Name: ________________________ Class: ___________________ Date: __________ ID: P

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Chapter 2 Exam

Multiple ChoiceIdentify the choice that best completes the statement or answers the question.

____ 1. The electrons of an atoma. are found in the nucleus along with the protons.b. occupy the space surrounding the nucleus.c. are attached to the positive charge of neutrons.d. have a positive charge.

____ 2. The shape of a protein is primarily determined bya. the type and sequence of its amino acids.b. its cell location.c. its size.d. None of the above

____ 3. Which statement correctly describes how carbons’s ability to form four bonds makes it uniquely suited to form macromolecules?a. It forms short, simple carbon chains c. It forms covalent bonds with other

carbon atoms.b. It forms covalent bonds that can exist in a

single plane. d. it forms large, complex, diverse

molecules

____ 4. Carbohydrates and proteins are two types of macromolecules. Which functional characteristic of proteins distringuishes them from carbohydrates?a. efficient storage of usable chemical

energyc. ability to catalyze biochemical reactions

b. large amount of stored information d. tendency to make cell membrances hydrophobic

____ 5. Hydrogen ions, H+, react with hydroxide ions, OH, to forma. an acid. c. water.b. a base. d. None of the above

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Base your answers to questions __ and __ on the graph below and on your knowledge ofbiology.

____ 6. Pepsin works best in which type of environment?a. neutral c. basic, onlyb. acidic, only d. sometimes acidic, sometimes basic

____ 7. Neither enzyme works at a pH ofa. 3 c. 13b. 1 d. 5

____ 8. Long chains of amino acids are found ina. lipids. c. sugars.b. proteins. d. carbohydrates.

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____ 9. What substance could be represented by the letter X in the diagram below?

a. carbon dioxide c. carbohydratesb. ozone d. water

____ 10. When organisms break the bonds of organic compounds, the organisms cana. use the energy obtained to digest molecules produced by respiration that uses oxygenb. use the smaller molecules to plug the gaps in the cell membrane to slow diffusionc. excrete smaller amounts of solid waste materials during vigorous exercised. obtain energy or reassemble the resulting materials to form different compounds

____ 11. An enzymea. is not used up when catalyzing a reaction.b. lowers the activation energy of a reaction.c. bonds with a substrate molecule at the enzyme’s active site.d. All of the above

____ 12. Sharing of electrons in the outer energy levels of two atomsa. is found only among carbon atoms.b. only occurs if both are atoms of the same element.c. occurs in covalent bonds.d. results in ion formation.

____ 13. Water is important to life because ita. influences the shape of the cell membrane.b. surrounds all cells.c. is found inside cells.d. All of the above

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____ 14. Refer to the illustration above. Reaction 3 in the grapha. requires more activation energy than Reaction 2.b. is the same as Reaction 1, but faster.c. is slower than Reaction 2.d. probably occurred in the presence of a catalyst.

____ 15. Refer to the illustration above. Which of the following statements regarding the graph is true?a. Reaction 2 occurs faster than Reaction 3 because Reaction 2 requires more energy than

Reaction 3.b. Reactant A contains more energy at the beginning of the reaction than product C has after

the reaction.c. The difference between the graphs shown for Reaction 2 and Reaction 3 is because of a

difference in the activation energy of these reactions.d. All of the above

____ 16. An enzyme and four different molecules are shown in the diagram below.

The enzyme would most likely affect reactions involvinga. molecules A and Cb. molecule A, onlyc. molecule C, onlyd. molecules B and D

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____ 17. The diagram below shows a portion of a graduated cylinder.

What is the volume of the liquid in this cylinder?a. 22 mL c. 25 mLb. 24 mL d. 26 mL

____ 18. The graph below shows the effect of temperature on the relative rate of action of enzyme X on a protein.

Which change would not affect the relative rate of action of enzyme X?a. the removal of the protein when the reaction is at 30°Cb. a decrease in temperature from 40°C to 10°Cc. the addition of cold water when the reaction is at 50°Cd. an increase in temperature from 70°C to 80°C

____ 19. Polysaccharides area. unsaturated fats. c. proteins.b. lipids. d. carbohydrates.

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____ 20. A substance that is composed of only one type of atom is called a(n)a. nucleus. c. element.b. cell. d. molecule.

