BMB 401 Exam 1 Practice Questions well answered to pass, Exams of Nursing

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BMB 401 Exam 1 Practice Questions

Select the true statement: A. Nucleic acid's are comprised of nucleotides linked together by phosphodiester bonds. B. Series of charged amino acids in conservative order are common and stabilize alpha helices. C. In proteins, coils in loops are not considered secondary structural elements. D. The central region of alpha helices is a hollow tube. E. None of the above are true. - correct answer ✔✔A Peptide bonds have partial double bond characteristics that essentially prevent free rotation about the bond. A. True B. False. - correct answer ✔✔A Select the true statement: A. Multimeric proteins do not have quaternary structure B. Carbohydrates, lipids, nucleic acid, and proteins are polymeric macromolecules. C. Psi bonds are planar with little to no rotation around the bond. D. The chiral amino acids and proteins are D-stereoisomers - correct answer ✔✔B Select the true statement: A. The most for common elements in living organisms are oxygen carbon phosphorus and nitrogen. B. Peptide bonds form between the alpha carbon of one amino acid in the alpha amino nitrogen of another.

C. The process of transcription does not require a primer. D. None of the above. - correct answer ✔✔C Beta-mercaptoethanol disrupts disulfide bonds to denature proteins. A. True. B. False - correct answer ✔✔A

1. Which of the following is true? a. The four macromolecules found in biosystems are lipids, carbohydrates, proteins and nucleic acid. b. Lipids are not polymeric macromolecules. c. Nucleotides are joined by phosphodiester bonds to make nucleic acids. d. All the above are true. - correct answer ✔✔D
2. During the polymerization of nucleic acid which of the following does not occur? a. Nucleophilic attack by the 2'hydroxyl of the primer during DNA synthesis. b. Release of the 5' beta and gamma phosphates of the incoming nucleotide. c. Attack on the 5' alpha phosphate of the incoming nucleotide. d. All the above occur during the polymerization of nucleic acid. - correct answer ✔✔A
3. The affinity of adult hemoglobin and fetal hemoglobin differ with respect to oxygen and 2, 3-BPG. Which of the following correctly describes fetal and adult hemoglobin? a. Fetal hemoglobin has a higher affinity for 2, 3-BPG than adult hemoglobin. b. Fetal hemoglobin has a higher affinity for O2 than adult hemoglobin at the same partial pressure of O2. c. Both a and b are true. d. There is no true statement here. - correct answer ✔✔B
4. Which of the following sets of amino acids, read 1, 2, 3 from left to right contains amino acids that are classified as: 1) basic; 2) aromatic; and 3) aliphatic, branched

a. Arginine; Leucine; Methionine b. Lysine; Tryptophan; Leucine c. Asparagine; Phenylalanine; Serine d. None of the above. - correct answer ✔✔B

6. In methemoglobin, the central iron of the heme ring is in the 3+ oxidation state and there is CO bound to it. True False - correct answer ✔✔B
7. Select the true statement: a. Buffers are strong acids that can buffer a solution within one pH unit above and below the acid's pKa. b. The phosphate buffer system is the primary cellular buffer in our bodies. c. In an aqueous solution with a pH above the pKa of a weak acid, [HA] is greater than [A-]. d. The pH of a 0.1 M aqueous solution of acetic acid, a weak acid, is 1, and the pOH is 13. e. All the above are true. f. None of the above is true. - correct answer ✔✔B
8. Select the true statement: a. Peptide bonds are double bonds. b. The attributes of peptide bonds are due in part to the presence of two resonance structures in the amide bond. c. There is free rotation about peptide bonds that allow the peptide backbone to bend. d. Peptide bonds are formed between alpha carbons in adjacent amino acids. - correct answer ✔✔B
9. One reason that mutations in DNA sequence might not lead to a difference in amino acid sequence, is that some amino acids can be coded by more than one codon, and so a change in codon sequence may not result in a change of amino acid sequence. True False - correct answer ✔✔A
10. Select the true statement:

a. The most 4 common elements in living organisms are oxygen, carbon, sulfur, and phosphorus. b. The process of transcription does not require a primer. c. Beta-mercaptoethanol breaks peptide bonds to denature proteins. d. Ionic bonds are strongest when the atoms involved in the bond are linearly arranged. - correct answer ✔✔B

