AP Biology 2015-2016 Summer Assignment Mrs. Pamela Griffin pgriffin@spotsylvania.k12.va.us Why is there a summer assignment? The first topics of the year are chemistry and biochemistry. If you are a junior or senior, you were taught the majority of this content in chemistry and biology. If you are a sophomore, then you may have learned some of these concepts in middle school. The goal of the summer assignment is to review and/or learn these concepts prior to the first week of school. Reviewing this material over the summer will: 1. Allow us to spend more time on the content with which students are less familiar and did not experience in introductory biology. 2. Require you to practice reading and interpreting the textbook. 3. Allow you to become familiar with the difficulty and design of AP Biology tests. When is the summer assignment due? The summer assignment is due the first day of school, September 8, 2015. No late work will be accepted. What is the actual assignment? The summer assignment covers chapters 2-5 of the text and consists of learning objectives, review assignments, and practice tests. For Chapters 2-5: 1. Review the attached objectives. These are NOT questions for you to answer, but you should use these to guide your reading and use them as a checklist for self assessment. 2. Read each chapter thoroughly. 3. Review the key terms for each chapter. a. It is recommended that you review the terms and their definitions. There is NO specific assignment for the terms this summer. Recommended formats to learn the terms: i. Flash cards (using colored paper/markers and adding pictures or diagrams to your cards can be helpful) ii. Two columns (place concepts on one side and definitions on the other so that the page can be folded over for self quizzing.) iii. Create practice matching tests for the vocabulary words (break the lists into groups of 5-7 terms at once and make sure to answer the tests as well) 4. Complete the attached assignments specific to each chapter. 5. Complete the attached practice tests (you will write on the tests but make sure to also bubble in the scantron sheets provided – make certain each scantron is labeled correctly with the test name). ** The textbook covers greater detail than is necessary for you to know at this point. Therefore it is important for you to focus mainly on the objectives and vocabulary specified by the summer assignment. Just to double check, when is the summer assignment due? The summer assignment is due the first day of school, September 8, 2014. No late work will be accepted. Can I get help over the summer if I do not understand some of the material? I can be contacted through email which I will check approximately once a week: pgriffin@spotsylvania.k12.va.us CHAPTER 2: The Chemical Context of Life Learning Objectives Elements and Compounds 1. Distinguish between an element and a compound. 2. Identify the four elements that make up 96% of living matter. 3. Define the term trace element and give an example. Atoms and Molecules 4. Draw and label a simplified model of an atom. 5. Distinguish between each of the following pairs of terms: a. neutron and proton b. atomic number and mass number 6. Explain how the atomic number and mass number of an atom can be used to determine the number of neutrons. 7. Explain how two isotopes of an element are similar. Explain how they are different. 8. Describe two biological applications that use radioactive isotopes. 9. Define the terms energy and potential energy. Explain why electrons in the first electron shell have less potential energy than electrons in higher electron shells. 10. Distinguish among nonpolar covalent, polar covalent and ionic bonds. 11. Explain why strong covalent bonds and weak bonds are both essential in living organisms. 12. Distinguish between hydrogen bonds and van der Waals interactions. 13. Give an example that illustrates how a molecule’s shape can determine its biological function. 14. Explain what is meant by a chemical equilibrium. Common Student Misconceptions: 1. The simplified models of the atom (Figure 2.4), electron shells (Figure 2.8), and covalent bonding (Figure 2.11) can confuse students who take them too literally. It is important to make sure that you understand that: Atoms do not have defined surfaces. Electrons do not travel in planetary orbits around the nucleus of the atom. Shared electron pairs are not paired spatially in covalent bonds. Electron shells represent energy levels rather than the position of electrons. 2. Students have difficulty fully grasping the concept of energy, and especially the concept of potential energy. Potential energy can be misunderstood as a substance or fuel that is somehow stored in matter. Understand that potential energy is associated with an object’s ability to move to a lower-energy state, thus releasing some of the potential energy. Return to the concept of potential energy in discussing electron shells, understand that electrons in different electron shells differ in potential energy rather than in position. 