____ 21. Lipids area. nonpolar molecules. c. water soluble.b. polar molecules. d. similar to water molecules.

____ 22. All of the following are examples of lipids excepta. starch. c. earwax.b. cholesterol. d. saturated fats.

____ 23. Carbohydrates and lipids have many carbon-hydrogen bonds; therefore, they botha. are easily dissolved in water. c. dissolve only in vinegar.b. store energy in these bonds. d. exist only in cells of plants.

____ 24. A scientist observes that, when the pH of the environment surrounding an enzyme is changed, the rate the enzyme catalyzes a reaction greatly decreases. Which statement best describes how a change in pH can affect an enzyme?a. A pH change can cause the enzyme to

change its shape.c. A pH change can add new molecules to

the structure of the enzyme.b. A pH change can remove energy

necessary to activate an enzymed. A pH change can cause an enzyme to

react with a different substrate.

____ 25. Substance A is converted to substance B in a metabolic reaction. Which statement best describes the role of an enzyme during this reaction?a. It provides energy to carry out the

reaction. c. It speeds up the reaction without being

consumed. b. It adjusts the pH of the reaction medium. d. It dissolves substance A in the reaction

medium

____ 26. Which of the following is not an organic macromolecule?a. carbohydrate c. nucleic acidb. ice d. lipid

____ 27. A molecule that has a partial positive charge on one side and a partial negative charge on the other side is called aa. nonpolar molecule. c. bipolar molecule.b. polar molecule. d. charged molecule.

____ 28. Ionic bonds form between molecules that havea. the same charge. c. no charges.b. opposite charges. d. neutral charges.

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____ 29. The graph below illustrates the relative amounts of product formed by the action of an enzyme in a solution withe a pH of 6 at seven different temperatures.

Which statement best expresses the amount of product that will be formed at each temperature if the experiment is repeated at a pH of 4?a. The amount of product formed will be less than that produced at pH 6.b. The amount of product formed will be equal to that produced at pH 6.c. The amount of product formed can not be accurately predicted.d. The amount of product formed will be greater than that produced at pH 6.

Molecule A Molecule B

____ 30. Refer to the illustration above. Molecules like Molecule B are found ina. proteins. c. nucleic acids.b. lipids. d. carbohydrates.

____ 31. Which of the following organic molecules are classified as carbohydrates?a. nucleotides c. amino acidsb. sugars d. fatty acids

____ 32. All organic compounds contain the elementa. calcium. c. nitrogen.b. sodium. d. carbon.

____ 33. The smallest particle of matter that can retain the chemical properties of carbon is a(n)a. element. c. carbon atom.b. carbon macromolecule. d. carbon molecule.

____ 34. The molecule on which an enzyme acts is called a(n)a. organic molecule. c. active site.b. substrate. d. inactive site.

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____ 35. All matter is composed ofa. carbon. c. molecules.b. cells. d. atoms.

____ 36. Water is a polar molecule becausea. it contains two hydrogen atoms for each oxygen atom.b. it has a charge.c. different parts of the molecule have slightly different charges.d. it does not have a charge.

____ 37. When placed in the same container, oil and water do not mix becausea. water is polar and oil is nonpolar. c. they are both nonpolar.b. water is nonpolar and oil is polar. d. they are both polar.

____ 38. ATP (adenosine triphosphate) stores energy for cells to use in the bonds between itsa. phosphates. c. carbon atoms.b. nucleotides. d. amino acids.

____ 39. Which statement best describes an effect of the low density of frozen water in a lake? a. When water in a lake freezes, it floats,

providing insulation for organisms below.

c. Water removes thermal energy from the land around a lake, causing the lake to freeze.

b. When water freezes, it contracts, decreasing the water level in a lake.

d. Water in a lake freezes from the bottom up, killing most of the aquaitc organisms.

