Quiz
Biochemistry 192
Create a free account to finish this quiz
Save your progress and see your final score.
Already have an account? Sign in
Questions in this quiz (194)
1The central dogma of molecular biology describes how:
- AA. RNA molecules are reverse translated to DNA in human cells
- BB. the message contained in the DNA is transcribed to mRNA and translated to protein.
- CC. the message contained in a protein molecule signals a cellular response
- DD. the enzyme lactase breaks lactose into galactose and glucose.
2The function of a protein is determined by its:
- AA. three-dimensional shape.
- BB. absorbance properties.
- CC. specific cofactors found in the sidechain.
- DD. concentration in solution.
3The sequence of what in a protein determines how it folds?
- AA. Nucleic acids
- BB. Amino acids
- CC. Sugars
- DD. Phospholipids
4Why might a biochemist make a particular protein in the laboratory?
- AA. To determine its structure.
- BB. To determine its function.
- CC. To determine what it interacts with.
- DD. All the above.
5Proteins are polymers of:
- AA. nucleoside monophosphates linked together by covalent bonds.
- BB. amino acids linked together by ester covalent bonds.
- CC. amino acids linked together by non-covalent omega bonds.
- DD. amino acids linked together by peptide covalent bonds.
6What level(s) of protein structure(s) are stabilized with PRIMARILY hydrogen bonds?
- AA. Primary
- BB. Secondary
- CC. Tertiary
- DD. Quaternary
7Which statement regarding hydrogen bonds is INCORRECT?
- AA. Hydrogen bonding is important for stabilizing secondary structure in
proteins. - BB. Hydrogen bonds in alpha helices form between the carbonyl oxygen from a peptide bond and the amino hydrogen from a different peptide
bond further along the polypeptide chain. - CC. Hydrogen bonds between amino acid sidechains can stabilise the tertiary structure of proteins.
- DD. Hydrogen bonds stabilize the primary sequence of amino acids.
- AA. Hydrogen bonding is important for stabilizing secondary structure in
8Which statement about protein secondary structure is CORRECT?
- AA. Beta sheets are pleated structures with a slight left-handed twist.
- BB. Alpha helices cannot have a polar and a non-polar side.
- CC. Turns, loops and coils connect beta strands and alpha helices together.
- DD. Parallel beta strands are connected by supersecondary structures.
9In proteins, supersecondary structures are:
- AA. extra-large alpha-helices and beta-sheets.
- BB. structural features that have more than one secondary structural
element. - CC. always joined together by disulfide bonds between residues from
different secondary structure elements. - DD. β-turns between alpha-helices.
10Which forms of the alpha-amino and alpha-carboxyl groups of alanine
are most likely to occur at very high pH (for the free amino acid)?- AA. NH3+ and COO-
- BB. NH2 and COO-
- CC. NH2 and COOH
- DD. NH3+ and COOH
11Amino acid side chain modification such as:
- AA. phosphorylation is commonly used to control enzyme activity, like an ON/OFF switch.
- BB. hydroxylation facilitates hydrogen bond formation required for the activation of blood clotting factors.
- CC. carboxylation, when applied to haemoglobin, can be used to diagnose, and monitor diabetes.
- DD. glycosylation catalyses disulfide bond formation to stabilise tertiary protein structures.
12An alpha helix in a protein contains:
- AC. 3.6 amino acids per turn, does not normally contain proline and is often polar on one side and non-polar on the other side.
- BD. 4.5 amino acids per turn and is stabilised by hydrogen bonds between every fourth amino acid.
- CB. 3.6 amino acids per turn, has the amino acid side chains facing the inside of the helix and can vary in length.
- DA. 3.6 amino acids per turn and is stabilised by covalent crosslinks.
13Which statement about beta turns is INCORRECT?
- AA. They are relatively short, normally four residues in length.
- BB. They connect individual polypeptides.
- CC. They commonly contain proline residues.
- DD. They commonly contain glycine residues.
14EDHWVNQYSAIT is an amino acid sequence that can form an alpha helix.
Which residues are involved in forming a hydrogen bond with residue Q
(underlined)?- AA. H and I
- BB. W and A
- CC. V and S
- DD. H and T
15The four main classifications of amino acids, based on the properties of their side chains, are:
- AA. non-polar, polar uncharged, polar positively charged, polar negatively charged.