3. Students should recognize that weak bonds play important roles in the chemistry of life, despite the transient nature of each individual bond. Page 42 gives the example of the gecko, able to walk on ceilings because of the van der Waals interactions between the ceiling and the hairs on the gecko’s toes. Know that strong and weak bonds are both important in the chemistry of life, and be able to provide examples illustrating this. Stems an- = not (anion: a negatively charged ion) co- = together; -valent = strength (covalent bond: an attraction between atoms that share one or more pairs of outer-shell electrons) electro- = electricity (electronegativity: the tendency for an atom to pull electrons towards itself) iso- = equal (isotope: an element having the same number of protons and electrons but a different number of neutrons) neutr- = neither (neutron: a subatomic particle with a neutral electrical charge) pro- = before (proton: a subatomic particle with a single positive electrical charge) Key Terms for Chapter 2 anion atom atomic mass atomic nucleus atomic number cation chemical bond chemical equilibrium chemical reaction compound covalent bond dalton electron electron shell electronegativity element energy energy level hydrogen bond ion ionic bond ionic compound isotope mass number matter molecular formula molecule neutron nonpolar covalent bond orbital periodic table of the elements polar covalent bond potential energy product proton radioactive isotope reactant salt structural formula trace element valence valence electron valence shell van der Waals interactions Chapter 2 Worksheet 1. Fill out the following chart for the major subatomic particles of an atom. Particle Charge Mass Location Proton Neutron Electron 2. Distinguish between valence # and valence electrons. Also, explain the concept of the octet rule in relation to valence electrons. 3. Diagram each of the following atoms: # of # of # of Valence Atom Protons Neutrons Electrons # Diagram Carbon Hydrogen 4 Oxygen Nitrogen 4. Distinguish between the following bonds: Covalent Ionic Hydrogen polar covalent: nonpolar covalent: 5 Ch. 2 Chemical Context of Life Practice Test 1. About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? a. carbon, sodium, chlorine, nitrogen b. carbon, sulfur, phosphorus, hydrogen c. oxygen, hydrogen, calcium, sodium d. carbon, hydrogen, nitrogen, oxygen e. carbon, oxygen, sulfur, calcium 2. Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates? a. nitrogen b. calcium c. iodine d. sodium e. phosphorus 3. What is the approximate atomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons? a. 15 daltons b. 16 daltons c. 30 daltons d. 31 daltons e. 46 daltons 4. Oxygen has an atomic number of 8 and a mass number of 16. Thus, the atomic mass of an oxygen atom is a. exactly 8 grams. b. exactly 8 daltons. c. approximately 16 grams. d. approximately 16 daltons. e. 24 amu (atomic mass units). 5. Calcium has an atomic number of 20 and an atomic mass of 40. Therefore, a calcium atom must have a. 20 protons. b. 40 electrons. c. 40 neutrons. d. A and B only e. A, B, and C 6. Different atomic forms of an element contain the same number of protons but a different number of neutrons. What are these different atomic forms called? a. ions b. isotopes c. neutronic atoms d. isomers e. radioactive atoms 7. One difference between carbon-12 carbon-14 a. b. c. d. e. and is that carbon-14 has two more protons than carbon-12. two more electrons than carbon-12. two more neutrons than carbon-12. A and C only B and C only 8. Electrons exist only at fixed levels of potential energy. However, if an atom absorbs sufficient energy, a possible result is that a. an electron may move to an electron shell farther out from the nucleus. b. an electron may move to an electron shell closer to the nucleus. c. the atom may become a radioactive isotope. d. the atom would become a positively charged ion, or cation. e. the atom would become a negatively charged ion, or anion. Use the figure below to answer the following questions. 9. Which drawing depicts the electron configuration of oxygen ( 10. O)? Which drawing depicts the electron configuration of nitrogen ( 11. of 6? N)? Which drawing is of an atom with the atomic number 12. Which drawing depicts an atom that is inert or chemically unreactive? 13. a. b. c. d. e. What does the reactivity of an atom depend on? number of valence shells in the atom number of orbitals found in the atom number of electrons in each orbital in the atom presence of unpaired electrons in the outer valence shell of the atom presence of hybridized orbitals in the atom 6 14. What are the chemical properties of atoms whose valence shells are filled with electrons? a. They form ionic bonds in aqueous solutions. b. They form covalent bonds in aqueous solutions. c. They are stable and chemically unreactive or inert. d. They exhibit similar chemical behaviors. e. C and D only Use the information extracted from the periodic table in the figure below to answer the following questions. 15. How many electrons does nitrogen have in its valence shell? a. 2 b. 5 c, 7 d. 8 e. 14 16. Based on electron configuration, which of these elements would exhibit chemical behavior most like that of oxygen? a. carbon b. hydrogen c. nitrogen d. sulfur e. phosphorus Use the figure below to answer the following questions. . 17. a. b. c. d. e. What results from the chemical reaction? a cation with a net charge of +1 a cation with a net charge of -1 an anion with a net charge of +1 an anion with a net charge of -1 A and D 18. What is the difference between covalent bonds and ionic bonds? a. Covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of electrons between atoms. b. Covalent bonds involve the sharing of neutrons between atoms, and ionic bonds involve the sharing of electrons between atoms. c. Covalent bonds involve the sharing of electrons between atoms, and ionic bonds involve the electrical attraction between atoms. d. Covalent bonds involve the sharing of protons between atoms, and ionic bonds involve the sharing of neutrons between atoms. e. Covalent bonds involve the transfer of electrons between atoms, and ionic bonds involve the sharing of neutrons between atoms. 