BIOC 384 FINAL FULL SET
RNA only contains which of the following bases? -thymine -adenine -uracil -guanine
uracil
Which linear sequence of bonded atoms can be found in the backbone of polypeptides? - C-N-N-C - C-C-N-C - N-C-C-C - C-O-C-N
- C-C-N-C
If the isoelectric point (pl) for an amino acid is at point A, what is the charge on the amino acid at point B? - 0 - -2 - +2 - -1 (graph is increasing like stairs)
-2
Chargaff's rule is that the amount of -A = G and the amount of C = T. -A = C = G = T. -A = T and the amount of C = G. -A = c and the amount of G = T.
-A = T and the amount of C = G.
Which of the following is true? -A neutral solution contains [H2O] = [H+]. -A neutral solution does not contain any H+ or OH-. -An acidic solution has [H+] > [OH-]. -A basic solution does not contain H+.
-An acidic solution has [H+] > [OH-].
A common database tool used to determine homologous genomic sequences is called -the National Center for Biotechnology Information -the National Human Genome Research Institute -Computational Analysis -Basic Local Alignment Search Tool
-Basic Local Alignment Search Tool
What side products of pyruvate are being converted into alcohol and carbon dioxide by yeast? -CO and NADH -CO2 and NADH -CO2 and NAD+ -CO and NAD+
-CO2 and NAD+
What process converts DNA to RNA? -DNA transcription -DNA replication -DNA translation -RNA transcription
-DNA transcription
Which of the following statements about the chamber-type chaperone protein GroEL-GroES is correct? -GroEL-GroES requires the hydrolysis of multiple ATPs to assist in the folding of a protein. -GroEl-GroES recycles misfolded proteins by recovering individual amino acids. -GroEL-GroES assists in protein unfolding by hydrolyzing and remaking the protein peptide bonds. -GroEL-GroES uses GroEL as a cap, trapping an unfolded protein in the GroES chamber.
-GroEL-GroES requires the hydrolysis of multiple ATPs to assist in the folding of a protein.
In the Anfinsen experiment with the unfolding of RNaseA, what order could the chemical reagents be removed in order to achieve an inactive protein? -Remove denaturant first and reductant second. -Simultaneously remove denaturant and reductant. -Remove reductant first, denaturant second, and then finally add back reductant. -Remove reductant first and denaturant second.
-Remove reductant first and denaturant second.
Which of the following statements is true about alpha-helices? -The center of the helix is an open channel. -There are about seven amino acids per helical turn. -The amide backbone dipoles line up in one direction. -The helical backbone structure is stabilized by ionic interactions.
-The amide backbone dipoles line up in one direction.
The oxidation of glucose releases 15.7 kJ/g. Is this reaction spontaneous? -Yes, because it is exothermic. -No, because it is exothermic. -Yes, because it is endothermic. -The answer cannot be determined.
-The answer cannot be determined.
Which of the following statements about beta-sheet structures is true? -The individual strands of all beta-street structures are connected by turns, helices, or loops. -All amino acid side chains in antiparallel and parallel beta-sheet structures point to one side of the sheet. -Parallel beta-sheet structures have backbone amides that directly hydrogen bond between strands, whereas antiparallel beta-sheets have hydrogen bonds that are offset. -All beta-sheet structures form a spiraling backbone chain.
-The individual strands of all beta-street structures are connected by turns, helices, or loops.
Using the figure below, which of the following best describes the titration curve? -The equivalence point for the titration is pH = 7. -The midpoint of the titration is pH = 7. -The pKa for this weak acid is 4.76. -This is a titration of a weak base by NaOH.
-The pKa for this weak acid is 4.76.
What is a current hypothesis that explains the infectious nature of prion diseases? -The virus responsible for prion diseases is transmissible. -Unfavorable environmental factors negatively influence healthy cells. -The small molecule denaturants found in infected cells are passed on to healthy cells. -The presence of an improperly folded prion protein promotes the misfolding of normal prion proteins.
-The presence of an improperly folded prion protein promotes the misfolding of normal prion proteins.
