Professor:bowes, Herrera, Julian, Herrerabaerbolker, oppenheimer, AL-BUBAIE, Staff, BARBAZUK, DAVIDJULIAN, JAMIEGILLOOLY, REBEKKADARNER, IDK, Allen, ALL, Diego, kaplan, Grower, bear, Bhotika,SmritiS, Gillooly,JamesF;Levy,HazelC;Barbazuk,WilliamBradley, JOHN, Hart, Yoo, Al-Dubaie,Abdulrahman, Baer,Charles, Oppenheimer,DavidG, Yoo,Mi-Jeong, Douglas,NormanA., McDaniel,Stuart, Norman,Douglas, herrera,joan, GILOOLY, Opinhimer, Chen,Sixue, Miyamoto,MichaelMasao, N/A, Multiple Professors, Todd Palmer, han,kin-lan, DR., john gordon, Keith Choe, Burleigh,JohnGordon, Ellen davis BSC 2010 EXAM The exam consists of 30 multiple choice questions (answer sheet numbers 1- 30) worth 2 pts each. You are to choose the most correct answer and bubble the corresponding letter in the answer sheet. The question will be marked wrong if you have more that one choice bubbled. If you erase an answer, make sure that you remove all marks. BEST OF LUCK ON THIS EXAM! 1. Fluorine has an atomic number of 9. How many electrons does it have in its outer electron shell? (A) 6, (B) 9, (C)8, (D) 7 or (E) 5. 2. Which of the following is (are) true about the following two atoms below? Atom 1 Atom 2 6 protons 6 protons 6 neutrons 6 neutrons 6 electrons 5 electrons (A) atom 2 is a cation (B) they have the same atomic mass numbers (C) both have two electrons in the inner shell (D) all of the above (E) none of the above 3. The bonds that stabilize water molecules in ice are relatively weak and break when heat is added. Which kind of bond is this (refers to the bond BETWEEN WATER MOLECULES)? (A) ionic, (B) hydrogen, (C) polar covalent, (D) non-polar covalent or (E) hydrophobic interaction. 4. Table sugar (sucrose) has a g formula weight of around 342 g. If you wanted to make one liter of a 1 mM (milliMolar) solution of sucrose you would have to weigh out how much sucrose? (A) 0.342 g, (B) 1 mg, (C) 34.2 g, (D) 3.42 mg or (E) 100 g. 5. Which statement is true about enantiomers (aka stereoisomers)? (A) they always have identical properties in biological systems, (B) they have an asymmetric carbon and are mirror images of each other, (C) they have variations in arrangement about a double carbon bond, (D) they have a different number of carbons or (E) differ in covalent relationships of atoms. 6. A nitrogen atom (atomic number = 7) has the potential to form ____ covalent bonds. (A) two, (B) none, it only forms ionic bonds, (C) four, (D) none, it only forms hydrogen bonds or (E) three. 2 7. The functional group shown to the side is a(n) (A) amino group (B) carboxyl group (C) hydroxyl group (D) aldehyde (E) ketone. 8. A10 mM (millimolar) solution is _________________ concentrated than a 1 ?molar (micromolar) solution. (A) 100 times more, (B) 100 times less, (C) 1,000 times less, (D) 10,000 times more or (E) 1,000 times more. 9. Water’s tendency to cool slowly on at night reflects its property of- (A) cohesion and adhesion, (B) dissolving water soluble molecules, (C) high latent heat of vaporization, (D) high specific heat or (E) low heat capacity. 10. Water molecules will tend to coat the surface of most proteins because the surface has amino acid residues that are- (A) charged, (B) hydrophobic, (C) non polar, (D) unable to form hydrogen bonds, (E) all of the above. 11. The p sub-orbitals in the second electron shell can hold a maximum of ________ electrons (refers to the maximum total number of p electrons in this shell). (A) 1, (B) 8, (C) 3, (D) 4 or (E) 6. 12. Carbon is not very electronegative which means that – (A) it ALWAYS forms polar covalent bonds, (B) it cannot donate electrons to other atoms, (C) it is not particularly reactive, (D) all of the above or (E) none of the above. 