1 AP Biology Summer Assignment: 2012-2013 As you may have heard, the College Board is revising the AP Biology curriculum and exam for the 2012-13 school year. There will be a greater emphasis placed on skills and scientific reasoning. You will be required to apply the biological concepts you are learning to design experiments and explain problems. For this reason, your summer assignment will focus on two things – reviewing very basic concepts and practicing experimental design. During the school year, this college-level introductory biology class will still move quickly as you learn more complex ideas and carry out lab experiments and procedures. You will be expected to do a lot of reading and studying on your own in order to come to class prepared to discuss and tackle the harder problems and ideas. For Part 1 of your summer assignment, you will need the Campbell Biology, 9th edition textbook and you should also obtain an AP Biology Test study guide such as 5 Steps to a 5 or something equivalent. What follows is a reading guide that covers several topics that you should have mostly learned in your first year of biology and during chemistry. As you read Chapters 2-6 of the textbook, you should answer the reading guide questions (although, if you want, you may incorporate the answers to the questions in a note taking format as you read each chapter). You should complete all of these questions before you arrive back at school. Your questions will be checked for completion and you will be given a test on this reading within the first week. It will be expected that you are comfortable with these concepts because little, if any, time will be spent discussing these topics at a basic level in class and it will be assumed that you understand them. For Part 2 of your assignment, you will be practicing designing your own experimental question and procedure. There are warm-up questions to refresh your memory on what to include in a good controlled experiment. This is an exercise in designing an experiment; you do NOT actually have to do the experiment. The goal is to have you think in a more complex way that goes beyond the experiments you did for your regular biology science project. Think of an experimental question from your own experience or something you’ve wondered about. After deciding on a question, you will identify the variables in your experiment, write a testable “If/then” hypothesis and write a procedure that could be used to test your experimental question. You should come up with your own procedure that tests your question, not just copy something that you find online, but if you do use other sources for ideas, cite them. Part 2 will be collected on the first day of class to evaluate your ability to design a testable experiment. You may discuss this assignment with each other; however, ALL written work must be done individually. No two assignments or experimental questions and procedures should be identical to someone else’s. If you have questions over the summer, Mr. Roes can be reached by email at sroes@masterschool.org 1 2 PART 1: READING CHAPTERS 2-6 Chapter 2: Chemical Context of Life Essential question: How do chemical interactions between atoms make life possible? Concept 2.1: Matter consists of chemical elements in pure form and in combinations called compounds 1. Define and give an example of the following terms: matter, element, compound 2. What four elements make up 96% of all living matter? 3. What is the difference between an essential element and a trace element? 4. Explain how table salt has emergent properties. Concept 2.2: An element’s properties depend on the structure of its atoms 5. Sketch a model of an atom of helium, showing the electrons, protons, neutrons and atomic nucleus. 6. Here are some more terms that you should firmly grasp. Define each term: atomic number, atomic mass, isotope, energy, electron shells 7. Which is the only subatomic particle that is directly involved in the chemical reactions between atoms? 8. What is the atomic mass of carbon? ________ Atomic number? ________ 9. How many electrons does carbon have? ________ neutrons? ________ 10. What is potential energy? 11. Here is an electron distribution diagram for sodium: a. How many valence electrons does it have? b. How many protons does it have? Concept 2.3: The formation and function of molecules depend on chemical bonding between atoms 12. Define molecule. 13. What is meant by electronegativity? 14. Explain the difference between a nonpolar covalent bond and a polar covalent bond. 15. Make an electron diagram of water. Which element is most electronegative? Why is water considered a polar molecule? Label the regions that are more positive or more negative. 16. Another type of bond is the ionic bond. Define this type of bond and give an example of an ionic compound. 2 3 17. What is a hydrogen bond? 18. Here is a list of the types of bonds and interactions discussed in this section. Place them in order from the strongest to the weakest: hydrogen bonds, van der Waals interactions, covalent bonds, ionic bonds. 19. What is meant by chemical equilibrium? Does this imply equal concentrations of each reactant and product? Chapter 3: Water and the Fitness of the Environment Essential question: Why do we need water to live? Concept 3.1: The polarity of water molecules results in hydrogen bonding 20. Explain again why water is considered polar. 21. Draw 3 water molecules using structural formulas. Add + and – signs to indicate the charged regions of each molecule. Then, indicate the hydrogen bonds. 22. How many hydrogen bonds can a single water molecule form? Concept 3.2: Four emergent properties of water contribute to Earth’s suitability for life 23. Distinguish between cohesion and adhesion. 24. Why is a water strider able to walk on water? 25. What does it mean for water to have a high specific heat? How does water’s specific heat compare to alcohol’s? 26. Explain how hydrogen bonding contributes to water’s high specific heat. 27. Summarize how water’s high specific heat contributes to the moderation of temperature. How is this property important to life? 28. What is heat of vaporization? Explain at least three effects of this property on living organisms. 