BIO101 Unit 2 Test Questions with Correct Answers

BIO101 Unit 2 Test Questions with Correct Answers If there are twelve different intermediate products produced during production of a molecule in a cell, we can expect that there a. is one enzyme that carries this process through all twelve stages to the end product. b. are about twelve enzymes, at least one responsible for each step in the metabolic pathway. c. is one enzyme for degradation and another enzyme for synthesis. d. there may not be any enzymes involved if this is a natural cell product. e. must be twelve different raw materials combined in the cell by one enzyme. - Answer- are about twelve enzymes, at least one responsible for each step in the metabolic pathway Two molecules of glucose combine to form a disaccharide molecule during a(n) reaction. a. dehydration b. hydrolysis c. hydrogen bond d. ionic bond e. inert - Answer-dehydration Which is true about energy of activation? a. Energy of activation is measured as the energy that is released after a reaction occurs. b. Adding the correct enzyme can lower the energy of activation. c. In any one metabolic pathway, all steps will have the same energy of activation. d. Energy of activation is the difference between the energy of the reactant and the energy of the product. e. The energy of activation is always lower than the energy of the reactant. - Answer- Adding the correct enzyme can lower the energy of activation The change in free energy of a reaction, delta G, is calculated by a. subtracting the free energy content of the products from that of the reactants. b. subtracting the free energy content of the reactants from that of the products. c. adding the free energy content of the products to that of the reactants. d. the amount of free energy content of the reactants. e. the amount of free energy content of the products. - Answer-subtracting the free energy content of the reactants from that of the products An early experiment by Van Helmont (1600s) describes how he grew a tree in a large pot and found that after five years, the amount of soil in the pot had not changed. He concluded that the increase in weight was due to the addition of water. At that time, the compounds of the air had not yet been identified. Today, it is known that he only discovered half the story. Which of these experiments would NOT provide evidence that materials from a source other than water were involved in photosynthesis? a. Carbon is discovered as a major element in trees and is lacking in water molecules. b. Radioactive carbon in carbon dioxide in the air is identified as part of tree structures. c. A very careful analysis of the water taken in and lost by the tree would have revealed only part of the added weight gained by the tree. d. After adding radioactive water with labeled oxygen to a plant, radioactive oxygen is given off. e. Radio - Answer-After adding radioactive water with labeled oxygen to a plant, radioactive oxygen is given off To measure the activity of the human brain during certain thought processes, a short- lived radioactive sugar is injected in the carotid artery and is utilized by those cells that are most active. This shows up on a PET scan and demonstrates the detection of a. ionic bonds. b. high levels of radiation. c. covalent bonds. d. neutrons. e. isotopes. - Answer-isotopes Which type of bond formation is responsible for the properties of water? a. hydrogen b. polar covalent c. ionic d. nonpolar covalent e. None of these bonds play a role in the properties of water. - Answer-hydrogen How many NADH + H+ are produced by the citric acid cycle per turn? a. one b. two c. three d. four e. six - Answer-three Which statement about photosynthesis and cellular respiration is true? a. Photosynthesis produces water while cellular respiration uses water. b. Photosynthesis produces oxygen while cellular respiration uses oxygen. c. Photosynthesis occurs in mitochondria while cellular respiration occurs in chloroplasts. d. Photosynthesis breaks down carbohydrates while cellular respiration produces carbohydrates. e. Photosynthesis requires oxygen while cellular respiration requires sunlight. - Answer- Photosynthesis produces oxygen while cellular respiration uses oxygen Heterotrophs a. have the ability to synthesize organic molecules from inorganic molecules. b. are ultimately dependent upon preformed organic molecules made by producers. c. are the origin of all food for the rest of the living world. d. are also called autotrophs. e. None of these features are characteristic of heterotrophs. - Answer-are ultimately dependent upon preformed organic molecules made by producers Water is split and oxygen is released in a. the electron transport chain. b. the cyclic electron pathway. c. the Calvin cycle reactions. d. the noncyclic electron pathway. e. photosystem I. - Answer-the noncyclic electron pathway Which molecules are the reactants or substrates for aerobic respiration? a. glucose and carbon dioxide b. lactate and oxygen c. carbon dioxide and water d. oxygen and glucose e. glucose and water - Answer-oxygen and glucose