19. Which of the following is not considered to be a weak molecular interaction? a. a covalent bond b. a van der Waals interaction c. an ionic bond in the presence of water d. a hydrogen bond e. A and B only 20. Which of the following describes any reaction that has attained chemical equilibrium? a. The concentration of the reactants equals the concentration of the products. b. The rate of the forward reaction is equal to the rate of the reverse reaction. c. All of the reactants have been converted to the products of the reaction. d. All of the products have been converted to the reactants of the reaction. e. Both the forward and the reverse reactions have stopped with no net effect on the concentration of the reactants and the products. 7 Ch. 3 Water and the Fitness of Life Objectives: The Properties of Water 1. With the use of a diagram or diagrams, explain why water molecules are: a. polar b. capable of hydrogen bonding with four neighboring water molecules 2. List four characteristics of water that are emergent properties resulting from hydrogen bonding. 3. Define cohesion and adhesion. Explain how water’s cohesion and adhesion contribute to the movement of water from the roots to the leaves of a tree. 4. Distinguish between heat and temperature, using examples to clarify your definitions. 5. Explain the following observations by referring to the properties of water: Coastal areas have milder climates than adjacent inland areas. Ocean temperatures fluctuate much less than air temperatures on land. Insects like water striders can walk on the surface of a pond without breaking the surface. If you slightly overfill a water glass, the water will form a convex surface above the top of the glass. If you place a paper towel so that it touches spilled water, the towel will draw in the water. Ice floats on water. Humans sweat and dogs pant to cool themselves on hot days. 6. Distinguish among a solute, a solvent, and a solution. 7. Distinguish between hydrophobic and hydrophilic substances. The Dissociation of Water Molecules 8. Name the products of the dissociation of water and give their concentration in pure water. 9. Define acid, base, and pH. 10. Explain how acids and bases may directly or indirectly alter the hydrogen ion concentration of a solution. 11. Using the bicarbonate buffer system of human blood as an example, explain how buffers work. 12. Briefly explain the causes and effects of acid precipitation. Student Misconceptions 1. To understand the emergent properties of water and the importance of these properties to living things, you must fully understand the structure of water and its ability to form hydrogen bonds with neighboring molecules. 2. Some students think that water forms hydrogen bonds only in the liquid state. Recognize that frozen water molecules form a crystalline lattice, with each water molecule forming four hydrogen bonds; H-bonds form in solid states of matter as well. 3. Recall the difference between physical and chemical changes. An ability to distinguish between these is important in understanding many of the key properties of water, such as its role as a solute and its dissociation to form hydroxide and hydronium ions. 4. Many students do not fully understand the exchange of protons between water molecules. An appreciation of water’s dissociation to form hydroxide and hydronium ions is crucial to understanding acid-base relationships, the effects of excess OH- and H3O+ ions in solution, and the role of buffers. Stems -hydro - water; -philos - loving; -phobos -fearing (hydrophilic: having an affinity for water; hydrophobic: having an aversion to water) -kilo - a thousand (kilocalorie: a thousand calories) 8 Key Terms acid acid precipitation adhesion aqueous solution base buffer calorie (cal) Celsius scale cohesion evaporative cooling heat heat of vaporization hydration shell hydrogen ion hydrophilic hydrophobic hydroxide ion joule (J) kilocalorie (kcal) kinetic energy molarity mole (mol) pH polar molecule solute solution solvent specific heat surface tension temperature 9 Chapter 3 1. Complete the following chart for the properties of water. Property Explanation of Property Example of Benefit to Life Hydrogen bonds hold molecules together and adhere them to hydrophilic surfaces High Specific Heat Temperature changes in environment and organisms are moderated Hydrogen bonds must be broken for water to evaporate Water molecules with high kinetic energy evaporate; remaining molecules are cooler Ice floats Most chemical reactions in life involve solute dissolved in water 10 2. Draw a collection of five (5) water molecules and label the diagram with the following terms: hydrogen, oxygen, polar covalent bond, and hydrogen bond. 3. Complete the following table on pH (the first one is completed as an example). [H+] [OH-] PH Acidic, basic, or neutral? 10-2 10-12 2 acidic 10 –11 3 10-8 8 10-12 10-7 4. Explain how the bicarbonate buffer system works to regulate the pH of human blood. 5. Describe the causes and effects of acid precipitation. 11 Ch 3. Water and the Fitness of Life Practice Test 1. The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called? a. a covalent bond b. a hydrogen bond c. an ionic bond d. a hydrophilic bond e. a hydrophobic bond 2. a. b. c. d. e. Water is able to form hydrogen bonds because oxygen has a valence of 2. the water molecule is shaped like a tetrahedron. the bonds that hold together the atoms in a water molecule are polar covalent bonds. the oxygen atom in a water molecule has a weak positive charge. each of the hydrogen atoms in a water molecule is weakly negative in charge. 7. Desert rabbits are adapted to the warm climate because their large ears aid in the removal of heat due to the a. high surface tension of water. b. high heat of vaporization of water. c. high specific heat of water. d. buffering capacity of water. e. dissociation of water molecules. 