11. Select the true statement regarding occurrences in capillaries surrounding metabolically active tissues (red blood cells = RBCs): a. Cl- will be transported into RBCs. b. Hemoglobin will predominantly be in the relaxed state c. The pH of the blood will be slightly higher than in capillaries surrounding the lungs. d. CO2 will be primarily transported bound to the central heme iron. - correct answer ✔✔A
12. Given the following parameters solve for ∆G in kJ/mole. ∆H=20 kJ/mole, ∆S = 10 J/mole K, T= 298 K a. 22.98 c. 17.02 e. None of these is correct b. -22.98 d. -17.02 - correct answer ✔✔C
13. Some carbohydrates are macromolecules that can act as a fuel source, and others can provide structure to an organism. True False - correct answer ✔✔A
14. Select the true statement: a. Induced dipole-induced dipole interactions are generally stronger than ionic interactions under the same conditions of dielectric constant and distance. b. Van der Waals interactions are at their highest strength when the atoms are overlapping. c. For E, the Coulomb's Law is expressed in terms of energy in kJ per mole. d. All the above are true - correct answer ✔✔C

15. Identify the pH of an aqueous solution of acetic acid. The pKa of the acid is 4.5, and the molar concentrations are: [acetic acid] = 10 mM, [acetate] = 1 mM. a. pH= 2. b. pH= 3. c. pH= 5. d. pH = 6. e. The correct answer is not given. - correct answer ✔✔B
16. What is the pH of an aqueous solution of 0.01 nM HCl in water? a. It is approximately 3. b. It is approximately 11. c. It is approximately 7. d. The correct answer is not given. - correct answer ✔✔C
17. Translate the following fragment of DNA: CACGTATGG. (answers below are in one-letter amino acid code) a. GMC b. HVW c. GMW d. QVC e. None of these. - correct answer ✔✔B
18. Transcription has these characteristics EXCEPT a. Transcription requires a DNA template, which is read in the 3´to 5´ direction. b. Synthesized RNA is complementary to the DNA template used. c. Transcription requires a DNA primer. d. Transcription synthesizes the RNA chain in the 5´ to 3´ direction. - correct answer ✔✔C

19. For a reaction at constant pressure and volume, the Gibbs free energy equation answers thermodynamics questions like these EXCEPT: a. How much energy is released or required in this reaction? b. Will a specific reaction proceed in the forward direction without an input of energy? c. What is the rate of a specific reaction? d. What are the relative concentrations of the products and reactants at equilibrium? - correct answer ✔✔C
20. Which is true of The Second Law of Thermodynamics: a. The entropy of the universe is always 0. b. The energy of the universe always increases. c. The energy of the universe always decreases. d. None of these is true - correct answer ✔✔D
21. Choose the true statement: a. Chaperones often mask hydrophobic residues and cysteines to prevent misfolding. b. Heat shock proteins are chaperone proteins whose numbers tend to decrease during heat stress. c. When chaperones fail to refold proteins they can be tagged by nucleotides and sent to the proteasome. d. All the above are true. - correct answer ✔✔A
22. Covalent bond energy is equal to amount of energy released when a covalent bond is broken. a. True b. False - correct answer ✔✔B
23. Select the correct statement, considering eukaryotic processes. a. The genetic information in RNA is converted into DNA by translation. b. The genetic information in protein is converted to RNA by reverse transcription.

c. The genetic information in DNA is converted into RNA by transcription. d. The genetic information in RNA is converted into DNA by replication. - correct answer ✔✔C