What is the difference between clamp-type and chamber-type chaperone proteins? -One uses ATP and the other does not. -One folds proteins, whereas the other just protects them from unfolding. -They are shaped differently. -One type is found extracellularly and one intracellularly.
-They are shaped differently.
Which of the following statements about alpha-helices and beta-sheets are FALSE? -They are both incompatible with the amino acid proline. -They both interact with other protein elements through amino acid side chains that stick out. -They both contain a recurring pattern of hydrogen bonds from one peptide bond to another peptide bond. -They both give rise to similar tertiary structures.
-They both give rise to similar tertiary structures.
Which of the following best defines the first law of thermodynamics? -All spontaneous processes in the universe tend toward dispersal of energy -Total amount of energy in the universe is a constant -There is no entropy at zero Kelvin -Entropy is a measure of disorder
-Total amount of energy in the universe is a constant
The common protein fold shown below is the _________ fold. -Greek key -Rossman -FERM domain -alpha/beta barrel
-alpha/beta barrel
A polypeptide has a high pl value. Which amino acids might comprise it? -arginine and lysine residues -aspartate and glutamate residues -the large nonpolar amino acids -a mixture of aspartate and arginine residues
-arginine and lysine residues
At what point does the isoelectric point or pl occur? -when all of the acidic protons are neutralized with base -at pH = 7.0 -at the pH when all negative charges on a zwitterion counter the positive charges -when the molecule has a single electric charge
-at the pH when all negative charges on a zwitterion counter the positive charges
In viral transduction, DNA is transferred when -bacteriophages infect bacteria. -foreign DNA fragments are inserted into the plasmid using multiple cloning sites. -there is a horizontal gene transfer during the bacteria mating process. -a dead bacterium releases DNA into the environment and it is obtained by another bacterium.
-bacteriophages infect bacteria.
Increasing the ion concentration increases the Tm because the ions -bind to the phosphate groups of the DNA backbone and increase stability. -bind to the nucleic acids and disrupt the base pairs, decreasing stability. -increase the base length of the DNA, increasing stability. -associate with the ribose sugars, decreasing stability.
-bind to the phosphate groups of the DNA backbone and increase stability.
Pyruvate decarboxylase converts pyruvate into -carbon dioxide and acetaldehyde -carbon monoxide and acetaldehyde -water and glucose -ethanol and carbon dioxide
-carbon dioxide and acetaldehyde
The appearance of new gene speciation is an example of -gene multiplication -gene singulation -gene duplication -random mutation
-gene singulation
The exons of a single gene often encode for different functional domains of a protein, which can result in -genetic recombination -gene regulation -untranslated regions -termination of transcription
-genetic recombination
An inherited disease comes from the mutation of DNA in a ______ cell. -somatic -germ-line -adipose -blood
-germ-line
The characteristic(s) of a phospholipid is/are that they -are overall nonpolar. -have a polar charged head group and nonpolar hydrocarbon tails. -have a nonpolar head group and polar hydrocarbon tails. -are overall polar.
-have a polar charged head group and nonpolar hydrocarbon tails.
The protein that binds to DNA in a sequence-independent manner are -histones -single-stranded binding proteins -Lac repressor proteins -histones and single-stranded binding proteins
-histones and single-stranded binding proteins
Protein secondary structures such as alpha-helices and beta-sheets are stabilized mainly by -ionic interactions. -disulfide bond formation. -van der Waals forces. -hydrogen bond formation.
-hydrogen bond formation.
If a plasma membrane is hydrophobic, what kinds of amino acids are MOST likely to be found in the membrane? -hydrophilic amino acids -hydrophobic amino acids -polar amino acids -charged amino acids
-hydrophobic amino acids
As a protein folds, what are the stabilizing forces that help keep the protein folded? -hydrophilic amino acids on the interior and hydrophobic amino acids on the exterior -increase in entropy in the surrounding water -favorable change in free energy -hydrophobic amino acids on the interior and hydrophilic amino acids on the exterior
-hydrophobic amino acids on the interior and hydrophilic amino acids on the exterior
Organisms on Earth cannot easily exist at temperatures below 0 degrees C because at that temperature -hydrogen bonds cannot exist. -water does not exist in a tetrahedron. -ice crystals form in the organism. -proton hopping cannot occur.