____ 40. Which statement concerning simple sugars and amino acids is correct?a. They are both stored as fat molecules in the liver.b. They are both needed for the synthesis of larger molecules.c. They are both building blocks of starch.d. They are both wastes resulting from protein synthesis.

____ 41. The two types of nucleic acids area. lipids and sugars. c. chlorophyll and retinal.b. DNA and RNA. d. glucose and glycogen.

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Base your answers to questions 48 through 50 on the passage below and on your knowledgeof biology.Great Effects on the Great Lakes due to Global Warming Trees such as the jack pine, yellow birch, red pine, and white pine may no longer be able to grow in the Great Lakes region because summers are becoming warmer. However, other trees such as black walnut and black cherry may grow in the area, given enough time. The change in weather would favor these new tree species. The Great Lakes region is the only place in the world where the endangered Kirtland’s Warbler breeds. This bird species nests in young jack pine trees (5 to 23 years old). The vegetation must have specific characteristics or the birds will not nest. A specific area of Michigan is one of the few preferred areas. If the jack pines can no longer grow in this area, the consequences for the Kirtland’s Warbler could be devastating. Recent research findings also suggest that algae production in Lake Ontario and several other Great Lakes will be affected as warmer weather leads to warmer lake water. An increase in water temperature reduces the ability of water to hold dissolved oxygen. These changes have implications for the entire Great Lakes food web. Changes in deep-water oxygen levels and other habitat changes may prevent the more sensitive cold-water fish from occupying their preferred niches in a warmer climate. All other factors being equal, climatic changes may not have a negative effect on every species in the Great Lakes region. This is because the length of the growing season would be increased. Some temperaturesensitive fish could move to cooler, deeper water when the surface water temperatures become too high. The total impact of global warming is difficult to predict.

____ 42. Which graph best shows the relationship between changes in temperature in the Great Lakes waters and the amount of dissolved oxygen those waters can hold?

a. 3 c. 1b. 2 d. 4

____ 43. Due to the polarity of water, compounds that dissolve best in water containa. nonpolar bonds. c. polar bonds.b. ionic bonds. d. Both (b) and (c)

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CompletionComplete each statement.

Base your answers to questions 50 and 51 on the information and graph below and onyour knowledge of biology.

44. State how the pH of these Adirondack lakes changed between 1880 and 1980.

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45. State the effect that the pH change in these Adirondack lakes had on lake trout, browntrout, smallmouth bass, and mussels.

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Essay

46. Proteins are a major part of every living cell and have many different functions within each cell. Carbohydrates also perform numerous roles in living things.

Part A: Describe how the structures of proteins are different to the structures of carbohydrates.

Part B: Describe how the structures of proteins are similar to the structures of carbohydrates.

Part C: Describe how the functions of proteins differ from the functions of carbohydrates.

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Chapter 2 ExamAnswer Section

MULTIPLE CHOICE

1. ANS: B PTS: 1 DIF: I OBJ: 2.1.1 2. ANS: A PTS: 1 DIF: II OBJ: 2.3.2 3. ANS: D PTS: 1 4. ANS: C PTS: 1 5. ANS: C PTS: 1 DIF: I OBJ: 2.2.3 6. ANS: B PTS: 1 DIF: 1 REF: P

OBJ: 1 7. ANS: C PTS: 1 DIF: 1 REF: P

OBJ: 1 8. ANS: B PTS: 1 DIF: I OBJ: 2.3.2 9. ANS: C PTS: 1 DIF: 1 REF: CH

OBJ: 1 10. ANS: D PTS: 1 DIF: 2 REF: P | CH

OBJ: 1 11. ANS: D PTS: 1 DIF: I OBJ: 2.4.3 12. ANS: C PTS: 1 DIF: II OBJ: 2.1.3 13. ANS: D PTS: 1 DIF: I OBJ: 2.2.1 14. ANS: D PTS: 1 DIF: III OBJ: 2.4.2 15. ANS: C PTS: 1 DIF: III OBJ: 2.4.2 16. ANS: C PTS: 1 DIF: 3 REF: CH