4. Select the correct statement. In DNA: a. Base pairs are formed between adjacent nucleotides on the same DNA strand. b. The nucleotides are UACG c. Nucleotides have an OH group at the 2´position, rather than a hydrogen. d. None of the above is true. - correct answer ✔✔D
5. Which of the following is not a weak intermolecular interaction found in biological systems: a. Disulfide bond b. Hydrogen bond c. Van der Waals interaction d. All the above are weak intermolecular interactions. - correct answer ✔✔A
6. Choose the true statement: a. High concentrations of salts and metals like copper can denature proteins. b. Beta-sheets are stabilized by hydrogen bonds that are perpendicular to the strand. c. Beta-mercaptoethanol was used by Christian Anfinsen to break disulfide bonds. d. All the above are true. e. Only b and c are true. - correct answer ✔✔D
7. Which of the following is the major driving force in protein folding? a. Ionic interactions between alpha-helices and beta-sheets b. The entropic effect of water c. Electrostatic interactions between adjacent side chains in a peptide chain. d. Hydrogen-bonding between R-groups within domains - correct answer ✔✔B

8. Change in O2 affinity in hemoglobin is due to cooperativity, and results from allosteric changes in a monomer upon O2 binding that affects the tetramer as a whole. True False - correct answer ✔✔A
9. Please select the FALSE statement: a. Glycogen is more highly branched than starch. b. Glycogen is a storage form of glucose polymer that is found in animal tissues. c. The bonds linking sugars together to form carbohydrate polymers are called phosphoanhydride bonds. d. Cellulose and starch are both glucose polymers. - correct answer ✔✔C
10. Please solve for pKa [H2PO4-] = 100 mM, and [HPO42-]= 0.01 M, the pH of this solution is 6.2. The pKa of this acid = ___ a. 5.2, b. 7.2, c. 8.2, d. 11.2, e. 12.2, f. The correct value for pH is not here. - correct answer ✔✔B
11. What is FALSE regarding the genetic code. a. The genetic code is overlapping. b. The genetic code contains no space-holder "punctuation" between code words. c. The genetic code is degenerate. d. The number of codons representing each amino acid generally reflects the frequency of that amino acid's use in proteins. - correct answer ✔✔A
12. Choose the true statement: a. Anabolic pathways tend to release energy overall. b. Catabolic pathways break down larger molecules like proteins into smaller components. c. Catabolic reactions tend to be reducing, removing electrons from starting reactants. d. The synthesis of DNA describes a catabolic pathway. - correct answer ✔✔B
13. The presence of thymine in DNA rather than cytosine is one reason that DNA is more stable over time than RNA. True False - correct answer ✔✔B

18. Choose the true statement: a. The normal 3-dimensional structure of a single peptide chain is called its quaternary structure. b. Denaturing a protein disrupts its native conformation. c. A denatured protein can never regain its normal function upon refolding - once it's gone it's gone forever. d. Denaturing agents stabilize the three-dimensional structure of a protein. - correct answer ✔✔B
19. Choose the true statement: a. Amyloid can form when proteins misfold resulting in abnormal beta-sheet formation that encourages fibrillar organization. b. Amyloid fibrils tend to form parallel to the to the direction of the beta strands in the beta-sheet. c. Luckily, amyloid fibrils are generally unstable and are prone to degradation by proteases and heat. d. All the above are true. - correct answer ✔✔A
20. Choose the true statement: a. Proline is a conservative substitution for serine. b. Cysteine is a conservative substitution for methionine. c. Arginine is a conservative substitution for glutamine. d. Glycine is a conservative substitution for valine. - correct answer ✔✔C
21. Your enzyme works best at a pH of 5.3. What is the BEST buffer for this enzyme? a. Buffer A: pK1= 3.4, pK2 = 6.9, and pK3 = 12. b. Buffer B: pK1= 5.4, pK2 = 6. c. Buffer C: pK1= 4.3, pK2 = 7. d. Buffer D: pK1= 3.9, pK2 = 6.4, and pK3 = 11.1 - correct answer ✔✔B
22. You are walking to class - which of these reactions would predominate in RBCs in the capillaries in your muscles? a. H2CO3 H2O + CO b. H2O + CO2 H2CO

c. Both would be proceeding equally. d. Neither would occur. - correct answer ✔✔B