- BB. non-polar charged, non-polar uncharged, polar uncharged, polar
charged. - CC. lipophilic, hydrophobic, hydrophilic, hydrobonded.
- DD. ionic, hydrogen, van der Waals, electrostatic.
16The peptide bond in proteins is:
- AA. planar.
- BB. highly flexible.
- CC. never in the trans conformation.
- DD. an ionic bond.
17Which one of the following statements about protein structure is
INCORRECT?- AA. Beta-sheets are stabilised by hydrogen bonds between carbonyl oxygens and amino hydrogens from amino acids that are next to each other on the same beta-strand.
- BB. Domains are discrete parts of a protein structure, usually associated
with a particular function. - CC. The primary sequence of a polypeptide determines how the protein will
fold. - DD. Proteins made from three polypeptide chains show quaternary structure.
18What is the main driving force in protein folding?
- AA. Covalent bond formation.
- BB. Hydrogen bond formation.
- CC. Hydrophobic core formation.
- DD. Disulfide bond formation.
19An enzyme catalysed reaction:
- AA. releases more energy than the equivalent uncatalyzed reaction.
- BB. has a lower activation energy than the equivalent uncatalyzed reaction.
- CC. can only proceed in one direction.
- DD. increases the rate of reaction by bringing the energy of the products closer to the energy of reactants (substrates).
20Which statement about the role of enzymes in cellular metabolism is
INCORRECT?- AA. Enzymes speed up reaction rates.
- BB. Enzymes ensure that all chemical reactions are at equilibrium.
- CC. Enzymes can be regulated by metabolic products.
- DD. Enzymes can couple reactions to make the overall ΔG negative.
21Pyridoxal phosphate (PLP) is present in the active site of glycogen
phosphorylase, where it acts as a(n):- AA. Non-competitive inhibitor.
- BB. Transition state intermediate.
- CC. Coenzyme.
- DD. Allosteric activator.
22What enables enzymes to bind to substrates very selectively?
- AA. The 3D geometry and chemical properties of the active site
- BB. Post-translational modifications of the active site.
- CC. Enzyme cofactors.
- DD. Physiological substrate concentrations.
23Which effect below does NOT contribute to enzymatic catalysis?
- AA. Correct orientation and proximity of substrates.
- BB. Irreversible binding of substrates to the active site.
- CC. Proton transfer between acidic and basic side chains.
- DD. Metal ions acting as cofactors.
24Enzymes usually bind BEST to:
- AA. the substrates of the enzyme.
- BB. the products of the reaction catalysed.
- CC. the transition state of the reaction catalysed.
- DD. allosteric regulators of the enzyme.
25The active site of an enzyme:
- AA. enables destabilization of the transition state.
- BB. is a discrete three-dimensional pocket on the enzyme that is separate from the substrate binding site.
- CC. includes amino acid sidechains that specifically bind substrate through multiple weak interactions.
- DD. always forms a covalent bond with the substrate to ensure that the chemical reaction is completed.
26Vmax is the maximum rate of reaction an enzyme can catalyse when:
- AA. saturated with substrate.
- BB. substrate concentration is at half KM.
- CC. substrate concentration is at KM.
- DD. substrate concentration is limited.
27In enzyme kinetics, a progress curve:
- AB. shows the appearance of product or disappearance of substrate, over time.
- BD. has a constant slope (gradient) across time because the rate of enzyme catalysis is constant.
- CC. becomes less steep (decreases in gradient) as the rate of reaction
increases. - DA. becomes less steep with time because enzyme concentration increases.
28Which one of the following statements about enzyme kinetics is
INCORRECT?- AA. At substrate concentrations below KM the velocity of a reaction varies
with substrate concentration. - BC. When comparing kcat/KM values for different enzymes, enzymes with
higher values are more efficient. - CD. The velocity of a reaction at any particular substrate concentration [S]
depends on the Vmax and KM of the enzyme. - DB. The Vmax of a reaction will not change if more enzyme is added.
- AA. At substrate concentrations below KM the velocity of a reaction varies
29The inhibitor used in the experiment above is a:
- AA. competitive inhibitor because it decreases Vmax.
- BB. competitive inhibitor because it increases KM.
