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1. In the early 1900s, many children had a disease called rickets. Research showed that the children had a deficiency of a vitamin that is necessary for the proper formation of bones. Which vitamin was lacking in the diets of these children__________________________________________________________________ 2. Use the information and the diagram below to answer the following item. Catalase is an enzyme found in the tissues of plants and animals, including humans. Catalase helps prevent a toxic buildup of hydrogen peroxide in cells by breaking it down into water and oxygen gas. Several students conduct an experiment to test the effects of pH on the activity of catalase. Each test tube contains a solution of hydrogen peroxide and water at various pH levels. The liver tissue is a source of catalase. The diagram below represents the results of their experiment. Based on the students’ results, catalase works best at a pH of _________________________________ 3. What are the building blocks of catalase?______________________________________________________ 4. What element makes up the structure of both DNA and RNA? _____________________________________ 5. Water dissolves many substances. This occurs because water is ____________________________________ 6. What are the characteristics of a carbohydrate? ________________________________________________ __________________________________________________________________________________________ 7. Fluoride is added to drinking water supplies in many states. People cannot see fluoride in the water because it __________________________________ to form a colorless solution. 8. Use the diagram below to answer the following item. What is the name of the structure at #4 _________________________________________________ 1 9. Use the diagram below to answer the following: Which structure is a sugar? _________________________________ Which structure is a phosphate group? ________________________ What does the A stand for? _________________________________ What does the T stand for? _________________________________ What does the G stand for? _________________________________ What does the C stand for? _________________________________ 10. A researcher is testing the effect of acid rain on living organisms. She takes a tissue sample and places it in acid rainwater, which decreases its pH. As the pH decreases, what will most likely happen to the enzyme reaction rates in the cells of this tissue? _________________________________________________________ __________________________________________________________________________________________ 11. Some adult insects are unable to swim but are able to walk on top of water. What characteristic of water enables these insects to walk on top of water? __________________________________________________________________________________________ 12. Glucose is a building block of carbohydrates. What type of a carbohydrate would best describe glucose? __________________________________________________________________________________________ 13. A scientist believes that a factory has been dumping acid into a local river. To test this hypothesis, which property of water should the scientist monitor? ____________________________________________________________________________________________ 2 14. Use the information and the graph below to answer the following questions. Catalase is an enzyme found in plant and animal cells. Hydrogen peroxide is a harmful substance found in cells. Catalase causes hydrogen peroxide to break down into water and oxygen. A student conducted an experiment to determine whether plant and animal cells have the same amount of catalase. She used liver and potato tissues in the experiment. The student followed the procedures below. 1. Label two identical test tubes, 1 and 2. 2. Pour 10 milliliters of hydrogen peroxide solution (1% concentration) into each test tube. 3. Add a small piece of liver tissue to Test Tube 1. 4. Add a small piece of potato tissue to Test Tube 2. 5. Collect the oxygen released from each test tube for 25 seconds. 6. Measure and record the volume of oxygen for each test tube. The graph below shows the results from the experiment. What type of molecule is catalase? _______________________________________________________________ 15. Use the information and graph above to answer the following question. The student conducted a second experiment. She boiled the liver tissue completely and added it to the hydrogen peroxide solution. She observed that little to no oxygen was released in the second experiment. Which of these statements best supports the student’s observations? 1. Exposing catalase to high temperatures makes it inactive. 2. Exposing catalase to high temperatures changes it into a different enzyme. 3. Boiling liver breaks down hydrogen peroxide faster. 4. Boiling removes oxygen from the liver. 16. Which of these correctly matches the molecule with its function? 1. lipid—stores genetic information 3. enzyme—speeds up chemical reactions 2. vitamin—supplies energy to cells 4. carbohydrate—manufactures cell membranes 17. Most carbohydrates in the human body are used for ____________________________________________ 18. A scientist removed the cell membranes from bacteria cells in a culture. She analyzed the cell membranes for specific molecules. What macromolecule was probably the most common type of molecule present in the bacteria cell membranes? _____________________________________________________________________ 19. What is the name of the repeating units that form a DNA molecule? _______________________________ 3 20. Cells in the stomach produce pepsin, an enzyme, to help digest food. Pepsin works best at a pH of 2. Which of these graphs most likely shows what will happen to the activity of pepsin as the pH of the stomach is increased? C A D B 21. Amylase is an enzyme that allows the human body to digest starch. Which of these diagrams best represents part of the structure of amylase? A. C. D. B. 22. What is the major role of lipids within a cell? __________________________________________________ 23. A dog gets many nutrients from its food including amino acids. Which of these can be built directly using the amino acids? ___________________________________________________________________________ 4 24. A biologist is using a microscope to observe a very small organism with the low-power 10X lens. If the biologist switches to the 40X lens, how many times larger will the organism appear? _____________________ 25. The table below compares the size of a bacterium and a virus. How many times larger is the bacterium than the virus? _________________________________________________________ 26. The diagram below shows an animal cell in a beaker containing a solution of sugar and water. The cell membrane is permeable only to water. Which statement describes the relationship between the animal cell and the contents of the beaker? A .There is a higher concentration of water inside the cell than outside the cell. B. There is a higher concentration of sugar inside the cell than outside the cell. C. There is an equal concentration of water inside the cell as outside the cell. D. There is an equal concentration of sugar inside the cell as outside the cell. 27. Several students are conducting an experiment to test the effect of exercise on heart rate. Students do 20 sit-ups in one minute of exercise. The data chart below shows the heart rate at one-minute intervals for each student. Which of these is the dependent variable? A. time B. heart rate C. type of exercise D. number of sit-ups 5 28. The students decide to ignore any results that were too far above or below their prediction. They repeat these trials until a value closer to their prediction is obtained. The students’ decision to ignore data and repeat trials affects the experiment by A. introducing bias B. decreasing controls C. increasing accuracy D. eliminating variables 29. Scientists estimate that dental plaque contains up to 1x1011 bacteria per gram. What number is equal to 1x1011? ________________________________________________________ 30. The chart below is the nutrition facts found on a bag of pretzels. How many pretzels would be in a 100-Calorie serving? ______________________________________________ 31. For a compound to considered organic is must contain __________________________________________ 32. Using the diagram below, which enzyme works best at a neutral pH? _______________________________ 6 33. Osmosis is the movement of _______________________ from __________________ concentration to ___________________________ concentration. 34. Diffusion is the movement of ______________________ from _________________ concentration to __________________________ concentration. 35. When a cell is placed in a hypertonic solution it will _________________ because ___________________. 36. Active transport uses ___________________, passive transport uses no ________________, and facilitated diffusion is a form of _______________________ transport. 37. The graphs show the effects of temperature and pH on the reaction rate of an enzyme. Food will stay fresh longer when enzyme activity is slowed. Which of the following conditions would most likely slow enzyme activity? A. reducing pH from 8 to 7 by adding a weak acid B. increasing pH from 5 to 6 by adding a weak base C. reducing temperature from 30°C to 20°C by refrigeration D. increasing temperature from 30°C to 40°C by heating 38. Vitamins have important functions in the human body and are necessary for maintaining good health. Which vitamin is necessary for blood clots to form? _____________________________________________ 39. Name 2 factors that can denature a protein ___________________________________________________ __________________________________________________________________________________________ 40. Many proteins act as _______________________________or biological catalysts. 7