Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Microbial metabolism wikipedia , lookup
Enzyme inhibitor wikipedia , lookup
Light-dependent reactions wikipedia , lookup
Isotopic labeling wikipedia , lookup
Photosynthesis wikipedia , lookup
Biosynthesis wikipedia , lookup
Metalloprotein wikipedia , lookup
Oxidative phosphorylation wikipedia , lookup
Photosynthetic reaction centre wikipedia , lookup
Biochemistry wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Biology TEST: Chapter 2 The Chemistry of Life (Form: mrk 2008) Do not write on this test form. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. Darken your choice on the Scantron answer sheet. ____ ____ ____ ____ ____ ____ ____ ____ 1. The three particles that make up an atom are a. protons, neutrons, and isotopes. b. neutrons, isotopes, and electrons. c. positives, negatives, and electrons. d. protons, neutrons, and electrons. 2. Isotopes are atoms of the same element with the same number of protons and a. a different number of electrons. b. a different number of molecules. c. a different number of neutrons. d. the same number of neutrons. 3. Which of the following is a use of radioactive isotopes? a. can determine the ages of rocks and fossils b. can be used to treat cancer and kill bacteria that cause food to spoil c. used as “tracers” to follow the movements of substances within organisms d. all of the above 4. Which of the following terms describes a substance formed by the combination of two or more elements in definite proportions? a. compound b. isotope c. nucleus d. enzyme 5. A covalent bond is formed as the result of a. transferring electrons. b. sharing an electron pair. c. transferring protons. d. sharing a proton pair. 6. What type of electron is available to form bonds? a. valence b. nucleus c. ionic d. covalent 7. What type of ion forms when an atom loses electrons? a. neutral b. positive c. negative d. possibly positive or negative 8. The most abundant compound in most living things is a. carbon dioxide. b. water. c. sodium chloride. d. sugar. ____ ____ ____ ____ ____ ____ ____ ____ ____ ____ 9. Water molecules are polar, with the a. oxygen side being slightly positive and the hydrogen side being slightly negative. b. oxygen and hydrogen sides being slightly positive. c. oxygen and hydrogen sides being slightly negative. d. oxygen side being slightly negative and the hydrogen side being slightly positive. 10. Solutions that contain concentrations of H+ ions lower than pure water a. have pH values below 7. b. are acids. c. are bases. d. are enzymes. 11. Amino acid is to protein as a. fat is to lipid. b. DNA is to RNA. c. sugar is to fat. d. simple sugar is to starch. 12. A monosaccharide is a a. carbohydrate. b. lipid. c. nucleic acid. d. protein. 13. Which of the following organic compounds is the main source of energy for living things? a. carbohydrates b. lipids c. nucleic acids d. proteins 14. Which of the following is NOT a function of proteins? a. store and transmit heredity b. help to fight disease c. control the rate of reactions and regulate cell processes d. build tissues such as bone and muscle 15. Which of the following statements about enzymes is NOT true? a. Enzymes work best at a specified pH. b. All enzymes work inside cells. c. Enzymes are proteins. d. Enzymes are organic catalysts. 16. Which of the following statements is true about catalysts? a. Catalysts slow down the rate of chemical reactions. b. All catalysts are enzymes. c. Catalysts are used up during a chemical reaction. d. Catalysts lower the activation energy of a chemical reaction. 17. Enzymes affect the reactions in living cells by changing the a. products of the reaction. b. speed of the reaction. c. temperature of the reaction. d. pH of the reaction. 