8. At what temperature is water at its densest? a. 0°C b. 4°C c. 32°C d. 100°C e. 212°C 9. a. Why does ice float in liquid water? The liquid water molecules have more kinetic energy and thus support the ice. The ionic bonds between the molecules in ice prevent the ice from sinking. Ice always has air bubbles that keep it afloat. Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. The crystalline lattice of ice causes it to be denser than liquid water. 3. What do cohesion, surface tension, and adhesion have in common with reference to water? a. All increase when temperature increases. b. All are produced by ionic bonding. c. All are properties related to hydrogen bonding. d. All have to do with nonpolar covalent bonds. e. C and D only b. 4. Which of the following is possible due to the high surface tension of water? a. Lakes don't freeze solid in winter, despite low temperatures. b. A water strider can walk across the surface of a small pond. c. Organisms resist temperature changes, although they give off heat due to chemical reactions. d. Water can act as a solvent. e. The pH of water remains exactly neutral. The picture below illustrates a solute molecule surrounded by a hydration shell of water. Use it to answer the following question. 5. Water's high specific heat is mainly a consequence of the a. small size of the water molecules. b. high specific heat of oxygen and hydrogen atoms. c. absorption and release of heat when hydrogen bonds break and form. d. fact that water is a poor heat conductor. e. inability of water to dissipate heat into dry air. 6. a. b. c. d. e. Which bonds must be broken for water to vaporize? ionic bonds nonpolar covalent bonds polar covalent bonds hydrogen bonds covalent bonds c. d. e. 10. Based on your knowledge of the polarity of water molecules, the solute molecule is most likely a. positively charged. b. negatively charged. c. without charge. d. hydrophobic. e. nonpolar. 12 11. Which of the following solutions has the greatest concentration of hydrogen ions [H+]? a. gastric juice at pH 2 b. vinegar at pH 3 c. tomato juice at pH 4 d. black coffee at pH 5 e. household bleach at pH 12 12. Which of the following solutions has the greatest concentration of hydroxide ions [OH-]? a. lemon juice at pH 2 b. vinegar at pH 3 c. tomato juice at pH 4 d. urine at pH 6 e. seawater at pH 8 13. Which of the following statements is true about buffer solutions? a. They maintain a constant pH when bases are added to them but not when acids are added to them. b. They maintain a constant pH when acids are added to them but not when bases are added to them. c. They maintain a constant pH of exactly 7 in all living cells and biological fluids. d. They maintain a relatively constant pH. e. They are found only in living systems and biological fluids. 14. One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3) Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion (H+) Thus, H2CO3 HCO3- + H+ If the pH of the blood drops, one would expect a. a decrease in the concentration of H2CO3 and an increase in the concentration of HCO3-. b. the concentration of hydroxide ion (OH-) to increase. c. the concentration of bicarbonate ion (HCO3-) to increase. d. the HCO3- to act as a base and remove excess H+ with the formation of H2CO3. e. the HCO3- to act as an acid and remove excess H+ with the formation of H2CO3. 15. Research indicates that acid precipitation can damage living organisms by a. buffering aquatic systems such as lakes and streams. b. decreasing the H+ concentration of lakes and streams. c. increasing the OH- concentration of lakes and streams. d. washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant growth. e. both B and C 13 Ch 4 Carbon and the Molecular Diversity of Life Objectives The Importance of Carbon 1. Explain how carbon’s electron configuration accounts for its ability to form large, complex, and diverse organic molecules. 2. Describe how carbon skeletons may vary, and explain how this variation contributes to the diversity and complexity of organic molecules. 3. Describe the basic structure of a hydrocarbon and explain why these molecules are hydrophobic. Functional Groups 4. Name the major functional groups found in organic molecules. Describe the basic structure of each functional group and outline the chemical properties of the organic molecules in which they occur. Stems carb- coal (carboxyl group: a functional group present in organic acids, consisting of a carbon atom double-bonded to an oxygen atom and a hydroxyl group) hydro- water (hydrocarbon: an organic molecule consisting only of carbon and hydrogen) iso- equal (isomer: one of several organic compounds with the same molecular formula but different structures and, therefore, different properties) sulf- sulfur (sulfhydryl group: a functional group that consists of a sulfur atom bonded to an atom of hydrogen) thio- sulfur (thiol: organic compounds containing sulfhydryl groups) Key Terms adenosine triphosphate (ATP) amino group carbonyl group carboxyl group functional group hydrocarbon hydroxyl group organic chemistry phosphate group sulfhydryl group Chapter 4 Worksheet 1. Describe the structure of carbon atoms and explain why they are able to function as “backbones” for some many different molecules. 