23. Which of the following is FALSE? a. The primary form of hemoglobin found in adults includes 2 alpha-globin and 2 beta-globin chains. b. Before birth, adult hemoglobin replaces fetal hemoglobin to ready the baby for life outside the womb. c. Sickle-cell trait (HbS) can be protective in persons heterozygous for this trait, as it reduces death rates from malaria. d. In sickle cell crisis, mutant hemoglobin forms fibrillar structures that deform red blood cells. - correct answer ✔✔B Please choose the best answer for each question.
24. Which of the following is true? a. DNA is used as the template during transcription. b. RNA is used as a template during the transcription of protein. c. dGTP and GTP differ at the 3' position, as dGTP is reduced at this position while GTP is not. d. All the above are true e. Only b and c are true - correct answer ✔✔A
25. Which of the following, regarding lipids, is FALSE? a. Lipids are largely polar in nature. b. Cell membranes are largely made up of lipids and protein. c. Lipids can provide structure. d. Lipids can act as signaling molecules. - correct answer ✔✔A
26. Which of the following is FALSE? a. Proteins are polymers of amino acids joined together by peptide bonds. b. In the lipid bilayer, lipids are held together by covalent bonds to form the lipid membrane. 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, while non- polar amino acids are generally buried inside the protein, away from the aqueous solution. - correct answer ✔✔B

4. Identify the hydrogen bond acceptor in the figure below: O1 H1 O O--H |||||||||| O a. O 1 b. H 1 c. O 2 - correct answer ✔✔C
5. 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. Carbon-carbon double bonds are generally longer and have less bond energy than do carbon-carbon triple bonds. d. All the above are true e. Only a. and b. are true - correct answer ✔✔D
6. Select the true 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. e. Only b and c are true. - correct answer ✔✔C
7. Please select the true statement:

a. In metabolically active tissues, CO2 is used to produce oxygen in a reaction catalyzed by carbonic anhydrase. b. The concentration of carbon dioxide is lower in metabolically active tissues than in the lungs. c. The heme ring is entirely non-polar in nature. d. Hemoglobin in the tense state has a lower affinity for oxygen than hemoglobin in the relaxed state. - correct answer ✔✔D

8. Proline does not have chiral stereochemistry at the alpha carbon, because it is an imino acid. a. True b. False - correct answer ✔✔B
9. Please select the TRUE statement, for a solution in water under standard conditions: a. The pH of a 0.1 M solution of the strong base, KOH is 1 b. The pH of a 0.01 nM solution of the strong base, KOH is 11 c. The pH of a 0.1 M slution of acetic acid, a weak acid, is 1 d. None of the answers, a-c is correct. - correct answer ✔✔D
10. Please select the TRUE statement: a. The globin polypeptide is primarily beta sheet. b. Hemoglobin functions as a tetramer and shows allosteric binding kinetics. c. The prosthetic group of deoxyhemoglobin includes an iron ion which is in the 3+ oxidation state d. The function of myoglobin is to store oxygen in the muscles. e. All of the above are true. f. Only b, c, and d are true. g. Only b and d are true. - correct answer ✔✔G
11. Please select the TRUE statement: a. Adult hemoglobin becomes the predominant form of hemoglobin shortly before birth. b. Super-oxide is O2-

c. Fetal hemoglobin is α2β2 tetramer. d. At high pCO2, hemoglobin has a greater affinity for oxygen than when at low pCO2. - correct answer ✔✔B

12. Please solve for pH if the pKa of the acid is 9 and the concentrations of acetic acid is 1 mM and the concentration of Acetate is 100 mM. a. pH= 9. b. pH= 11 c. pH= 7 d. pH = 7. e. The correct answer is not given - correct answer ✔✔B
13. Please identify the TRUE statement regarding water: a. The bulk of water is ionized in solution. (Water molecules are predominantly found in the ionized state.) b. The conjugate base of water is H30+ c. Water is permanent dipole with partial charges at the oxygen and each of the hydrogen atoms d. Water is non-polar - correct answer ✔✔C
14. Choose the FALSE statement: a. Peptide bonds covalently link the alpha-carboxyl group of one amino acid to the alpha-amino group of another amino acid. b. The four major groups of macromolecules are nucleic acid, protein, lipids and carbohydrates c. Acids are proton donors, bases are proton acceptors d. The entropy of the universe is constant. - correct answer ✔✔D
15. Based on the pKa values of side chains at pH 7, which of these tri-peptides contains, from N'- to C'- terminus, neutral - basic - acidic residues? a. Ile-Arg-Lys b. Val-Lys-Asn