18. What is the process that changes one set of chemicals into another set of chemicals? a. cohesion b. adhesion c. chemical reaction d. dissolving ____ 19. What is the term used to describe the energy needed to get a reaction started? a. adhesion energy b. activation energy c. cohesion energy d. chemical energy Modified True/False Indicate whether the sentence or statement is true or false. Mark “A” for true or “B” for false on the Scantron answer sheet. ____ 20. Scientists show the composition of compounds by a kind of shorthand known as a chemical formula. ____ 21. When atoms share six electrons, they are joined by a double bond. ____ 22. Adhesion is responsible for the surface of the water in a graduated cylinder that is slightly curved at the sides. ____ 23. When sugar is dissolved in water, the sugar and water are chemically combined. ____ 24. A substance with equal numbers of ions and ions is an alkaline solution. ____ 25. Buffers are weak acids or bases that can react with strong acids or bases to prevent sudden changes in pH. ____ 26. Lipids are important parts of biological membranes and waterproof coverings. ____ 27. Polysaccharides are formed through the process known as polymerization. ____ 28. The substances that are present when a chemical reaction begins are the products. ____ 29. The chemical reaction of and is irreversible. Completion Complete each sentence on this page and the next using the word bank below. If the answer chosen is made up of a letter combination, darken ALL the letters that make up that combination. a. b. c. d. e. acid -ase covalent chemical monomers ab. ac. ad. ae. bc. OH- ions nucleus ionic H+ ions -ose bd. be. cd. ce. de. electrons hydrogen base polarity products 30. Most of the mass of an atom is concentrated in the ____________________. 31. If an atom contains 15 protons, it must contain 15 ____________________. 32. Because they have the same number of protons and electrons, all isotopes of an element have the same ____________________ properties. 33. A chemical bond formed by the transfer of electrons is a(an) ____________________ bond. 34. A water molecule is polar because there is an uneven distribution of electrons between the oxygen and the ____________________ atoms. 35. Water’s ____________________ allows it to dissolve compounds such as table salt (NaCl). 36. The stomach produces a(an) ____________________ to help digest food. 37. The pH scale is a measurement system that indicates the concentration of ____________________ in solution. 38. Complex carbohydrates are to monosaccharides as polymers are to ____________________. 39. The elements or compounds produced by a chemical reaction are known as ____________________. 40. The name of an enzyme usually ends in ____________________. Other USING SCIENCE SKILLS Element Symbol Protons Neutrons Hydrogen H 1 Helium He 2 Carbon C 6 Oxygen O 8 Neon Ne Aluminum Al Zinc Zn Electrons Atomic Number 1 Mass Number 4 6 8 10 10 13 20 27 30 30 65 Figure 2-1 41. Calculating Based on Figure 2-1, what is the mass number of carbon? a. 6 b. 7 c. 8 d. 12 42. Applying Concepts Based on Figure 2-1, what is the atomic number of oxygen? a. 8 b. 16 c. 24 d. not enough information 43. Applying Concepts Using Figure 2-1, how many electrons does an atom of aluminum contain? a. 13 b. 26 c. 27 d. not enough information 44. Applying Concepts According to Figure 2-1, an atom of which element contains two neutrons? a. H b. O c. He d. Al 45. Applying Concepts Based on Figure 2-1, which element has a mass number of 16? a. He b. Al c. H d. O USING SCIENCE SKILLS Figure 2-3 46. Applying Concepts According to Figure 2-3, which enzyme would you expect to find in a bacterium growing in a hot spring? a. Enzyme X b. Enzyme Y c. both X and Y d. neither X nor Y 47. Using Tables and Graphs According to Figure 2-3, at what temperature do the two enzymes have the same amount of activity? a. about 20 º C b. about 35 º C c. about 45 º C d. about 70 º C 48. Using Tables and Graphs According to Figure 2-3, which enzyme has an optimum temperature of 40C? a. Enzyme X b. Enzyme Y c. both X and Y d. neither X nor Y 49. Applying Concepts Based on Figure 2-3, which enzyme would have the most activity in humans? a. Enzyme X b. Enzyme Y c. both X and Y d. neither X nor Y 50. Using Tables and Graphs Based on Figure 2-3, which enzyme is active over the largest temperature range? a. Enzyme X b. Enzyme Y c. both X and Y d. neither X nor Y