2. Fill in the following table on the functional groups. Functional Group Molecular Formula Names and characteristics of organic & Structural compounds containing the group. Formula -OH Aldehyde or ketone; polar group, water soluble, often found in sugars (carbohydrates) Carboxyl -NH2 Thiols; cross-links stabilize protein structure, often “smelly” compounds Phosphate Ch 4 Carbon and the Molecular Diversity of Life Practice Test 1. a. b. c. d. e. Organic chemistry is a science based on the study of functional groups. vital forces interacting with matter. carbon compounds. water and its interaction with other kinds of molecules. inorganic compounds. 10. Which is an acidic functional group that can dissociate and release H+ into a solution? 11. Which is a basic functional group that can accept H+ and become positively charged? Use the molecules shown in the figure below to answer the following questions. 2. Which property of the carbon atom gives it compatibility with a greater number of different elements than any other type of atom? a. Carbon has 6 to 8 neutrons. b. Carbon has a valence of 4. c. Carbon forms ionic bonds. d. A and C only e. A, B, and C 3. What type(s) of bond(s) does carbon have a tendency to form? a. ionic b. hydrogen c. covalent d. A and B only e. A, B, and C 4. What is the reason why hydrocarbons are not soluble in water? a. The majority of their bonds are polar covalent carbon to hydrogen linkages. b. The majority of their bonds are nonpolar covalent carbon-tohydrogen linkages. c. They are hydrophilic. d. They exhibit considerable molecular complexity and diversity. e. They are lighter than water. 12. Which molecule is water-soluble because it has a hydroxyl functional group? 13. Which molecule is an alcohol? 14. Which molecules contain a carbonyl group? 15. Which molecule has a carbonyl functional group in the form of a ketone? 16. Which molecule has a carbonyl functional group in the form of an aldehyde? 17. Which molecule contains a carboxyl group? Use the figure below to answer the following questions. 18. Which molecule can increase the concentration of hydrogen ions in a solution and is therefore an organic acid? Use the molecules shown in the figure below to answer the following questions.. 5. Which is a hydroxyl functional group? 6. Which is an amino functional group? 7. Which is a carbonyl functional group? 8. Which is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules? 9. 19. Which molecule functions to transfer energy between organic molecules? Which is a carboxyl functional group? 20. Which molecule contains an amino functional group, but is not an amino acid? Ch. 5 The Structure and Function of Macromolecules Objectives The Principles of Polymers 1. List the four major classes of macromolecules. 2. Distinguish between monomers and polymers. 3. Draw diagrams to illustrate condensation and hydrolysis reactions. Carbohydrates Serve as Fuel and Building Material 4. Distinguish among monosaccharides, disaccharides, and polysaccharides. 5. Identify the elements that compose carbohydrates. 6. Identify examples of carbohydrates and describe their functions. 7. Describe the role of symbiosis in cellulose digestion. Lipids Are a Diverse Group of Hydrophobic Molecules 8. Describe the building-block molecules, structure, and biological importance of fats, phospholipids, and steroids. 9. Identify the elements that compose lipids. 10. Distinguish between saturated and unsaturated fats. 11. Identify examples of lipids and describe their functions. Proteins Have Many Structures and Many Functions 12. Distinguish between a protein and a polypeptide. 13. Explain how a peptide bond forms between two amino acids. 14. List and describe the four major components of an amino acid. Explain how amino acids may be grouped according to the physical and chemical properties of the R group. 15. Explain what determines protein conformation and why it is important. 16. Explain how the primary structure of a protein is determined. 17. Name two types of secondary protein structure. Explain the role of hydrogen bonds in maintaining secondary structure. 18. Explain how weak interactions and disulfide bridges contribute to tertiary protein structure. 19. List four conditions under which proteins may be denatured. Nucleic Acids Store and Transmit Hereditary Information 20. List the major components of a nucleotide, and describe how these monomers are linked to form a nucleic acid. 21. Distinguish between: a. pyrimidine and purine b. nucleotide and nucleoside c. ribose and deoxyribose d. 5’ end and 3’ end of a nucleotide 22. Briefly describe the three-dimensional structure of DNA. Student Misconception 1. Students may think that two-dimensional representations of organic molecules are accurate. These molecules are less static than you imagine. Conveniently drawn as linear, monosaccharides usually form rings in aqueous solutions. There may be considerable rotation around single bonds within organic molecules, unless their conformation is stabilized by interactions between regions of the molecule. Understand that 2D drawings of organic molecules are convenient but greatly oversimplified representations of molecular structure. 2. Students may not realize that every protein has primary, secondary, and tertiary structures and may think that any particular protein is characterized only by one level of structure. Each level contributes to protein conformation. 3. The majority of students have difficulty visualizing the different levels of protein structure and the interaction of the regions of the protein molecule. To fully understand levels of protein structure, you must be able to mentally construct three-dimensional images of proteins. This can be very challenging. Try to construct your own 3-D models or look at models online. 