Biol200 Wi12 PracticeExam2

Biol200 Wi12 PracticeExam2 - TO STUDENTS: In the interest...

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Unformatted text preview: TO STUDENTS: In the interest of time, this practice exam was created prior to finalizing the slides prior to the 2nd exam. Hence these questions may cover information not discussed in class and thus not on the exam. Page 1 of 6 1 If a cell is placed out of its normal environment and into the environment indicated below, how will water move through the cellular membrane? (Put an X in the correct box for each environment) Environment Hypotonic Hypertonic Isotonic 2 Water moves out of the cell No net transfer of water in or out of cell Water moves into the cell Indicate how the following properties typically affect the permeability and fluidity of phospholipid bilayers. Write either: "increases", "decreases" or "does not change". One of the eight entries has been done for you. Property Permeability Fluidity Increases More saturated hydrocarbon tail Shorter fatty acid chain length Higher temperature 3 The plasma membrane performs many critical functions in the cell. In the table below, indicate two different types of macromolecules that are components of the plasma membrane in a eukaryotic cell. Also, describe one important structural feature and one function of each membrane component you listed. On example answer is shown. Macromolecule Structural feature Function Phospholipids Amphipathic Selectively permeable 4 Name two categories of immune cells that CD4 (helper T) cells influence? (~2-5 words) __________________________ __________________________ Page 2 of 6 5 The front page of this test has drawings of a plant and an animal cell, along with some named component structures. You can use this information to help you answer the questions in the problems below. Problem: Space aliens have attacked and disassembled the cells of all organisms on earth, (except you). You have the daunting task of redesigning new eukaryotic cells. Having learned about the components of cells, you are confident you can do a good job. a. What 3 components are necessary for the cells to live? Give a short justification for each. The first one has been done for you: Component Plasma membrane b. What single additional component should you add to the cells so it can thrive in the following conditions: i. A sunny environment that does not offer an alternate source of chemical energy __________________________ ii. A very dry environment __________________________ To assist with intracellular communication (especially in a very large cell) _________________________ 6 Use your acquired knowledge about cellular respiration and fermentation to answer the following: A long distance runner will burn more carbohydrates in a race run at: (Circle one) a high mountain top sea level Justify your answer. (~1-2 sentences) Justification To enclose the contents and maintain the integrity of the cell Page 3 of 6 7 Match the cell structure in the left column to one of its functional activities in the right column. Identify one and only one match per structure. One match has already been made for you. E Lysosome Structure A B C D E F G Tight junction Mitochondria Rough ER Cytoskeleton Golgi apparatus Plasma membrane Associated Function or Activity Protein processing Protein synthesis Signal processing Watertight seal Waste processing Intra-cell communication DNA replication 8 In photosynthesis, glucose and O2 are produced from carbon dioxide and water (reaction shown below). In this process, carbon atoms are reduced and oxygen atoms are oxidized (electrons are not shown). The resulting glucose molecule can then be used as a source of potential energy for biochemical reactions. Rank the bonds indicated as A, B and C according to the highest to lowest potential energy. A" O" C" O" B" H" +""Energy" O" O" C" +" H" O" +" 6"CO2" +" 6"H2O" 6"O2" +" 1"C6H12O6" Highest Potential Energy Middle Potential Energy Lowest Potential Energy __________ __________ __________ 9 Energetic coupling refers to the transfer of free energy produced from ATP hydrolysis to drive a different chemical reaction. Provide one reason why life be impossible without energetic coupling? (~1-3 sentences) Page 4 of 6 10 Indicate 4 immune cell types that respond when a human is exposed to a pathogen. For each cell type, indicate whether an initial exposure can lead to a quicker response following a second exposure to the same pathogen. CD4+ T cell is shown as an example. Cell type Quicker response nd upon 2 exposure (Y/N) + CD4 T cell Yes 11 You have been hired by a drug company as a biologist. The company has developed drugs to treat several cellular disorders. However, the chemical properties of the drugs do not allow them to bind to the relevant target well enough or enter the relevant cells. The company chemist asks you to suggest modifications to the drugs so that they will bind the target better or enter the cells that need the treatment. Using the toolbox of possible molecular modifications listed on the right side of the table below, indicate the modifications you would suggest to deliver the drug to the targets listed in the left column. Identify one and only one modification per target. One modification has already been made for you. Drug target Modification to make D Helper T cell Cell membrane Cell surface Antigen presenting cells HIV particles A B C D E Add methyl groups Add CD4 molecule Add antibody to MHC proteins Add polar groups Add CD4 receptor ligand 12 Which ONE of the following cell types is critical to directly carrying out tasks in both the innate and adaptive immune responses? (Circle one cell type) Natural Killer cells Macrophages Platelets Red blood cells Plasma cells B-cells T-cells Mast cells Describe one function of the cell type you have chosen? (~1 sentence) Page 5 of 6 13 Virus infection of a cell can be lytic or lysogenic. a. What is the difference between a lytic and a lysogenic viral infection? (~1-2 sentences) b. Which type of infection is more likely to give rise to a life-long infection? (Circle one) lytic infection Lysogenic infection c. Why do you think so? (~1-2 sentences) 14 Do retroviruses violate the Central Dogma of Molecular Biology? Explain why or why not. (~1-2 sentences) 15 Refer to figure of a virus life cycle below. What processes do the arrows labeled A, B, and C depict? (feel free to explain in your own words) a. Arrow A (~1 sentence) b. Arrow B (~1 sentence) c. Arrow C (~1 sentence) Page 6 of 6 ...
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This note was uploaded on 03/08/2012 for the course BIOL 200 taught by Professor Jimlara/stevehauska/hannalerhoula-baker during the Spring '09 term at University of Washington.

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