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Unformatted text preview: Version 026 – Exam 1 – sathasivan – (48985) 1 This print-out should have 51 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 10.0 points Why are water molecules able to form hydro- gen bonds? 1. Oxygen has a weak negative charge and the hydrogen has a weak positive charge. cor- rect 2. An oxygen atom in a water molecule has a strong positive charge. 3. Hydrogen atoms in a water molecule have weak negative charges. 4. Oxygen has 6 valence electrons. 5. A water molecule is shaped like a tetra- hedron. Explanation: The hydrogen in one water molecule and the oxygen in the adjoining water molecule will make H-bonds. 002 10.0 points Consider the following. C OH H H C OH H C OH H C H HO C OH H C H O C OH H H C OH H C OH H C H HO C O C OH H H glucose fructose What is the difference between these two molecules? 1. the composition of the elements C, H and O 2. the number of carbon, hydrogen, and oxygen atoms 3. the types of carbon, hydrogen, and oxygen atoms 4. the number of covalent bonds 5. the arrangement of carbon, hydrogen, and oxygen atoms correct Explanation: Two representations for C 6 H 12 O 6 003 10.0 points Animals combine 1000 of the monomer H HO CH 2 OH H H OH OH H H OH O and store them as 1. glycogen. correct 2. steroid. 3. DNA. 4. starch. 5. protein. Explanation: First you need to identify the monomer as a simple sugar and then figure out that a polymer of 1000 such monomers will make a polysaccharide. Then recall the storage polysaccharide in animal glycogen. Only plants make starch as storage polysaccharide. 004 10.0 points You have eaten a potato chip that contained starch made of 10,000 glucose monomers com- Version 026 – Exam 1 – sathasivan – (48985) 2 bined together. After complete digestion through hydroly- sis, this will yield I) 10,000 glucose molecules. II) 10,000 water molecules. III) 9,999 water molecules. IV) 9,999 glucose molecules. 1. I and III only 2. III and IV only 3. II only 4. I and II only 5. I only correct Explanation: Hydrolysis is the breakdown of a larger molecule to simpler molecule. It uses wa- ter and does not form any water molecules. Hence a complete digestion of a polymer with 10,000 monomers will yield only 10,000 monomers. To go into further details, it will utilize 9999 water molecules to break down this larger polymer. 005 10.0 points The molecule C H H H C H H C H C H C H H C H C H C O OH is a 1. saturated fatty acid. 2. polyunsaturated fatty acid. correct 3. protein. 4. polysaccharide. 5. monounsaturated fatty acid. Explanation: The two double bonds on the hydrocarbon and the carboxyl group indicate that this is polyunsaturated fatty acid....
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This note was uploaded on 03/21/2011 for the course BIO 311C taught by Professor Satasivian during the Spring '08 term at University of Texas.
- Spring '08