Practice Exam I- 2010

Practice Exam I- 2010 - 1. A carbon atom bound to another...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1. A carbon atom bound to another carbon atom may transiently attract a hydrogen atom that is bound to a carbon atom. The best explanation for this fact is: a) Carbon to carbon bonds are, in actuality, slightly polar. b) Electrons may accumulate by chance in one part of a molecule creating a region of charge. c) Carbon to hydrogen bonds are, in actuality, slightly polar. d) Electrons usually spend significantly more time around one of the two atoms participating in a covalent bond, even if this bond is non‐polar covalent. e) Atoms participating in covalent bonds are not always stable. 2. Oxygen is a strongly electronegative element. This fact means all of the following except: a) An oxygen atom tends to exert a stronger pull on the electrons it shares with a less electronegative atom than the other atom does. b) Oxygen atoms tend to form polar covalent bonds with less electronegative atoms. c) An oxygen atom may carry a partial negative charge when bound to less electronegative atoms. d) In the periodic table, oxygen is found in the second to last column on the right side (next to the column containing the noble gases). e) There is no incorrect answer choice above. 3. Which of the following statements about ions is false? a) Once an atom ionizes, the number of its protons no longer equals the number of its electrons. b) An anion has more electrons orbiting its nucleus than it has protons in its nucleus. c) Regardless of its charge, an ion can easily interact with water molecules in an aqueous solution. d) Ions are less stable than neutral atoms with unfilled outermost energy levels. e) A cation can attract an anion even if they did not exchange an electron with one another in the process of becoming ions. 4. The compound NaCl comes apart in water because: a) Hydrogen bonds are stronger in water than ionic bonds. b) Covalent bonds are stronger in water than ionic bonds. c) Ionic bonds are stronger in water than hydrogen bonds. d) The oxygen atoms of the water molecules surround the chloride ions. e) The hydrogen atoms of the water molecules surround the chloride ions. 5. A particular fat is solid at room temperature. Which of the following statements is most likely true? a) The hydrocarbon chains of the fatty acids of the triglyceride are polyunsaturated. b) The hydrocarbon chains of the fatty acids of the triglyceride contain many cis double bonds. c) The hydrocarbon chains of the fatty acids of the triglyceride are fully saturated with hydrogen atoms. d) The hydrocarbon chains of the fatty acids of the triglyceride contain no trans double bonds. e) The hydrocarbon chairs of the fatty acid of the triglyceride are mostly polar and allow for extensive van der Waals interactions. 6. Which of the following statements about water molecules is false? a) The cohesion of water molecules to one another creates a surface tension at an air‐ water interface. b) There are fewer hydrogen bonds between an individual water molecule and its neighbors in ice than in the liquid phase. c) The numerous hydrogen bonds between water molecules in the liquid phase account for the high heat of vaporization of water. d) The numerous hydrogen bonds between water molecules in the liquid phase account for the high specific heat of water. e) There are no false statements above 7. A change in the quaternary structure of a protein would most likely: a) Lead to a change in the primary structure of the protein. b) Lead to a change in the function of this protein, but only if this protein was composed of one polypeptide. c) Lead to a change in the van der Waals interactions of the secondary structure. d) Not have an effect on the function of this protein. e) None of the above 8. Two hydrophobic amino acids (such as isoleucine and valine) would be found on the ______ if that protein _______. Fill in the blanks with answer choices that correctly complete the sentence. a) Outside of a globular protein; was found in the cytoplasm. b) Inside of a globular protein; was embedded in the fatty acid portion of the lipid bilayer. c) Inside of a globular protein; was found in the cytoplasm. d) Outside of a globular protein; was found in an aqueous solution. e) Inside of a globular protein; was found in a non‐polar solution. 9. Which of the following statements about a strand of RNA is true? a) The number of purines equals the number of pyrimidines in the strand. b) Three of the RNA nucleotides contain double‐ringed nitrogenous bases. c) The sugar of an RNA nucleotide is less polar than the sugar of a DNA nucleotide. d) There is no 5’→ 3’ directionality in an RNA strand. e) There are no true statements above. 10. A phospholipid in a lipid bilayer can differ from a second phospholipid in that same bilayer in all of the following ways except: a) The number of carbons in its fatty acid tails. b) The number of carbon‐to‐carbon double bonds in its fatty acid tails. c) The number of fatty acid tails it contains. d) The position of double bonds within its fatty acids tails. e) The identity of the “head” group attached to the phosphate group. Answers: 1. b 2. d 3. d 4. e 5. c 6. b 7. e 8. c 9. e 10. c ...
View Full Document

This note was uploaded on 10/27/2010 for the course BIO 102 taught by Professor Alaie during the Fall '08 term at CUNY Hunter.

Ask a homework question - tutors are online