-ice crystals form in the organism.
The points in the Ramachandran plot are derived by -counting the number of amino acids and placing points in allowed regions -measuring the o and y angles in an experimentally determined protein crystal structure -placing each amino acid in regions commonly occupied by that amino acid -experimentally measuring the optical rotation of polarized light
-measuring the o and y angles in an experimentally determined protein crystal structure
In isoelectric focusing, a protein with a pH below the pI would -migrate toward the anode. -migrate toward the cathode. -stop migrating. -migrate, but there is no way to determine the direction.
-migrate toward the anode.
A double helix that crosses itself in a right-handed twist is referred to as a -positive supercoil -negative supercoil -topoisomer -linking number
-negative supercoil
In isoelectric focusing, -negatively charged proteins migrate toward the cathode. -negatively charged proteins migrate toward the anode. -small proteins migrate the fastest. -large proteins migrate the fastest.
-negatively charged proteins migrate toward the cathode.
Energy conversion in living systems is required for what three types of work? -osmotic work, chemical work, mechanical work -osmotic work, chemical work, potential work -kinetic work, chemical work, mechanical work -osmotic work, photosynthetic work, mechanical work
-osmotic work, chemical work, mechanical work
What is another way to describe the amphipathic nature of a fatty acid? -polar head and nonpolar tail -nonpolar head and polar tail -polar head and double bonds in tail -nonpolar head and double bonds in tail
-polar head and nonpolar tail
Energy conversion in a biological system operates under constant _______ and constant _______. -heat; pressure -work; heat -pressure; volume -volume; heat
-pressure; volume
How do plants, fungi, and bacteria avoid the damaging effects of a hypotonic environment? -flexible cell walls -rigid cell walls -semipermeable cell walls -photosynthesis
-rigid cell walls
Osmosis occurs when water diffuses through a -semipermeable membrane from high water to low water concentration. -nonpermeable membrane from high water to low water concentration. -semipermeable membrane from low water to high water concentration. -semipermeable membrane from high solute to low solute concentration.
-semipermeable membrane from high water to low water concentration.
Which method uses mass to charge ratios as well as a bioinformatics approach to determine the amino acid composition of a protein? -X-ray crystallography -nuclear magnetic resonance -tandem mass spectrometry -size exclusion chromatography
-tandem mass spectrometry
The dipole moment associated with a peptide bond proceeds from which amide? -the C to the O atom -the C to the N atom -the O to the H atom -the H to the O atom
-the H to the O atom
In a hydrogen bond between a water molecule and another water molecule, -a hydrogen ion on the water molecule forms an ionic bond with the oxygen ion on the other water. -the hydrogen bond typically forms between the oxygen atom of the water and the hydrogen on the other water. -a hydrogen on the water molecule forms a covalent bond to a hydrogen atom on the other water. -the hydrogen atom forms an ionic bond with a carbon on the other water.
-the hydrogen bond typically forms between the oxygen atom of the water and the hydrogen on the other water.
Triaglycerols are neutral molecules made of -three fatty acid esters covalently linked to glycine -three fatty acid esters covalently linked to glycerol -two fatty acid esters covalently linked to glycine -three acyls covalently linked to glycerol
-three fatty acid esters covalently linked to glycerol
The combustion of gasoline is considered exothermic because heat is -transferred from the surroundings to the system. -transferred from the system to the surroundings. -transferred to the universe. -not transferred.
-transferred from the system to the surroundings.