13. When a substance is added to water and its pH goes from pH 4.5 to pH 10 we know that – (A) a weak acid has been added , (B) the acid content has decreased, (C) the OH- concentration has decreased, (D) all of the above or (E) none of the above. 14. The concentration of protons [H+ ] in a solution with a pH of 5 is- (A) 5 M, (B) 0.005 M, (C) –0.00005 M, (D) 0.0002 M or (E) 0.00001 M. 15. A particular atom has an atomic number of 10 and consists of the following: 10 protons, 10 electrons and 11 neutrons. This atom is- (A) not charged, (B) a positively charged ion, (C) a negatively charged ion, (D) an amphipathic ion or (E) all of the above. 16. Ice floats because________ (A) its volume decreases going from the liquid to crystal state, (B) its density increases going from the liquid to crystal state, (C) its specific heat decreases going from the liquid to crystal state, (D) its density decreases going from the liquid to crystal state, or (E) none of the above. 17. If an atom has two electrons only in the third shell, what would be the atomic number of this atom (assume this is a neutral atom)? (A) 11, (B) 10, (C) 9, (D) 8 or (E) 12. 3 18. Condensation reactions - (A) release water, (B) always involve carbon-carbon bond formation, (C) consume water, (D) do not involve water or (E) take place when polymers are broken down. 19. The compound depicted below is a(n) _________. (A) phospholipid, (B) amino acid, (C) monoglyceride, (D) monosaccharide, or (E) none of the above. 20. A triglyceride containing highly saturated fatty acids will (A) likely be solid at room temperature, (B) be negatively charged, (C) will have no carbon-carbon bonds, (D) will have two fatty acids only or (E) none of the above. 21. A phospholipid is amphipathic because (A) it is highly polar, (B) it contains a positively charged region only, (C) it is nonpolar, (D) it has both polar and non-polar regions or (E) it completely lacks charge. 22. The interior of a micelle consists of (A) phosphate, (B) choline, (C) water, (D) polar substances or (E) non-polar hydrocarbon “tails”. 23. The sugar depicted below is a(n) _________ . (A) aldose, (B) monosaccharide, (C) hexose (hint: hex = 6), (D) all of the above or (E) none of the above. 24. The secondary structure of a protein is stabilized primarily by ________ . (A) hydrophobic interactions, (B) polar covalent bonds, (C) dissulfide bonds, -S-S-, (D) non-polar covalent bonds or (E) hydrogen bonds. 4 5 25. The peptide bond is formed between (A) two sulfur atoms, (B) two nitrogen atoms on adjacent amino acids, (C) the hydrogen bonding of one amino acid and to another amino acid, (D) the carboxyl group of one amino acid and the amino group of another amino acid or (E) none of the above. 26. Suppose an element has an atomic number of 10. The valence of this element would be ____. (A) +2, (B) –1, (C) 0, (D) –2 or (E) +2. 27. Technetium (Tc) has an atomic number of 43 and an atomic mass number of 99. How many neutrons does Tc have in its nucleus? (A) 99, (B) same as the number of electrons, (C) 43, (D) 142 or (E) 56. 28. At pH 7 ______________. (A) the solution is said to be neutral, (B) the concentration of H+ ([H+ ])equals the concentration of OH- ([OH- ]), (C) the product of [H+ ] times [OH- ] is equal to 10-14M2 , (D) all of the above or (E) none of the above. 29. The major role of carbohydrates in animals is (A) energy storage, (B) insulation, (C) cushion, (D) all of the above or (E) none of the above. 30. Which functional group is not found in monosaccharides ? (A) hydroxyl, (B) ketone, (C) aldehyde, (D) all of the above or (E) none of the above.