c. Asp-Arg-Val d. Gly-Lys-Glu e. Met-Arg-Gly - correct answer ✔✔D

16. Please select the *FALSE * answer: a. A covalent bond between two carbon atoms has a higher bond energy than the van der Waals interactions between two hydrogen atoms. b. Ionic bonds are non-directional. c. Hydrogen bonds are stronger when all of the atoms involved in the bond are in a linear orientation with respect to one another. d. Hydrogen bonds among small molecule solutes in hexane, are weaker than hydrogen bonds between these same solutes in water. - correct answer ✔✔D
17. Please select the TRUE statement: a. The four elements at the highest mole percent in humans are H, C, N, O b. Amino acids in living organisms are in the D-configuration c. When proteins are comprised of single peptide chains, they are said to have secondary structure, but they do not have tertiary structure; the term tertiary structure is reserved for multimeric proteins only. d. The term motif refers to the interactions between domains to form a functional tertiary structure. - correct answer ✔✔A
18. Select the TRUE 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. - correct answer ✔✔B
19. The amino acid sequence of a yeast protein is 60% identical to its human homolog. The DNA sequences of the genes that encode these two proteins, however, are only 45% identical. How can this be?

a. Mutations leading to differences in DNA sequence might not lead to differences in amino acid sequence, because the genetic code is overlapping. b. The genetic code is degenerate. c. DNA is often mutated by radiation, while proteins are more stable. d. There are more stringent selection pressures on maintaining the correct amino acid sequence than DNA sequence, as changes in amino acid sequence often result in loss of function, while changes in DNA sequence might not result in a change in protein function. e. All the above are true. f. Only b and d are true. g. All but c are true. - correct answer ✔✔F

20. Choose the FALSE statement regarding alpha helices a. Alpha helices are held in position by hydrogen bonds between main chain atoms. b. Alpha helices are ordered with amino acid R-groups projecting outward from the helix. c. Prolines are amino acids commonly found throughout the length of alpha helices. d. Stabilizing hydrogen bonds are parallel to the axis of the helix and are formed between amino acids that are 3 to 4 residues apart. - correct answer ✔✔C
21. Select the FALSE 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 in part on the proximity of the ions. e. Ionic interactions are stronger between charged molecules in non-polar solvents. - correct answer ✔✔C
22. Translate this partial sequence: 5' ATGAGTGAGATT 3' 3' TACTCACTCTAA 5' a. Met, Ser, Glu, Leu

b. AUGAGTGAGAUU c. Met, Ser, Glu, Ile d. UACUCACUCUAA e. Tyr,Ser,Leu,Stop - correct answer ✔✔C

24. tRNA is an adapter RNA that covalently binds to amino acids and hydrogen bonds with codons in the RNA template True False - correct answer ✔✔A
25. Select the FALSE statement regarding weak forces: a. Buffers are weak acids that buffer most effectively at the pKa of the acid, but can buffer within one pH unit above and below the acid's pKa. b. At the pKa of an acid, the acid and its conjugate base are at equimolar concentrations. c. The phosphate buffer system is the primary blood buffer in our bodies. d. Free amino acids can function as buffers. - correct answer ✔✔C
26. If the molar concentration of a product increases relative to molar concentration of the starting reactants, this will have what effect on the free energy of the reaction? e. No effect whatsoever. f. It will cause ∆G to increase. g. It will cause ∆G to decrease. h. It will cause the reaction to become more favorable. i. Only b and d are true. j. Only c and d are true. - correct answer ✔✔F
27. Chimp myoglobin and human myoglobin represent protein paralogs. a) True, b) False - correct answer ✔✔B
28. The distal histidine in hemoglobin is a coordination point for the heme central iron. a) True, b) False - correct answer ✔✔B

29. Nucleotides are held together in the nucleic acid polymer by covalent phosphodiester bonds. a) True, b) False - correct answer ✔✔A
30. Catabolic pathways are largely divergent, oxidizing and exergonic overall. a) True, b) False - correct answer ✔✔A