4. Students tend to define nucleic acids by the most familiar examples, DNA and RNA, rather than understanding the structure of nucleotide monomers. This causes confusion when students encounter important molecules such as ATP and cAMP and fail to recognize them as nucleotides. Take the time to understand the monomers – building blocks- of nucleic acids Stems con- together (condensation reaction: a reaction in which two molecules become covalently bonded to each other through the loss of a small molecule, usually water) di- two (disaccharide: two monosaccharides joined together) glyco- sweet (glycogen: a polysaccharide sugar used to store energy in animals) hydro- water; -lyse 5 break (hydrolysis: breaking chemical bonds by adding water) macro- large (macromolecule: a large molecule) meros- part (polymer: a chain made from smaller organic molecules) mono- single; -sacchar 5 sugar (monosaccharide: simplest type of sugar) poly- many (polysaccharide: many monosaccharides joined together) tri- three (triacylglycerol: three fatty acids linked to one glycerol molecule) Key Terms alpha (α) helix nucleic acid amino acid nucleotide antiparallel peptide bond beta (β) pleated sheet phospholipid carbohydrate polymer catalyst polynucleotide cellulose polypeptide chaperonin polysaccharide chitin primary structure cholesterol protein condensation reaction purine dehydration reaction pyrimidine denaturation quaternary structure deoxyribonucleic acid (DNA) ribonucleic acid (RNA) deoxyribose ribose disaccharide saturated fatty acid disulfide bridge secondary structure double helix starch enzyme steroid fat tertiary structure fatty acid triacylglycerol gene unsaturated fatty acid glycogen X-ray crystallography glycosidic linkage hydrolysis hydrophobic interaction lipid macromolecule monomer monosaccharide Ch 5 Macromolecules WorksheetFor each of the macromolecules below: list the major functions, list and describe (or draw) the monomers and polymers. Macromolecule Carbohydrates C:H:O 1:2:1 Lipids C, H, O Nucleic Acids C, H, O, N, P Proteins C, H, O, N, S List of Major Functions Monomers or common subunits Structure of subunits Common Polymers or large molecules Structure of Polymers Chapter 4 and 5 Applications: Below are structural formulas for several organic molecules. For each one, circle and label each functional group present and identify the molecule as a carbohydrate, lipid, nucleic acid or protein. EXAMPLE hydroxyl carbonyl amino carboxyl PROTEIN Ch 5 The Structure and Function of Macromolecules Practice Test 1.Which of the following is not one of the four major groups of macromolecules found in living organisms? a. glucose b. carbohydrates c. lipids d. proteins e. nucleic acids 2. Polymers of polysaccharides, fats, and proteins are all synthesized from monomers by which process? a. connecting monosaccharides together (condensation reactions) b. the addition of water to each monomer (hydrolysis) c. the removal of water (dehydration reactions) d. ionic bonding of the monomers e. the formation of disulfide bridges between monomers 3. Which of the following best summarizes the relationship between dehydration reactions and hydrolysis? a. Dehydration reactions assemble polymers, and hydrolysis breaks down polymers. b. Hydrolysis only occurs in the urinary system, and dehydration reactions only occur in the digestive tract. c. Dehydration reactions can occur only after hydrolysis. d. Hydrolysis creates monomers, and dehydration reactions break down polymers. e. A and C are correct. 6. Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. How is lactose classified? a. as a pentose b. as a hexose c. as a monosaccharide d. as a disaccharide e. as a polysaccharide 7. Which of the following is true of both starch and cellulose? a. They are both polymers of glucose. b. They are geometric isomers of each other. c. They can both be digested by humans. d. They are both used for energy storage in plants. e. They are both structural components of the plant cell wall. 8. Humans can digest starch but not cellulose because a. the monomer of starch is glucose, while the monomer of cellulose is galactose. b. humans have enzymes that can hydrolyze the beta c. glycosidic linkages of starch but not the beta d. 4. A molecule with the chemical formula C16H32O16 is probably a a. carbohydrate. b. lipid. c. protein. d. nucleic acid. e. hydrocarbon. 5. If 128 molecules of the general type shown in the figure below were covalently joined together in sequence, the single molecule that would result would be a glycosidic linkages of starch but not the alpha glycosidic linkages of cellulose. humans have enzymes that can hydrolyze the alpha e. glycosidic linkages of cellulose. humans harbor starch-digesting bacteria in the digestive tract. the monomer of starch is glucose, while the monomer of cellulose is maltose. 9. A molecule with the formula C18H36O2 is probably a a. carbohydrate. b. lipid. c. protein. d. nucleic acid. e. hydrocarbon. 10. Triacylglycerol is a a. protein with tertiary structure. b. lipid made with three fatty acids and glycerol. c. lipid that makes up much of the plasma membrane. d. molecule formed from three alcohols by dehydration reactions. e. carbohydrate with three sugars joined together by glycosidic linkages. a. b. c. d. e. polysaccharide. polypeptide. polyunsaturated lipid. monosaccharide. disaccharide. 11. Saturated fatty acids a. are the predominant fatty acid in corn oil. b. have double bonds between carbon atoms of the fatty acids. c. have a higher ratio of hydrogen to carbon than do unsaturated fatty acids. d. are usually liquid at room temperature. e. are usually produced by plants. 