AP Biology homework Chapter 2

Routine homework requirements:

·         (Routine homework is 10% of the quarter grade. Other graded assignments, including tests and quizzes, will be 90%.) Assignments turned in  late will be penalized. If you cannot answer a question using the textbook, try to research it on my webpage  http://pages.cthome.net/apbio/. If you still are stuck, bring it to my attention in class. Do NOT let it slide, everything is important in AP Bio.

·         Answer each question on lined paper, no frizzies, please. Do not rewrite the question, but staple the question sheet behind your answers. This will save time and allow you to refer to it when you review for a test.

·         Turn in to my "In" box for your class on the teacher’s desk in M 211.

·         Write your name, the date you turn it in, and don’t forget honor system statement and your class section number (AP Bio 2 or 4) at the top.

Read Chapter 2 in Campbell

·         1. Which six elements make up almost all of living matter?

·         2. Give the chemical symbols, atomic number, and atomic mass of each of these elements.

·         3. Which elements account for most of the remaining percentage? (These total less than 2%)

·         4. What does the atomic number tell you about the atomic structure of any element?

·         5. Briefly describe each subatomic particle, its approximate weight (in a.m.u.)and charge.

·         6. Explain the term isotope.

·         7. A carbon atom has 6 protons and the most common isotope has 6 neutrons. A rare isotope has 7 neutrons. What is the atomic mass of the rare isotope?

·         8. What are energy levels? Orbitals?

·         9. How many electrons may exist in the second shell? In a 2s orbital?

·         10. What is the relationship between electron energy and its distance from the nucleus?

·         11. What are covalent bonds?

·         12. Explain the nature of a covalent bond. Identify two types and explain how they differ.

·         13. What determines a molecule's shape? How may the shape be changed?

·         14. What is the significance of a molecule’s shape to biological systems?

·         15. Differentiate between polar and nonpolar covalent bonds. Give a specific example of each type.

·         16. Describe the nature of ionic bonds.

·         17. Describe the nature of hydrogen bonds.

·         18. The atomic number of sulfur is 16 and the atomic number of hydrogen is 1. If these elements are combined, they are likely to form a covalently bonded compound, hydrogen sulfide. Its molecular formula would be ______. Explain how to find the answer to this question only from these data.

Chapter 3 Homework

·         Read chapter 3 in Campbell

 

·         1. Describe the water molecule. Include a diagram, the type of bonding it uses, and the relationship one water molecule has to its neighbors (in liquid state).

·         2. Name some types of molecules that are hydrophobic. Name some hydrophilic molecules.  How can you identify a given molecule as either type?

·          3. Define and compare “cohesion” with “adhesion”.  

·          4. Explain how surface tension occurs in water.

·          5. How does water's surface tension compare to most other molecules?

·          6. What is the value of:  the specific heat of water? of vaporization of water?

·          7. If a gram of water at sea level is heated from 37 degrees to 101 degrees, how much heat would be absorbed by the water? 

·         8. Why does ice float? What significance does this have for organisms?

·         9. What is a hydration shell?

·         10. What is the relationship between disassociation and acid-base ?  (class notes or internet)

·         11. Exactly define the number of hydrogen and hydroxide ions at pH 6.

·         12. What are these values at pH 8?

·         13. What are buffers and how do they function?

·         14. Define molarity. Describe how you would make a 1 molar solution of sucrose.