1. Which of the following is NOT one of the 4 classes of macromolecules: a) proteins b) nucleic acids c) vitamins d) lipids - correct answer ✔✔C
2. The enzyme used in your experiment has an optimal of pH of 6.3. You must choose a buffer to use during your experiment. Which of the buffers below will you use? a) Buffer A: pKa = 7. b) Buffer B: pKa = 4. c) Buffer C: pKa1 = 4.8, pKa2 = 8. d) Buffer D: pKa1 = 3.8, pKa2 = 7. e) Buffer E: pKa1 = 2.8, pKa2 =5.8 - correct answer ✔✔E
3. Please select the FALSE statement: a) The four most prevalent elements in biosystems, in random order, are. H,O,N,C. b) The chiral amino acids found in biosystems are D-stereoisomers. c) Hydrogen bonds are weaker than covalent bonds. d) The strength of ionic bonds is inversely proportional to the dielectric constant of the solvent. - correct answer ✔✔B
4. Please select the true statement: a) A peptide bond is a covalent bond formed between the alpha-carboxyl group of one amino acid the alpha-carbon group of another amino acid.

b) Peptide bonds have partial double bond characteristics, which limit the rotation about this bond. c) Peptide bonds are ester bonds. d) Hydrogen bonding between R-groups of amino acids gives rise to protein secondary structure. e) Only c) and d) are true. - correct answer ✔✔B

5. Please select the true statement: a) One definition of an acid and a base is that an acid is a proton acceptor, and a base is a proton donor. b) CO2 combines with H2O to form carbonic acid, which deprotonates to form carbamate. c) The primary intracellular buffer is the phosphate buffering system. d) The primary means of CO2 transport in the body is as dissolved CO2 in the blood. - correct answer ✔✔C
6. Please select the true statement: a) Van der Waals attractive forces become stronger as two atoms or groups approach each other, until they reach the limit of their Van der Waals radii. b) When ∆G for a reaction is greater than zero, the reaction will proceed in the forward direction. c) HCl and KOH dissociate incompletely in aqueous solution, such that the concentrations of protonated and deprotonated acid is dependent on the pH of the solution. d) When ∆G for a reaction is zero, the reaction proceeds in the reverse direction. - correct answer ✔✔A
7. Please select the true statement: a) The α2β2 tetramer becomes the predominant form of hemoglobin shortly before birth.. b) The affinity of CO for hemoglobin is higher than the affinity of O2 for hemoglobin under the same conditions. c) Lowering of blood pH increases the oxygen affinity of hemoglobin d) In metabolically active tissues, CO2 is used to produce oxygen in a reaction catalyzed by carbonic anhydrase. - correct answer ✔✔B
8. Hydrogen bonds are strongest when the hydrogen donor, the hydrogen atom and the hydrogen acceptor all lie in a straight line. a) True

b) False - correct answer ✔✔A

9. In regard to alpha helices, hydrogen bonds that stabilize this structure are parallel to the axis of the helix and are formed between amino acids that are 3 to 4 residues apart. a) True b) False - correct answer ✔✔A
10. The small molecule 2,3-BPG is a poly-anionic small molecule that binds to histidine residues in hemoglobin. a) True b) False - correct answer ✔✔A
11. Please select the true statement: a) Alpha helices in most proteins are left-handed. b) A beta-turn is a secondary structural element representing a sharp turn that changes the direction of a peptide strand. c) The oxidation state of methemoglobin is 2+, which prevents O2 binding. d) The total energy of a system and its surroundings must increase for a reaction to be favorable. - correct answer ✔✔B
12. Please select the FALSE statement: a) Glycogen is a storage form of glucose polymer that is found in animal tissues. b) Hydrogen bonding is greater in glycogen and starch than it is in cellulose and chitin. c) The bonds linking sugars together to form carbohydrate polymers are called glycosidic bonds. d) Cellulose and starch are both glucose polymers. e) Glycogen is more highly branched than starch. - correct answer ✔✔B
13. Please select the true statement: a) Interactions between amino acid side chains determine whether any two given amino acids residues will form a peptide bond.

b) Valine and methionine are hydrophobic, branched chain amino acids. c) Tryptophan, tyrosine, and phenylalanine are aromatic amino acids d) There are no true answer here. - correct answer ✔✔C