29. Ice floats! So what? Consider what would happen if ponds and other bodies of water accumulated ice at the bottom. Describe why this property of water is important. 30. Now explain why ice floats. Why is 4°C the critical temperature in this story? 31. Review and define these terms: solvent, solution, solute. 32. Explain why water is such a great solvent. 33. Define hydrophobic and hydrophilic. Concept 3.3: Acidic and basic conditions affect living organisms 34. What two ions form when water dissociates? 35. Water, which is neutral with a pH of 7, has an equal number of H+ and OH- ions. Now, define acid and base. 36. Because the pH scale is logarithmic, each numerical change represents a 10X change in ion concentration. a. How many times more acidic is a pH of 3 compared to a pH of 5? b. Explain the difference between a pH of 8 and a pH of 12 in terms of H+ concentration. 37. Even a slight change in pH can be harmful! How do buffers moderate pH change? 38. Discuss how CO2 emissions affect marine life and ecosystems. 3 4 Chapter 4: Carbon and the Molecular Diversity of Life Essential Question: Why does carbon play a central role in all living organisms? Concept 4.1: Organic chemistry is the study of carbon compounds 39. What was the conclusion from the results of Stanley Miller’s experiment? Concept 4.2: Carbon atoms can form diverse molecules by bonding to four other atoms 40. Make an electron diagram of carbon. a. How many valence electrons does carbon have? b. How many bonds can carbon form? c. What type of bonds does it form with other elements? 41. What is a hydrocarbon? Name two examples. Are hydrocarbons hydrophobic or hydrophilic? 42. Define isomer. (don’t mix this word up with isotope) 43. Identify the three types of isomers. For each type, give a key character and an example. Concept 4.3: A small number of chemical groups are key to the functioning of biological molecules 44. Here is an idea that will recur throughout your study of the function of molecules: Change the structure, change the function. You see this in enantiomers, you will see it in proteins and enzymes, and now we are going to look at testosterone and estradiol. Notice how similar these two molecules are, and yet you know what a vastly different effect each has. Label each molecule in the sketch to the bottom and circle the differences. 45. Define functional group. How do they affect molecular function? Circle and identify three functional groups in the molecule below 4 5 46. What chemical change occurs to ATP when it reacts with water and releases energy? How is this molecule important to life? Chapter 5: The Structure and Function of Large Biological Molecules Essential question: What are the main types of molecules that form the basis of all living organisms? Concept 5.1: Macromolecules are polymers, built from monomers 47. The large molecules of all living things fall into just four main classes. Name them. 48. What is a polymer? A monomer? 49. Monomers are connected in what type of reaction? What occurs in this reaction? 50. Large molecules (polymers) are converted to monomers in what type of reaction? 51. Consider the following reaction: C6H12O6 + C6H12O6 C12H22O11 a. The equation is not balanced; it is missing a molecule of water. Write it on the correct side of the equation b. What kind of reaction is this? c. Is C6H12O6 (glucose) a monomer, or a polymer? d. To summarize, when two monomers are joined, a molecule of _____________ is always removed. Concept 5.2: Carbohydrates serve as fuel and building material 52. Let’s look at carbohydrates, which include sugars and starches. First, what are the monomers of all carbohydrates? 53. Have you noticed that all sugars end in –ose. This root word means _____________. 54. There are two categories of polysaccharides. Name them and give examples. 55. Why can you not digest cellulose? What organisms can? Concept 5.3: Lipids are a diverse group of hydrophobic molecules 56. Lipids include fats, waxes, oils, phospholipids and steroids. What characteristics do all lipids share? 57. What are the building blocks of fats? 5 6 58. If a fat is composed of 3 fatty acids and 1 glycerol molecule, how many water molecules will be removed to form it? Again, what is this process called? 59. What is the difference between saturated and unsaturated fats? 60. List four important functions of fats? 61. Here is a figure that shows the structure of a phospholipid. Label the sketch to show the phosphate group, the glycerol and the fatty acid chains. Also indicate the region that is hydrophobic and the region that is hydrophilic. 62. Which of the two fatty acid chains in the figure with question 61 is unsaturated? Label it. How do you know it is unsaturated? 63. Sketch the phospholipid bilayer structure of a plasma membrane. Label the hydrophilic heads, hydrophobic tails, and location of water. Why are all the tails located in the interior? Concept 5.4 Proteins include a diversity of structures, resulting in a wide range of functions 64. What is the monomer of proteins? What are different functions of proteins? 65. There are four levels of protein structure. Refer to Figure 5.20 and summarize each level. a. Primary (1°) b. Secondary (2°) – (alpha helix and beta pleated sheet) c. Tertiary (3°) d. Quaternary (4°) 66. Do you remember when, in Chapter 4, we said, “Change the structure, change the function”? Explain how that principle applies to sickle cell disease. Why is the structure changed? 6 7 67. Besides mutation, which changes the primary structure of a protein, protein structure can be changed by denaturation. Define denaturation, and give at least three ways a protein may become denatured. Concept 5.5: Nucleic acids store, transmit and help express hereditary information 68. The components of a nucleic acid are a sugar, a nitrogenous base and a phosphate group. Draw and label a nucleotide. 69. Notice that there are five nitrogen bases. Which four are found in DNA? Which four are found in RNA? 70. How do ribose and deoxyribose sugars differ? 