Takehome group assignment #1 - Individual worksheet NAME

Transcription

1 Takehome group assignment #1 - Individual worksheet NAME Answer the questions below, on your own (pp. 1-5). Then get together with your group, discuss your answers and complete the final group worksheet (pp. 6-8) to submit for grading. Include the names of all group members on the group sheet with the participation score for each member listed after their name. Part I: chemical bonds problems

2 Part II: Functional Groups Crossword puzzle: fill in the name of the circled functional group in the crossword below

3 Part III- chemistry of water 1) Explain the difference between ionic and covalent bond formation by describing the following molecules: a) the salt MgCl2 and b) the covalent molecule methane, CH4. 2) Draw the Lewis dot structure for a water molecule. Using a chemical explanation, explain why water is a polar molecule. (use the term electronegativity in your answer). 3) Draw 3 water molecules. Indicate the covalent bonds within each molecule and some of the hydrogen bonds that could form between these molecules. Explain why hydrogen bonds are weak but are also very important in biology. Describe what kind of molecules can form hydrogen bonds. 4) Explain why salt, and polar substances like sugar, dissolve in water but fats do not. 5) List 3 examples of interesting behavior of water that you can observe in the world around you. For each, identify the emergent property of water that makes it possible, and using a chemical explanation, explain why water exhibits that behavior (ie, indicate how hydrogen bonding explains the observation). (for example, you could explain why adding salt to snowy roads prevents ice formation. )

4 Part IV- cellular organelles and the endomembrane system. 1. Label the following diagram of a eukaryotic cell with the cellular structures listed in q Briefly describe the function of the following subcellular structures: Ribosomes: Mitochondria: Nuclear envelope: Nuclear pores: Nucleosome: Rough endoplasmic reticulum: Smooth endoplasmic reticulum: Golgi bodies: Plasma membrane: Lysosomes: Centrioles: List 3 structures that are not found in the animal cell above, but would be present in a plant cell. 3) How do the rough ER and smooth ER differ?

5 4) What are lysosomes? What types of molecules would be found inside a lysosome? Why might a lysosome fuse with or link up with a food vacuole? 5) In what organelle does cellular respiration take place? 6) In what organelle are molecules moved from the ER to the Golgi bodies? What broader system is this a part of? 7) Describe the pathway of the endomembrane system for delivering cell proteins to their proper destination. Briefly outline the path a protein would take if its final destination is to be excreted from the cell (vs to be used in the cytosol). 8) Briefly describe the exterior surface of the cell. How do ECM proteins (extracellular membrane proteins) get outside the cell (ie, what process is used to deliver them to the cell membrane)? What is the primary function of membrane glycoproteins? 9) What is a centriole? In what type of cell (plant or animal) is it found? What does it do for the cell? 10) Name the 3 main types of cytoskeletal proteins and briefly state their main function: 1) 2) 3) 11) Describe the function of each of the cell-cell junctions below, in one sentence. Also state if the junction occurs in plant or animal cells, or in both. Plasmodesmata: Tight junctions: Gap junctions: Desmosomes:

6 Group work to turn in for grading Group member names Participation score ( 1, 0.75, 0.5, or 0) INSTRUCTIONS: Complete this worksheet as a group. Turn in just one copy for the group, including each member s name and participation score (ranging from 0, 0.5, 0.75 or 1 for full participation) as determined by the group. (Groups should have 3-5 people. It is ok to form groups with students from different sections) Part I- chemistry of water review 1) a-draw 3 water molecules indicating both the covalent and hydrogen bonding occurring within and between them. b- Using a chemical explanation, explain why water forms hydrogen bonds. 2) Explain how water s polarity accounts for its unique emergent properties. Include at least one example. 3) Draw a molecule with the chemical formula C 3H 8. Draw another similar molecule, but with an alcohol group attached to the second carbon. Will these two molecules behave the same in water? Explain your answer. 4) List the 4 macromolecules of life. Identify a) the small molecules they are made up of, b) the type of bond holding them together, and c) their primary function in cells. macromolecule Subunit molecule Type of bond in polymer Cellular function Amino acids Carbohydrates Information storage Ester bond (but Not a polymer)

7 5) Draw a polar amino acid and a nonpolar amino acid. Show how a condensation reaction between them will form a peptide bond (making a protein dimer). Part II- Cellular organelles and the endomembrane system review 5) List 2 ways the nucleus is involved in protein synthesis. 6) What do ribosomes do? Are they found freely floating in the cytoplasm OR are they found attached to another organelle OR both? Explain your answer. 7) You are studying a drug that is known to block vesicle formation in the Golgi. You put some of it on some cells for a few hours and then determine the localization of all the newly synthesized Na/K ATPase (a transport protein that is normally present in cell membranes and exchanges sodium and potassium ions across the plasma membrane). Where would you expect to see this newly synthesized protein accumulate in the treated cells (would it be in the nucleus, cytoplasm, ER, golgi, or cell membrane)? Explain why.

8 8) Cell City Analogy In a far away city called Grant City, the main export and production product is the steel widget. Everyone in the town has something to do with steel widget making and the entire town is designed to build and export widgets. The town hall has the instructions for widget making, widgets come in all shapes and sizes and any citizen of Grant can get the instructions and take them to a shop to begin making their own widgets. Widgets are produced in small shops around the city, these small shops can be built by the carpenter's union (whose headquarters are in town hall). As each widget is constructed, they are sometimes placed on special carts which can deliver the widget anywhere in the city. In order for a widget to be exported from the city the carts take the widget to the postal office, where the widgets are packaged and labeled for export. Sometimes widgets don't turn out right, and the "rejects" are sent to the scrap yard where they are broken down for parts or destroyed altogether. The town powers the widget shops and carts from a hydraulic dam that is in the city. The entire city is enclosed by a large wooden fence, only the postal trucks are allowed outside the city. Match the parts of the city (underlined) with the parts of the cell. a. Mitochondria b. Ribosomes c. Nucleus d. Endoplasmic Reticulum e. Golgi Apparatus f. Protein g. Cell Membrane h. Lysosomes i. Nucleolus j. vesicles Part III- Misconceptions For each question, identify a misconception that your group discovered while working on this assignment. State the original misconception and include a corrected explanation in your answer. 1) List a misconception that your group had about the formation of chemical bonds and/or the chemistry of water. 2) List a misconception that your group had about cellular structure (functions of organelles, protein synthesis and delivery by cells, extracellular matrix proteins, cell-cell junctions, etc). 3) List one more misconception on any topic from chapter 1-4.