. 56. 57. NADH and FADH2 ___________________ What molecules are made during the Krebs cycle and are later used in the electron transport chain? oxygen ___________________ What molecule determines whether pyruvic acid will undergo fermentation or be sent to the Krebs cycle? A __________ Which of the following is not a product of the Krebs cycle? (a) acetate (b) carbon dioxide (c) NADH (d) FADH2 (e) citric acid (f) oxaloacetic acid 58. How will the NADH and the FADH 2 be used? Used to release hydrogen atoms to create a concentration gradient to produce ATP 59. What will happen to the carbon dioxide that has been produced during respiration? released from the cell 6 60. Diagram of the electron transport chain inter-membrane space high proton concentration eeeATP synthase Inner membrane (cristae) 2 FADH2 O2 10 NADH H2 O ADP + P ATP low proton concentration mitochondrial matrix a) b) c) d) e) f) g) h) i) Label the following on the diagram above: mitochondrial matrix, inner membrane, inner membrane space, cristae. (4 pts) Using the symbol, e _, show the path of electrons from their entry point to their final destination. (2 pt) Label the place where 10 NADH enter the electron transport chain. Label the place where 2 FADH 2 enter the electron transport chain. What is the final electron acceptor? Label the final electron acceptor and the product it produces. (2 pt) Indicate the direction of movement of hydrogen protons. Label the area of high hydrogen proton concentration. Label the area of low hydrogen proton concentration. (3 pt) There is only one place that is permeable to the re-entry of hydrogen protons. Label this on the drawing. What is the name of this re-entry protein? (1 pt) What happens as hydrogen protons flow from the area of high concentration to the area of low concentration? Indicate this on the diagram above. (1 pt) What is the end result of all of this? Label this in the drawing above. (3 pts) 61. _____________________ True or False. At the end of the electron transport chain, hydrogen combines with carbon dioxide to form water. true 62. _____________________ True or False. The electron transport chain consists of a series of proteins that are embedded in the inner membrane. 63. As high-energy electrons flow down the electron transport chain, energy is released. What is this energy used to do? Pump hydrogen ions (protons) from the matrix into the inter membrane space 64. How are ATP produced during this final stage of respiration? using the ATP synthase 65. How is the production of ATP in the electron transport chain similar to the production of ATP during the light dependent reactions of photosynthesis? 7 65. 1) Both pass high energy electrons from one protein to another protein 2) The energy from these electrons is used to pump hydrogen ions against their concentration gradient 3) the hydrogen ions eventually flow through an ATP synthase, causing it to create ATP (3 pts) 66. Let’s summarize the production of ATP (per glucose molecule) during cellular respiration: 2 _______ a) How many ATP are gained during glycolysis? 0 _______ b) How many ATP are produced during the bridge reactions? 2 _______ c) How many ATP are produced during the Krebs cycle? 34 _______ d) How many ATP are produced during the electron transport chain? 3 _______ e) How many ATP can be produced for each NADH? 2 _______ f) How many ATP can be produced for each FADH 2? 2 _______ g) How many ATP are gained during anaerobic respiration? 36 or 38 h) How many ATP are produced in aerobic respiration? _______ 2 _______ i) 36 _______ j) How many ATP are produced in the cytoplasm? How many ATP are produced in the mitochondria? 67. What condition must exist in a cell that would cause the cell to enter into fermentation? low oxygen levels pyruvic acid 68. ______________________ This molecule is made during glycolysis and used in the later steps of fermentation. (2 pts) alcoholic fermentation 69. ______________________ List the two types of fermentation. lactic acid fermentation ______________________ yeast 70. ______________________ What organism is used to carry out alcoholic fermentation for commercial purposes? ethyl alcohol 71. ______________________ During alcoholic fermentation, pyruvic acid is converted into what compound? 2 72. ___________ How many ATP are gained per molecule of glucose during fermentation? 73. How is alcoholic fermentation used in the baking industries? make bread by releasing CO2 causing the bread to rise 8 74. What causes your muscles to become tired and sometimes cramp during periods of strenuous exercise? Lactic acid builds up in your muscle cells and decreases the pH causing severe cramps (1 pt) (1pt) e 75. _________ The anaerobic pathways provide enough energy to meet the energy needs of which of the following? (a) all living organisms (b) unicellular organisms and almost all of the multicellular organisms (c) only photosynthetic organisms (d) no organisms (e) all unicellular organisms. 76. Write equations to show how alcoholic fermentation compares to lactic acid fermentation. alcoholic fermentation glucose ==> pyruvic acid + NADH ==> ethyl alcohol + carbon dioxide + NAD+ (1 pt) (1 pt) lactic acid fermentation glucose ==> pyruvic acid + NADH ==> lactic acid + NAD+ (1 pt) (1 pt) 9