71. Why are the strands of DNA said to be antiparallel? Chapter 6: A Tour of the Cell Essential question: How do cell structures contribute to its functions? (You do not need to know the types of microscopy in Concept 6.1) Concept 6.2: Eukaryotic cells have internal membranes that compartmentalize their functions 72. Which two domains consist of prokaryotic cells? 73. A major difference between prokaryotic and eukaryotic cells is the location of their DNA. Describe this difference. 74. Sketch a prokaryotic cell, label each of these features and give its function or description: cell wall, plasma membrane, bacterial chromosome, nucleoid, cytoplasm, flagella 75. Why are cells so small? Describe the relationship of surface area to volume. Concept 6.3: The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosomes 76. What is the structure and function of the nuclear envelope? 77. Found within the nucleus are the chromosomes, made of chromatin. What are the two components of chromatin? 78. What is the structure and function of the nucleolus? 79. What is the relationship between the nucleus and the ribosomes? 80. Ribosomes in any type of organism are all the same, but we distinguish between two types of ribosomes based on where they are found and the destination of the protein product made. What is the difference between bound and free ribosomes? Concept 6.4: The endomembrane system regulates protein traffic and performs metabolic functions in the cell 81. Make a chart of all the structures and functions of the components of the endomembrane system (there should be six things). 7 8 82. What is the difference in structure and function of the rough ER and the smooth ER? (don’t worry about the cis vs. trans Golgi stuff, but you should know the function of the Golgi itself) 83. One function of the lysosomes is intracellular digestion of particles engulfed by phagocytosis. Describe this process of digestion. What human cells carry out this process? 84. Explain the role of lysosomes in Tay-Sachs disease. 85. Use this figure below to explain how the elements of the endomembrane system function together to secrete a protein. Label as you explain Concept 6.5: Mitochondria and chloroplasts change energy from one form to another. 86. What is the endosymbiont theory? Summarize three lines of evidence that support the model of endosymbiosis of chloroplasts and mitochondria. 87. What is the structure and function of mitochondria and chloroplasts? 88. Explain the important role played by peroxisomes. 8 9 Concept 6.6: The cytoskeleton is a network of fibers that organizes structures and activities in the cell 89. What is the structure and function of the cytoskeleton? 90. There are three main types of fibers that make up the cytoskeleton. Name them. 91. Animal cells have a centrosome that contains a pair of centrioles. Plant cells do not have centrioles. What is another name for centrosomes? What is believed to be the role of centrioles? (You don’t need to know more details about the structure and function of the different types of fibers.) Concept 6.7: Extracellular components and connections between cells help coordinate cellular activities 92. What are three functions of the cell wall? 93. How do plant cells communicate with one another? 94. How do animal cells communicate with one another? PART 2: DESIGNING AN EXPERIMENT Warm-up: Refresh your memory on the components of good experimental design Carefully read the paragraph below. Answer the following questions. During gym class Alison noticed that her friend Tiffany always ran faster than her. Alison knew that they exercised equally, so she wondered what could cause Tiffany to run so fast. Alison began to compare herself and Tiffany to see what could cause the difference in speeds. She noticed that Tiffany was taller and wondered if height affected speed. Alison predicted that taller people were able to run faster, but wanted to check her prediction. She asked her gym teacher if she could test her idea because the class was all girls and she thought this would help her get accurate results. Alison measured all of her classmates’ height in centimeters and recorded it in her chart. Each classmate then ran one mile while Alison timed them with a stopwatch and recorded the data in seconds. She then began to review her data and look for the answer to her question. 1. What question is Alison trying to answer? 2. What made her want to answer this question? 3. What is Alison’s hypothesis? (Write her hypothesis as an “If….then” statement with a specific outcome.) 4. What is being measured or observed in this experiment (dependent variable)? 9 10 5. What factor does Alison think might cause the dependent variable measurement to change (independent variable)? 6. What parts of the experiment were kept the same throughout (constants or controlled variables)? 7. Is there a control group in this experiment (something she compared back to)? Design your own experiment – Type the components of your experiment design by addressing the following 1. Make some observations in your everyday life. What is a question or problem that you wonder about and would like to test in an experiment? 2. What is the dependent variable? 3. What factors could affect the dependent variable? From this list, highlight the one independent variable that you will be testing? How will you manage the effects of the other variables? 4. Ideally, your experiment should have a control group and an experimental group (or groups). However, some good scientific questions examine the relationship between two things (like the example for the warmup questions) and do not have a control group. Identify the control group and experimental group in your experiment. If you do not have a control group, explain why not. 5. Identify at least five constant or controlled variables. These are parts of the experiment that remain the same to prevent affecting the experiment’s outcome 6. How will you collect measurements as data? How often? What units are you using? 7. Write your hypothesis using an “If…then” statement. Be sure your hypothesis predicts a specific outcome. 8. Write a clear procedure that other people can follow step by step. Be sure to include how you will collect data or observations, how often, and what units of measurement to use. 10 11 9. List any sources you used in researching your question or procedure using MLA format. 11