T LOGARITHMS HAT MIGHT BE USEFUL log 2 log 3 log 4 log 5 log 6 log 7 log 8 log 9 log 10 = 0.30 = 0.48 = 0.60 = 0.70 = 0.78 = 0.84 = 0.90 = 0.95 = 1.0 anti log 1 anti log 2 anti log 3 anti log -1 anti log -2 anti log -3 = 10 = 100 = 1000 = 1/10 = 1/100 = 1/ 1000
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Please choose the best answer for each question. 1.Which of the following is FALSE, regarding prokaryotes? a. Prokaryote genomic DNA is comprised of one double-stranded circular molecule. b. Prokaryote DNA is contained in a region called the nucleoid. c. Archaebacteria and Eubacteria are prokaryotes. d. The bacterium, E. coli, and the yeast, S. cerevisiae are prokaryotes. 2.The four major groups of macromolecules are: a. DNA, RNA, proteins and lipids b. Acids, bases, proteins and carbohydrates c. Proteins, water, lipids and carbohydrates d. Proteins, nucleic acids, carbohydrates and lipids 3. All chiral amino acids have (L) stereochemical designation T F 4. The following mRNA AAAUAUGCUCGGGGAGUGG, when translated, will yield the peptide : ______________________ 5. Which of the following is TRUE? a. DNA is used as a template by the ribosome during translation. b. RNA is transcribed by the ribosome during the synthesis of protein. c. DNA is used as a template during transcription of RNA. d. DNA is used as a template during translation of RNA. 6.Which of the following, regarding lipids, is FALSE? a. Lipids are largely non-polar in nature. b. Cell membranes are made up of lipid polymers. c. Lipids provide structure. d. Lipids act as signaling molecules. 7.Which of the following is FALSE? a. Proteins are polymers of amino acids joined together by ionic bonds b. In aqueous solution, proteins are surrounded by a hydration shell of water molecules c. In aqueous solution, proteins form hydrogen bonds with water molecules. d. In aqueous solution, polar amino acids are most commonly on the outside of a protein, and interact with the solution. 8.Which of the following are TRUE regarding covalent bonds: a. Bonding valence electrons are attracted by both nuclei in the bond b. Bond length depends on the nature of the atoms bonded and the number of electrons participating in the bond. c. Electrons are shared between the bonding pair of atoms. d. All the above are true e. Only a. and c. are true 9.TRUE or FALSE A molecule that has several resonance structures has more structural stability than a molecule that does not. T F 2
For 11-14, rank the relative strength of the following intermolecular forces from lowest (1), to highest (5) strength, by placing a number, from 1 to 4, in the space provided. 10.__ Double Covalent Bonds 11.__ Single Covalent Bonds 12.__ Hydrogen Bonds in water 13.__ London dispersion forces 14.__ Hydrogen Bonds in hexanes 15.Select the correct statement in describing the genetic code: a. Each of the 64 codons encodes one amino acid. b. One codon can correspond to more than one amino acid. c. One amino acid can be encoded by two or more codons. d. All of the above are true. 16.Which of the following is NOT one of non-covalent forces involved in intermolecular interactions? a. Hydrophobic interactions b. Ionic interactions c. Hydrogen bonds d. Disulfide bonds e. London dispersion effect 17.Select the CORRECT answer regarding peptides. a. To stabilize quaternary structures, individual polypeptide subunits covalently bond their free amino and carboxyl ends b. Peptide bonds show partial double bond characteristics c. Interactions between amino acid side chains determine whether any two given amino acids residues will form a peptide bond d. There are no correct answers here. 18.Based on the pKa values of side chains at pH 7, which of these tripeptides contains, from N'- to C'- terminus, acidic-neutral-basic residues? a. Glu-Pro-Arg b. Val-Met-His c. Lys-His-Asn d. Asn-Ala-Gly
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19.Choose the INCORRECT statement regarding alpha helices a. are held in position by hydrogen bonds between main chain atoms b. are ordered with side chains (R-groups) projecting outward from the helix c. Hydrogen bonds that maintain the structure of the helix form in a direction parallel to the axis of the helix d. Prolines are amino acids commonly found throughout the length of alpha helices. 20.Select the incorrect statement regarding weak forces a. Hydrogen bond formation is important for maintaining DNA structure. b. Ionic interactions are attractive or repulsive forces between charged atoms. c. The dielectric strength of the solution has little effect on strength of ionic interactions. d. Strength of ionic interactions depends on the proximity of the ions. e. Ionic interactions are stronger between charged molecules in non-polar solvents. 21.Choose the incorrect answer: a. Each water molecule can form up to four hydrogen bonds. b. Mammalian intercellular pH is maintained primarily by the dihydrogen phosphate/hydrogen phosphate buffering system c. Mammalian blood pH of is commonly maintained by the carbonate/bicarbonate system. d. Buffers maintain pH best within 1 unit of their pKa values. e. There is no incorrect answer, all of the above are true. 22.Choose the correct statement. a. The 20 common amino acids found in proteins are in the D configuration. b. The following amino acids have basic side chains: arginine, lysine, and histidine. c. The following amino acids have aromatic side chains: tyrosine, methionine, and phenylalanine. d. Proline does not participate in peptide bond formation, as it does not have a free amino group. For a given peptide with the sequence, (+)M(-)EGA(+)R(-), select true or false for questions 23 through 26. 23.The net charge on this peptide at physiological PH is 0 TF 24.The net charge on this peptide at pH 11 is -1 TF 25.This peptide contains 5 peptide bonds TF 26.This peptide can form disulfide bonds TF
