Chem 60 Takehome Test 2 Student Section

Transcription

1 Multiple choice: 1 point each. Mark only one answer for each question. 1. are composed primarily of carbon and hydrogen, but may also include oxygen, nitrogen, sulfur, phosphorus, and a few other elements. A. alkenes B. phospholipids C. inorganic compounds D. organic compounds 2. are proteins, carbohydrates, lipids, and DNA, and belong to a class of organic compounds. A. biomolecules B. inorganic compounds C. phospholipids D. polysaccharides 3. are compounds that do not contain carbon and hydrogen. A. diastereomers B. inorganic compounds C. biomolecules D. organic compounds 4. show all atoms, but show bonds only when necessary. Lone pairs of electrons are not shown. A. skeletal structures B. condensed structural formulas C. structural isomers D. fluid mosaic model 5. Organic compounds with the same molecular formula but different connectivity of atoms are known as. A. diastereomers B. structural isomers C. enantiomers D. cis-trans isomers 6. reactions produce a water molecule while bonding two molecules together. A. hydrogenation B. hydrolysis C. condensation D. oxidation 7. reactions consume a molecule of water while a molecule is broken into two smaller molecules. A. hydrogenation B. hydrolysis C. condensation D. oxidation 8. consists of amylose, a linear chain of glucose, and amylopectin, a branched chain of glucose. A. starch B. chlolesterol C. glycogen D. chitin 9. The explains why similar molecules with similar polarity will dissolve each other. A. law of constant composition B. rule of solubility C. law of conservation of mass D. rule of multiple proportions 10. The configuration forms kinks in the hydrocarbon chains of oils, preventing chains from stacking together as closely as those in a fat. A. trans B. cis 11. are the major lipids in cell membranes. A. fatty acids B. cholesterol C. phospholipids D. polysaccharides 12. The describes the structure of the cell membrane. A. lipid bilayer model B. fluid mosaic model 13. Which of the following fatty acids is an essential fatty acid? Oleic acid Arachidonic acid Linoleic acid Stearic acid 14. What functional groups are present in the following structure? CH3 C C CH2OH Alcohol and an alkene A ketone and an alkyne An aldehyde and a ketone An alcohol and an alkyne Page 1 of 6

2 15. When two compounds are made up of the same number and kind of atoms, but differ in their molecular structure they are known as: isotopes homologs isomers hydrocarbons 16. Which of the following compounds is the enantiomer of: 17. How many chiral carbon atoms are in this structure? Page 2 of 6

3 18. Which of the following functional groups is just a carbon double bonded to an oxygen atom? Alcohol Thiol Carbonyl Ester 19. A carbohydrate with 6 carbons and an aldehyde functional group is called a(n): ketohexose aldohexose ketopentose aldopentose 20. The most abundant monosaccharide in nature is: mannose galactose glucose fructose 21. Which of the following is an aldehyde functional group? 22. The configuration at which carbon atom determines if a monosaccharide is D or L? The lowest numbered chiral carbon The highest chiral carbon The chiral carbon closest to the aldehyde or keto group The carbon of the primary alcohol group 23. In the Benedict's test: an aldehyde is oxidized a brick red precipitate is formed the copper (II) ion is reduced all of these are true 24. When an organic molecule gains hydrogens it is said to be: reduced oxidized both oxidized and reduced neither oxidized or reduced 25. α-d-glucose and β-d-glucose are: enantiomers anomers disaccharides a racemic mixture Page 3 of 6

4 26. Which of the following compounds is the enantiomer of the following? 27. Lactose is made from D-glucose and: mannose glucose galactose ribose 28. Which of the following is the storage form of glucose in the liver and muscle tissue? Amylose Amylopectin Glycogen Cellulose 29. Which of the following is the structural polysaccharide in plants? Amylose Amylopectin Glycogen Cellulose 30. The polysaccharide the makes up the exoskeleton of insects is: cellulose glycogen chitin amylose 31. Which of the following blood types is considered to be the universal blood donor? Type B Type A Type AB Type O Page 4 of 6

5 32. Which of the following is a pyranose ring? Both of these are pyranose rings. Neither of these is a pyranose ring. 33. For a series of small molecules of comparable molecular weight, which one of the following choices lists the intermolecular forces in the correct increasing order? London forces < dipole dipole forces < hydrogen bonds hydrogen bonds < dipole dipole forces < London forces dipole dipole forces < hydrogen bonds < London forces London forces < hydrogen bonds < dipole dipole forces 34. Soaps can be described as: esters of fatty acids salts of fatty acids long chain acids all of these 35. The long hydrocarbon tails of soap molecules are: hydrophilic and attracted to water hydrophobic and attracted to water hydrophobic and attracted to oils hydrophilic and attracted to oils 36. Fats are generally at room temperature and are obtained from. solids; animals liquids; plants solids; plants liquids; animal 37. In a lipid bilayer: the hydrophilic heads of the molecules point towards each other all the molecules are triglycerides the hydrophobic heads point to the hydrophilic tails the hydrophobic tails of the molecules point toward each other Page 5 of 6

6 38. Which of the following alkanes has the highest boiling point? CH3CH2CH2CH2CH2CH3 Short Answers: Each problem below is worth 4 points. Write your complete answer legibly or risk losing points. 39. Why is lettuce considered roughage and not an energy source for our bodies? What make its components so different from other carbohydrate sources that we cannot get energy from it? 40. What is the difference between the terms hydrophobic and hydrophilic? 41. What is meant by the term "partially hydrogenated vegetable oil"? Page 6 of 6