12. The molecule shown in the figure below is a a. b. c. d. e. polysaccharide. polypeptide. saturated fatty acid. triacylglycerol. unsaturated fatty acid. 13. The hydrogenation of vegetable oil would result in which of the following? a. a decrease in the number of carbon-carbon double bonds in the oil (fat. molecules b. an increase in the number of hydrogen atoms in the oil (fat. molecule c. the oil (fat. being a solid at room temperature d. A and C only e. A, B, and C 14. What is the structure shown in the figure below? 16. The chemical reaction illustrated in the figure below results in the formation of a (an) a. b. c. d. e. ionic bond. peptide bond. glycosidic linkage. ester linkage. phosphodiester linkage. 17. Which bonds are created during the formation of the primary structure of a protein? a. peptide bonds b. hydrogen bonds c. disulfide bonds d. phosphodiester bonds e. A, B, and C 18. Which type of interaction stabilizes the alpha and the beta a. b. c. d. e. a. b. c. d. e. starch molecule protein molecule steroid molecule cellulose molecule phospholipid molecule 15. The 20 different amino acids found in polypeptides exhibit different chemical and physical properties because of different a. carboxyl groups attached to an alpha carbon b. amino groups attached to an alpha carbon c. side chains (R groups). d. alpha carbons. e. asymmetric carbons. helix pleated sheet structures of proteins? hydrophobic interactions nonpolar covalent bonds ionic bonds hydrogen bonds peptide bonds 19. A strong covalent bond between amino acids that functions in maintaining a polypeptide's specific three-dimensional shape is a (an) a. ionic bond. b. hydrophobic interaction. c. van der Waals interaction. d. disulfide bond. e. hydrogen bond. 20. At which level of protein structure are interactions between the side chains (R groups. most important? a. primary b. secondary c. tertiary d. quaternary e. all of the above 21. What would be an unexpected consequence of changing one amino acid in a protein consisting of 325 amino acids? a. The primary structure of the protein would be changed. b. The tertiary structure of the protein might be changed. c. The biological activity or function of the protein might be altered. d. Only A and C are correct. e. A, B, and C are correct. 22. All of the following molecules are proteins except a. hemoglobin. b. transthyretin. c. collagen. d. lysozyme. e. glycogen. 23. What is the term used for a change in a protein's threedimensional shape or conformation due to disruption of hydrogen bonds, disulfide bridges, or ionic bonds? a. hydrolysis b. stabilization c. destabilization d. renaturation e. denaturation 24. What is the term used for a protein molecule that assists in the proper folding of other proteins? a. tertiary protein b. chaperonin c. enzyme protein d. renaturing protein e. denaturing protein 25. Of the following functions, the major purpose of RNA is to a. transmit genetic information to offspring. b. function in the synthesis of protein. c. make a copy of itself, thus ensuring genetic continuity. d. act as a pattern or blueprint to form DNA. e. form the genes of higher organisms. 26. Which of the following descriptions best fits the class of molecules known as nucleotides? a. a nitrogenous base and a phosphate group b. a nitrogenous base and a pentose sugar c. a nitrogenous base, a phosphate group, and a pentose sugar d. a phosphate group and an adenine or uracil e. a pentose sugar and a purine or pyrimidine 27. Which of the following are nitrogenous bases of the pyrimidine type? a. guanine and adenine b. cytosine and uracil c. thymine and guanine d. ribose and deoxyribose e. adenine and thymine 28. Which of the following statements best summarizes the structural differences between DNA and RNA? a. RNA is a protein, whereas DNA is a nucleic acid. b. DNA is a protein, whereas RNA is a nucleic acid. c. DNA nucleotides contain a different sugar than RNA nucleotides. d. RNA is a double helix, but DNA is single-stranded. e. A and D are correct. 29. If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence a. 5'TAACGT3'. b. 3'TAACGT5'. c. 5'UAACGU3'. d. 3'UAACGU5'. e. 5'UGCAAU3'. 30. The element nitrogen is present in all of the following except a. proteins. b. nucleic acids. c. amino acids. d. DNA. e. monosaccharides. The following questions are based on the 15 molecules illustrated below. Each molecule may be used once, more than once, or not at all. 31.Which of the following combinations could be linked together to form a nucleotide? a. 1, 2, and 11 b. 3, 7, and 8 c. 5, 9, and 10 d. 11, 12, and 13 e. 12, 14, and 15 32. Which of the following molecules contain(s) an aldehyde type of carbonyl functional group? a. 1 b. 4 c. 8 d. 10 e. 1 and 4 33. Which of the following molecules act as building blocks (monomers) of polypeptides? a. 1, 4, and 6 b. 2, 7, and 8 c. 7, 8, and 13 d. 11, 12, and 13 e. 12, 13, and 15 34. A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between a. one molecule of 9 and three molecules of 10. b. three molecules of 9 and one molecule of 10. c. one molecule of 5 and three molecules of 9. d. three molecules of 5 and one molecule of 9. e. one molecule of 5 and three molecules of 10. 35. Which of the following molecules has (have) a functional group that frequently is involved in maintaining the tertiary structure of a protein? a. 2 b. 3 c. 9 d. 11 e. 9 and 11 AP Biology Math & Statistics Graphing and Data Skills Practice 1. In designing an experiment or other scientific study, why do scientists need to sample from a population rather than an entire population? 2. Suppose you are designing an experiment to test the effects of nicotine on the heart rate of rats. What are the disadvantages of having too small a sample size (i.e., testing too few rats)? What are the disadvantages of having too large a sample size? 3. Explain the difference between discrete variables and continuous variables. Give an example of each. 4. Explain the differences between quantitative and qualitative data. Give an example of each. 5. What is a null hypothesis? 