OBJ: 1 NOT: I am not 100% I have this right. I say that it is d because if A bound to C then it could change the shape of C, thus also affecting the enzyme because the molecule couldn't bind to it in that form. Right?.........................................I think the answer is b. I don't see how A could bind to C.--JKOJr

17. ANS: B PTS: 1 DIF: 1 REF: POBJ: 1

18. ANS: D PTS: 1 DIF: 2 REF: P | CHOBJ: 1

19. ANS: D PTS: 1 DIF: I OBJ: 2.3.2 20. ANS: C PTS: 1 DIF: I OBJ: 2.1.1 21. ANS: A PTS: 1 DIF: I OBJ: 2.3.2 22. ANS: A PTS: 1 DIF: I OBJ: 2.3.2 23. ANS: B PTS: 1 DIF: I OBJ: 2.3.2 24. ANS: A PTS: 1 25. ANS: C PTS: 1 26. ANS: B PTS: 1 DIF: I OBJ: 2.3.1 27. ANS: B PTS: 1 DIF: I OBJ: 2.1.2 28. ANS: B PTS: 1 DIF: I OBJ: 2.1.3 29. ANS: C PTS: 1 DIF: 1 REF: P | CH

OBJ: 1 30. ANS: B PTS: 1 DIF: II OBJ: 2.3.2

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31. ANS: B PTS: 1 DIF: I OBJ: 2.3.2 32. ANS: D PTS: 1 DIF: I OBJ: 2.3.1 33. ANS: C PTS: 1 DIF: I OBJ: 2.1.1 34. ANS: B PTS: 1 DIF: I OBJ: 2.4.3 35. ANS: D PTS: 1 DIF: I OBJ: 2.1.1 36. ANS: C PTS: 1 DIF: II OBJ: 2.2.2 37. ANS: A PTS: 1 DIF: I OBJ: 2.2.2 38. ANS: A PTS: 1 DIF: II OBJ: 2.3.4 39. ANS: A PTS: 1 40. ANS: B PTS: 1 DIF: 1 REF: CH

OBJ: 1 41. ANS: B PTS: 1 DIF: I OBJ: 2.3.3 42. ANS: D PTS: 1 DIF: 2 REF: P | E

OBJ: 8a 43. ANS: D PTS: 1 DIF: I OBJ: 2.2.2

COMPLETION

44. ANS: The pH decreased and the lakes became more acidic.

PTS: 1 DIF: 2 REF: P | En OBJ: 1 | 8b 45. ANS: The survival rate of all species decreased.

PTS: 1 DIF: 2 REF: P | En OBJ: 1 | 8b

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ESSAY

46. ANS: Part A: Proteins are polymers of amino acids joined together by peptide bonds. There are 20 different amino acids that make up essentially all proteins on earth. Each of these amino acids has a fundamental design composed of a central carbon (also called the alpha carbon) bonded to: a hydrogen a carboxyl group an amino group a unique side chain or R-group

Part B: Carbohydrates composed mostly of the elements carbon (C), hydrogen (H), and oxygen (O). The smallest carbohydrates are the simple sugars, also known as monosaccharides and disaccharides, meaning that they are made up of one or two sugar molecules. The larger carbohydrates are made up of these smaller simple sugars and are known as polysaccharides (many sugar molecules) or complex carbohydrates. These are usually made up of many linked glucose molecules Proteins are composed of the elements carbon (C), oxygen (O), hydrogen (H), and nitrogen (n). Proteins are formed by the linking of different combinations of the twenty common amino acids. The structure of proteins is often distinguished into four levels.These are called primary, secondary, tertiary, and quaternary structure.

Part C: Proteins are essential to growth and repair of muscle and other body tissues. Carbohydrates are our main source of energy

PTS: 1