14. Please select the true statement: a) The small amino acid, glycine is one of the most commonly substituted amino acids. b) Protein domains are another name for motifs. c) The myoglobin protein is made of four homologous monomers. d) The pH of blood in the tissues favors the tense state of hemoglobin. e) Only a and d are true. - correct answer ✔✔D
15. Please select the true statement: a) The myoglobin and hemoglobin of humans are orthologs b) Leghemoglobin and human myoglobin are orthologs. c) The distal histidine is a coordination site for iron in the heme prosthetic group in myoglobin and hemoglobin. d) All the above are true e) Only b and c are true - correct answer ✔✔B
16. Which of the following is true? a) In a polar solution like water, hydrophobic amino acids will be more likely to be found buried in the interior of the protein rather than at the surface of the protein, facing the solvent. b) In a non-polar environment, like a membrane, hydrophobic amino acids will be more likely to be found buried in the protein rather than on the surface, facing the non-polar environment. c) Both a and b are true. d) Neither a nor b are true. - correct answer ✔✔A
17. Which of the following sets of amino acids, left to right are hydrophobic, aromatic and basic? a) Valine; Lysine; Aspartic acid b) Lysine; Tryptophan; Asparagine

c) Isoleucine; Phenylalanine; Lysine d) Leucine: Tryptophan; Valine - correct answer ✔✔C

18. During the process of transcription The RNA template is read in the 5´-3´direction. a) True b) False - correct answer ✔✔B
19. Select the true statement regarding weak buffers: a) Buffers are comprised of strong acids in aqueous solution. b) At the pKa of an acid, the protonated, acidic form of the acid predominates. c) Below the pKa of an acid, the conjugate base predominates. d) There are no true answers here. - correct answer ✔✔D
20. Select the true statement: a) tRNA is an RNA template that encodes the protein sequence. b) rRNA is an adapter RNA that covalently binds to amino acids and hydrogen bonds with codons in the RNA template. c) Mutations leading to differences in DNA sequence might not lead to differences in amino acid sequence, because the genetic code is degenerate d) Eukaryotic messenger RNAs, when reverse-transcribed, will yield DNA that is identical to the genomic DNA sequence for that RNA. e) Only c and d are true. - correct answer ✔✔C
21. Which of the following is true? a) The highest order of structure seen in myoglobin is secondary structure. b) The highest order of structure of hemoglobin is tertiary structure. c) The primary and tertiary structures of beta-globin and myoglobin show high degrees of homology. d) All of the above are true. - correct answer ✔✔C
22. Which of the following is true? Please note that RNAse A and actin are homologous proteins.

a) Chimp RNAse A and chimp actin are both orthologs, and paralogs. b) Chimp RNAse A and chimp actin are paralogs, and not orthologs. c) Chimp RNAse A and Human RNAse A are both paralogs, and orthologs. d) Chimp RNAse A and Human RNAse A are paralogs, not orthologs. - correct answer ✔✔B

23. Select the true statement. a) Ionic interactions are stronger between charged molecules in non-polar than in polar solvents. b) Ionic interactions are attractive or repulsive forces between atoms with a full formal charge. c) The strength of an ionic interaction is directly proportional to the distance, r, between the ions. d) All the above are true e) Only a, and b are true. - correct answer ✔✔E
24. What is he pH of an aqueous solution of acetic acid when the pKa of the acid is 6.5, and the molar concentrations are: [acetic acid] = 10 mM, [acetate] = 0.1 M. a) pH= 3.5 b) pH= 8.5 c) pH= 7.5 d) pH = 4.5 e) The correct answer is not given. - correct answer ✔✔C
25. The 6 coordination sites of the iron in heme are the 4 pyrrole nitrogens, & distal and proximal histidines. True False - correct answer ✔✔B
26. Please select the true statement. a) The normal 3-dimensional structure of a protein is called its native state, or native conformation. b) A denatured protein is one that retains its native conformation, but is expressed at an unnatural time or place. c) Denatured proteins generally retain their normal function. d) Denaturing agents are chemicals or processes that disrupt the primary structure of a protein. - correct answer ✔✔A