6. What are some steps that scientists can take in designing an experiment to avoid false negatives? AP Biology Graphing Practice Introduction Graphing is an important procedure used by scientists to display the data that is collected during a controlled experiment. Line graphs must be constructed correctly to accurately portray the data collected. Many times the wrong construction of a graph detracts from the acceptance of an individual’s hypothesis. A graph contains five major parts: A. The title B. The independent variable C. The dependent variable D. The scale for each variable E. The legend A. The TITLE depicts what the graph is about. By reading the title, the reader should get an idea about the graph. It should be a concise statement placed above the graph. B. The INDEPENDENT VARIABLE is the variable that can be controlled by the experimenter. It usually includes time (dates, minutes, hours), depth (feet, meters), temperature (Celsius). This variable is placed on the x axis (horizontal line). The DEPENDENT VARIABLE variable is the variable that is directle affected by the independent variable. It is the result of what happens resulting from influence by the independent variable. Example: How many oxygen bubbles are produced by a plant located five meters below the surface of the water? The oxygen bubbles are dependent on the depth of the water. This variable is placed on the y axis (vertical line). The SCALE for each variable: In constructing a graph, one needs to know where to plot the points representing the data. In order to do this, a scale must be employed to include all the data points. In order to conserve the amount of space on a graph, the scale should start with 0 and increase based on intervals such as: multiples of 2, 5, 10, 20, 25, 50, or 100. The scale will be dictated by the values of your data. The LEGEND is a short, descriptive narrative concerning the graph’s data. It should be short, concise and placed under the graph. The MEAN for a group of variables: To determine the mean for a group of data, divide the sum of values by the total number of values to get an average. The MEDIAN for a group of variables: To determine the median or “middle” for an even number of values, put the values in ascending order and take the average of the two middle values. For example, 2, 3, 4, 5, 9, 10 Add 4+5 (2 middle values) and divide by 2 to get 4.5. The MODE for a group of variables: The mode for a group of values is the number that occurs most frequently. For example, 2, 5, 8, 2, 6, 11 The number 2 is the mode because it occurred most often (twice.) Problem A: Using the following data, create a graph and answer the questions. Depth (meters) 2 5 10 16 25 30 Plant A # of bubbles/minute 29 36 45 32 20 10 Plant B # of bubbles/minute 21 27 40 50 34 20 1. What is the independent variable? Why? 2. What is the dependent variable? Why? 3. What title would you give the graph? 4. Complete the table: Mean Depth Bubble Plant A Bubble Plant B Median Mode Title:______________________________________________________________________________________ Problem B Diabetes is a disease affecting the insulin-producing glands of the pancreas. If there is not enough insulin being produced by these cells, the amount of glucose in the blood will remain high. A blood glucose level above 140 for an extended period of time is not considered normal. This disease, if not brought under control, can lead to severe complications and even death. Answer the following questions concerning the data below and then graph it. Time After Eating (hours) 0.5 1 1.5 2 2.5 3 4 Glucose ml/Liter of Blood Subject A 170 155 140 135 140 135 130 Glucose ml/L of Blood Subject B 180 195 230 245 235 225 200 1. What is the dependent variable and why? 2. What is the independent variable and why? 3. What title would you give the graph? 4. Which, if any, of the above subjects (A or B) has diabetes? 5. What data do you have to support your hypothesis? 6. If the time period were extended 6 hours, what would be the expected blood glucose level for Subject B? Title:__________________________________________________________________________________________ Problem C Temperatures were obtained in November in fairly arid area of Nevada. At two different sites, temperature readings were taken at a number of heights above and below the soil surface. One site was shaded by a juniper whereas the other was not. Table 1 Condition Air Air Air Air Soil Surface Humus Mineral Mineral Height (cm) from Soil Surface 150 90 60 30 0 -6 -15 -30 Construct a line graph and plot the data Temperature (C) Beneath Forest Cover 18 18 18 18 16 12 9 7 Temperature (C) Unshaded Field 20 21 20 21 33 19 15 12 Problem E A species of insect has been accidently introduced from Asia into the US. The success of this organism depends on its ability to find a suitable habitat. The larval stage is very sensitive to changes in temperature, humidity, and light intensity. Expose to situations outside the tolerance limits results in a high mortality rate. Study the data below. Table 3 Temperature (C) Mortality (%) 15 16 17 18 19 20 21 22 23 24 25 100 80 30 10 0 0 0 0 20 80 100 Relative Humidity (%) 100 90 80 70 60 50 40 30 20 10 0 Mortality (%) 80 10 0 0 0 50 70 90 100 100 100 Light Intensity (fc) 300 400 600 800 1000 1200 1400 1600 1800 2000 Mortality (%) On the graphs, plot line graphs for the effects of temperature, humidity, and light intensity and mortality rates. 0 0 10 15 20 20 90 95 100 100