The amino acid sequence of a protein determines its structure. Which of the following statements is true? -two proteins with similar amino acid sequence should have similar structures -two proteins with different amino acid sequences will have identical structures -two proteins with similar amino acid sequences will always have the same function in a cell -it is impossible to determine how proteins will fold based on the amino acid sequence alone
-two proteins with similar amino acid sequence should have similar structures
Christian Anfinsen showed in a famous experiment that it is possible to unfold a protein and refold it to obtain a functional protein. Which two reagents were used in this experiment to unfold the protein? -detergent and salt -urea and beta-mercaptoethanol -acid and base -ethanol and beta-mercaptoethanol
-urea and beta-mercaptoethanol
The interaction between nonpolar molecules is best characterized as -a hydrogen bond -ionic interactions -van der Waals interactions -a covalent bond
-van der Waals interactions
The proposal that DNA is a double helix was based on what experimental evidence? -NMR -IR -HPLC -x-ray crystallography
-x-ray crystallography
Which of the following is the Kw value for pure water at 25 degrees C? - 1 x 10^14 - 1 x 10^-14 - 7 - 14
1 x 10^-14
After centrifugation, there is a 10% decrease in activity and a 75% decrease in total protein. What is purification of the target protein? - 0.28 fold - 1.3 fold - 3.6 fold - 7.5 fold
3.6 fold
Calculate the concentration of pH of a 0.023 M HCl solution. - 12.36 - 3.68 - 1.64 - 2.30
1.64
Consider the whole amino acid alanine at pH = 7. How many atoms (including Hs) are found in the molecule? -15 -13 -10 -8
13
What is the concentration of H+ in a solution of 0.05 M NaOH? - 5 x 10^-16 M - 2 x 10^-13 M - 5 x 10^12 M - 140 M
2 x 10^-13 M
What is the pl of the dipeptide shown? (Use the pK as given.) - 0 - 5 - 9 - 10.5
5
Calculate the linking number for a B-DNA strand that contains 735 total base pairs. -50 -61 -67 -70
70
Given 80 grams of water, how many calories are required to raise the temperature 1 degree C? -4.184 calories -15.7 calories -80 calories -Not enough information is given to calculate the answer.
80 calories
Calculate the specific activity when 500 mg of protein has an activity of 18,000 units. - 0.28 units/mg protein - 36 units/mg protein - 9,000 units/mg protein - 13,000 units/mg protein
9,000 units/mg protein
Which of the following peptides would be eluted last when separated using gel filtration chromatography? - A --> 360 g/mol, -2 charge - B --> 1080 g/mol, -1 charge - C --> 1800 g/mol, 0 charge - D --> 1440 g/mol, +1 charge
A --> 360 g/mol, -2 charge (smallest)
The DNA double helix is considered to be a _______ structure. -primary -secondary -tertiary -quaternary
secondary
A solution of which of the following would be a good buffer system? -HCl and NaOH -HCl and H2O -CH3COOH and NaCH3COO -NaOH and KOH
CH3COOH and NaCH3COO
Which of the following is NOT a common functional group? -COOH -CH3 -SH -CHO
CHO
The figure below shows part of the primary structure of DNA. Identify the nucleotide. -A -B -C -D
D
The following peptides are separated using an anion exchange resin in ion-exchange chromatography. Which peptide is eluted first? - A --> 360 g/mol, -2 charge - B --> 1080 g/mol, -1 charge - C --> 1800 g/mol, 0 charge - D --> 1440 g/mol, +1 charge
D --> 1440 g/mol, +1 charge (most positive)
The RNA world model is based on the hypothesis that ______ is stable. -RNA -DNA -uracil -adenine
DNA
Which technique ionizes polypeptides by releasing them from a small metallic capillary at high voltage? -ESI -MALDI -NMR -X-ray crystallography
ESI
In the second temperature phase of PCR, why does the temperature vary from 55 degrees C to 65 degrees C? -different ionic strengths -different primer concentrations -G-C content -different amount of hydrogen bonds
G-C content
Which amino acid side chain from the list below is the most polar? -Gln -Ala -Leu -Phe
Gln
Weak acids have a high pKa because the -HA concentration is high. -H+ concentration is high. -A- concentration is high. -HA concentration is low.
HA concentration is high.
The chirality of naturally occurring amino acids in proteins is -R -L -D -the same as glyceraldehyde.