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True or False, for questions 27 through 31: The following amino acids have side chains that are hydrophobic : 27.Lysine TF 28.Tryptophan TF 29.Aspartic acid TF 30.Phenylalanine TF 31.Serine TF 32.True or false: The pKa of an acid varies with temperature. T F 33.Find the correct statement. a. Aromatic amino acids absorb light at a wavelength of 280 nm. b. Methionine dimerizes via its sulfur-containing side chain (cysteine) c. Phenylalanine is often modified by phosphorylation. (Tyrosine) d. D-methionine is the first amino acid incorporated during protein synthesis. (Lmethionine) 34.Which of the following is the major driving force in protein folding? a. electrostatic interactions between adjacent side chains b. the hydrophobic effect c. ionic interactions between beta-sheets d. hydrogen bonding between alpha-helices 35.Alpha helices are maintained by a. hydrogen bonds between R-groups of adjacent amino acids b. hydrogen bonds between R-groups 3-4 residues apart c. ionic bonds between side chains 3-4 residues apart d. hydrogen bonds between main chain atoms 3-4 residues apart Please state the pH of the following: 36.0.1M HCL pH=__________________ 37.0.1M NaOH pH=_______________
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Given the peptide shown below in yellow, please answer the following questions: 38.How many amino acids make up this peptide?________ 39.At pH 7, the net charge on this peptide is __________ 40.At pH 2, the net charge on this peptide is _________ 41.At pH 13, the net charge on this peptide is _________ 42.The first four amino acids from left to right are: a. Phenylalanine, Glycine Glycine, Tyrosine b. Tyrosine, Glycine, Glycine, Phenylalanine c. Tryptophan, Alanine, Alanine, Tyrosine d. Tyrosine, Glycine, Glycine, Tryptophan 43.The R-group of amino acid 4 can be a participate in which of the following interactions : a. Hydrogen bonding b. Van der waals forces c. Ionic bonds d. Disulfide bonds
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44.For an acid, at pH6, the molar concentration of the protonated species is 0.1, and deprotonated species is 0.2. What is the pKa of this acid________ 45.What is the pOH- of the solution in question 44? ___________ 46.A patient comes into the emergency room. She is breathing heavily with shallow, rapid respirations. Her blood work comes back and the blood pH is 7.0 this patient shows signs of: a. acidosis, her blood pH is higher than normal b. alkalosis, her blood pH is lower than normal c. acidosis, her blood pH is lower than normal d. alkalosis, her blood pH is higher than normal 47.Determine the G of a system in kJ/mole =_____________________ H = 1 kJ T=298K S system = 10 Joules 48.Circle all that apply: An closed system: a. does not exchange heat with its surroundings b. does not exchange matter with its surroundings c. does exchange heat with its surroundings 49. Please circle all of the pyrimidine bases shown below: Uracil Cytosine Thymine 50.Which is the correct statement. a. Nucleosides are compounds containing a pentose sugar covalently joined through a glycosidic bond to a nitrogenous base. b. Nucleotides are compounds containing a pentose sugar covalently joined through a glycosidic bond to a nitrogenous base. c. Nucleosides differ from nucleotides because the nitrogenous base in nucleosides lacks a 2-OH. In nucleotides, the nitrogenous base contains a 2-OH. d. The pentose sugars of deoxyribonucleotides in duplex DNA are in the pyranose form. 51.What is the difference between GDP and dGDP? a. dGDP has an extra amino group attached to carbon 6 in the purine ring. b. dGDP has an extra phosphate attached to the 2' carbon of the ribose. c. dGDP is reduced at the 2' carbon of the ribose. d. dGDP is reduced at carbon 6 of the purine ring
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52.Chargaffs rule states which of the following regarding the composition of DNA: a. the molar concentration of purines = the molar concentration of pyrimidines b. the molar concentration of cytosine = the molar concentration of adenine c. the molar concentration of cytosine = the molar concentration of guanine d. a,b,c e. a, c 53.10% of the nucleotides in a cell's DNA contain adenine. What is the guanine content of this cell's DNA? According to Chagraffs rule: A = T and C = G a. 20% A% + T % + C% + G% = 100% b. 30% 10% +10% + C% + G% = 100% c. 40% C% + G% = 100% - 20% d. 60% C% + G% = 80 and C% = G%, so 80/2 = G% e. 70% 54.Circle the correct one of each pair The backbone of DNA is (Hydrophilic) while the bases are. (Hydrophobic) 55.If the pKa of an acid is 3, HAA- +H+ and the pH of the solution is 5, what is the proportion of [A-]/[HA] in solution? (you may leave the answer in ratio format and in a power of 10) 56.For the problem above, which species is present in higher concentration, A- or HA?
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