27. Please select the true statement. a) Amyloid is an insoluble aggregate of protein deposited in tissues. b) The proteins that make up an amyloid deposit are generally misfolded. c) To form an amyloid fiber, abnormal prions generally align themselves to form a continuous beta-sheet. d) All the above are true e) Only a) and b) are true. - correct answer ✔✔D
28. What is the pH of an aqueous solution of 0.01 nM HCl in water? a) It is approximately 1. b) It is approximately 13. c) It is approximately 7. d) The correct answer is not given. - correct answer ✔✔C
29. Heating beef tainted with "mad cow disease", bovine spongiform encephalitis, eliminates the prions responsible for Creutzfeldt-Jakob Disease. A. True B. False - correct answer ✔✔B
30. Please select the FALSE statement. a) Ubiquitin is a tag that identifies proteins to be brought to the proteasome. b) The actual breaking of the peptide bonds of proteins by the proteasome is not done with ATP hydrolysis. c) Chaperones can limit regions available for intermolecular interaction, by masking certain regions of the protein, such as cysteine residues. d) Beta-mercaptoethanol breaks peptide bonds to denature proteins. - correct answer ✔✔D

1. Please identify the function of the proximal histidine in hemoglobin function:

a. This amino acid provides steric hindrance for the entry of CO into the heme oxygen-binding pocket. b. This amino acid makes a hydrogen bond to O2 that is bound to iron, which is in the heme ring. c. This amino acid is a coordination site for the iron, which is in the heme ring. d. Only a, and b are true e. Only a, b, and c are true. - correct answer ✔✔C

2. Please choose the true statement: a. The R-group of serine causes it to be a non-polar amino acid. b. Glycine is a hydrophobic amino acid. c. The histidine R-group can act like a base under physiologic conditions. d. The asparagine R-group can act as an acid under physiologic conditions. - correct answer ✔✔C
3. If a reaction A+B <-> C+D has a ∆G˚ of +34.30 Joules per mole, which of the following is true? a. This reaction is thermodynamically favorable in the forward direction. b. The ∆G˚ of C+D <-> A+B = -34.30 Joules per mole. c. The reaction A+B <->C+D is not at equilibrium. d. The reaction A+B <-> C+D is exergonic. e. All the above are true. f. Only b and c are true. g. Only b and d are true. - correct answer ✔✔F
4. Given a reaction, A+B <-> C+D, if the concentrations of C & D increased relative to the concentrations of A & B, what will be the most likely effect on the thermodynamics of the reaction A+B<-> C+D? a. There would be no effect on the thermodynamics. b. ∆G would decrease. c. ∆G would increase. d. The concentrations of products or reactants have no relevance to thermodynamics. - correct answer ✔✔C

5. Given the reaction A+B <-> C+D above with a ∆G˚ of +34.30 Joules per mole, if this reaction were coupled with another reaction, E+F <-> C +D with a ∆G˚ of +40.50 Joules per mole, which of the following is true? a. The reaction A + B <-> E+F has a ∆G˚ of +74.80 Joules per mole. b. The reaction A + B <-> E+F is unfavorable in the forward direction. c. The reaction A + B <-> E+F has a ∆G˚ of -6.20 Joules per mole. d. The reaction A + B <-> E+F is favorable in the forward direction. e. Only a and b are true. f. Only c and d are true. - correct answer ✔✔F
6. Which of the following is true? a. In a polar solution like water, hydrophobic amino acids will be more likely to be found buried in the interior of the protein rather than at the surface of the protein, facing the solvent. b. In a non-polar environment, like a membrane, hydrophobic amino acids will be more likely to be found buried in the protein rather than on the surface, facing the non-polar environment. c. Both a and b are true. d. Neither a nor b are true. - correct answer ✔✔A
7. The energy of attraction or repulsion of an ion pair is inversely proportional to the product of the charges of the ions. a. True b. False - correct answer ✔✔B
8. In regard to alpha helices, hydrogen bonds that stabilize this structure are parallel to the axis of the helix and are formed between amino acids that are 3 to 4 residues apart. a. True b. False - correct answer ✔✔A
9. The small molecule 2,3,BPG binds to histidine residues in hemoglobin, and binds more tightly to adult hemoglobin than fetal hemoglobin. a. True