L
Predict how type I topoisomerases change the supercoil region. - Lk = 2 - Lk = 1 - Lk = -1 - Lk = -2
Lk = -1
Which of the following expresses the relationship among the linking number, twist, and writhe? -Tw = Lk + Wr -Lk = Tw - Wr -Lk = Wr - Tw -Lk = Tw + Wr
Lk = Tw + Wr
Which technique ionizes polypeptides by embedding the tryptic fragments into a light-absorbing matrix and exposing it to a laser? -ESI -MALDI -NMR -X-ray crystallography
MALDI
Trace directly the covalently bonded backbone atoms from the N to C terminus of a dipeptide. Which atoms are found in this trace? -NCCNCC -NCCONCCO -NCONCO -CNCCNC
NCCNCC
What are the three-letter and one-letter abbreviations for the amino acid tyrosine? -Tyo, T -Tyr, R -Tro, Y -Tyr, Y
Tyr, Y
Which form(s) of DNA exhibit(s) a zigzag arrangement? -A-DNA -B-DNA -Z-DNA -A-DNA and B-DNA
Z-DNA
Given a solution with pH > pKa, what are the relative concentrations of A- and HA? -[HA] > [A-] -[HA] < [A-] -[HA] = [A-] -[HA] = [A-] = 1
[HA] < [A-]
The _______ system controls the interconversion among ATP, ADP and AMP. -phosphorylate -adenylate -energy conversion -metabolism
adenylate
The basic structure of DNA is a right-handed helix formed by two _________ strands of DNA. -antiparallel -parallel -coding -template
antiparallel
If the Gibbs free energy change value for a reaction is less than zero, this reaction is -exergonic -endergonic -exothermic -endothermic
exergonic
The essential ions calcium, magnesium, potassium, and sodium are all: -anions -cations -transition metals -halogens
cations
During eukaryotic DNA condensation, nucleosomes are packed together to form -histones -chromatin -chromosomes -genes
chromatin
When DNA is transcribed into RNA, the ________ strand has the same base sequences as the RNA transcript. -antiparallel -parallel -coding -template
coding
Enzymes function as reaction catalysts in cells. If the enzymes were removed from a cell, the rate of biochemical reactions would: -increase -remain the same -decrease -it is impossible to know
decrease
The birth of modern biochemistry can be traced to: -end of 19th century -end of 20th century -beginning of 19th century -beginning of 21st century
end of 19th century
Which of the following is an example of an ecosystem? -mammals -plasma membrane -insects -forest
forest
When DNA is sequenced, which analytical technique is used to separate the chain-terminated DNA fragments? -gel electrophoresis -blue-white screening -antibiotic resistance -fluorescent labeling
gel electrophoresis
Which of the following is an example of a metabolic pathway? -mitochondria -organelles -glycolysis -plasma membrane
glycolysis
Chromatin that consists of more condensed regions of mostly noncoding DNA are referred to as -nucleosomes -histones -heterochromatin -euchromatin
heterochromatin
The K+ ion concentration in a DNA sample is increased from 50 mM to 100 mM. The Tm will -remain the same -decrease -increase -vary unpredictably
increase
In the eukaryotic cell, the NONcoding sequences on a gene are referred to as -exons -operons -introns -promoter
introns
Which amino acid has the highest pKa? -glutamate -asparagine -cysteine -lysine
lysine
Why are fewer polypeptide sequences encountered biologically than are theoretically possible? -there is no way to make all the theoretical possibilities -the phosphodiester linkages don't allow for all the possibilities -not all have useful structural and functional properties -not all of the possibilities can be broken down
not all have useful structural and functional properties
Several histones can bind to one DNA molecule, forming a repeating unit called a -ribozyme -nucleosome -topoisomerase -nucleoside
nucleosome
The protein fold known as the Rossman fold is found in proteins that commonly bind -alpha-helices -nucleotides -cytochromes -membranes
nucleotides
Type I topoisomerase activity results in a region of __________ DNA. -semiconservative -spliced -relaxed -unrepaired
relaxed
The ________ differentiates amino acids from one another. -number of silane groups -number of phosphoryl groups -side chains attached to the central carbon -number of hydroxyl groups
side chains attached to the central carbon
When DNA is transcribed into RNA, the _______ strand has the complementary sequence to the transcribed RNA. -antiparallel -parallel -coding -template
template