- CC. non-competitive inhibitor, because it increases KM.
- DD. non-competitive inhibitor, because Vmax remains the same.
30An enzyme-catalysed reaction in the presence of a competitive inhibitor:
- AC. has an unaltered KM, as the shape of the enzyme is unchanged by the
inhibitor. - BD. can achieve the same Vmax as the uninhibited enzyme if given enough substrate.
- CB. has the same velocity as the uninhibited reaction at low substrate
concentrations. - DA. has the same reaction rate at all concentrations of inhibitor.
- AC. has an unaltered KM, as the shape of the enzyme is unchanged by the
31In the presence of a non-competitive inhibitor, Vmax will:
- AA. remain unchanged while KM increases.
- BB. remain unchanged while KM decreases.
- CC. increase, while KM will remain unchanged.
- DD. decrease, while KM will remain unchanged.
32Which statement about the glycogen phosphorylase enzyme is
INCORRECT:- AA. Glycogen phosphorylase can be regulated by post-translational
modification. - BB. Glycogen phosphorylase is activated by directly binding to insulin.
- CC. Allosteric regulators can increase or decrease glycogen phosphorylase
activity. - DD. Glycogen phosphorylase releases glucose-1-phosphate in response to
energy demand.
- AA. Glycogen phosphorylase can be regulated by post-translational
33Myoglobin:
- AA. can bind one oxygen molecule.
- BB. acts as an oxygen transporter in blood.
- CC. binds 2,3-bisphosphoglycerate (BPG) with high affinity.
- DD. displays a linear oxygen binding curve as it binds oxygen very tightly.
34Proteins that show cooperativity:
- AA. Are monomeric.
- BB. Have a hyperbolic graph of binding versus substrate concentration ([S]).
- CC. Favour the R-state at high [S] (substrate concentration)
- DD. Are not subject to allosteric control
35The T-state of haemoglobin is stabilised by:
- AA. Binding of bisphosphoglycerate (BPG) between subunits.
- BB. Binding of oxygen to the Fe2+ ion in the haem.
- CC. Protonation of globin residue side chains.
- DD. CO2 binding to the Fe2+ ion in the haem.
36Haemoglobin displays a sigmoidal oxygen binding curve because the
binding of oxygen:- AA. to each haemoglobin subunit is independent.
- BB. causes the haem groups to interact directly.
- CC. to one subunit can change the conformation of the other subunits.
- DD. causes the haemoglobin subunits to covalently bond.
372,3-bisphosphoglycerate (BPG):
- AA. increases the oxygen carrying capacity of haemoglobin
- BB. binds with a higher affinity to foetal haemoglobin than to adult
Haemoglobin - CC. binds to the haem Fe2+ to facilitate oxygen release.
- DD. binds allosterically to stabilise the T-state of haemoglobin.
38What connects allosteric control and cooperativity?
- AA. Both give rise to a sigmoidal activity curve.
- BB. Both are features of myoglobin.
- CC. Both occur only in multimeric proteins.
- DD. Both can modify substrate-target binding affinity.
39Which of the following is a chemical substance that activates a
receptor?- AA. Agonist.
- BB. Antagonist.
- CC. Substrate.
- DD. Inhibitor.
40Which of the following is a chemical substance that prevents the
activation of a receptor by an agonist?- AB. Allosteric modulator
- BD. Competitive inactivator
- CC. Substrate
- DA. Antagonist
41Fill in the blank with the best option: Antagonist is to receptor as
_______ is to enzyme.- AA. Inhibitor.
- BB. Activator.
- CC. Substrate.
- DD. Ligand.
42Select the INCORRECT pair relating to the specificity of ligands and
receptors:- AD. Adrenaline and muscarinic acetylcholine receptor.
- BC. Amylin and amylin receptor.
- CB. Insulin and insulin receptor.
- DA. 5-HT and 5-HT1b receptor.
43A patient has hypoglycaemia and is going to be treated using the
GlucaGen HypoKit. This contains a synthetic version of the hormone
glucagon, which acts in the same way as naturally occurring glucagon.
Which of the following statements relating to glucagon is correct?- AA. Glucagon uses a G protein-coupled receptor to produce signal
transduction. - BB. Glucagon is an antagonist of the insulin receptor.
- CC. Glucagon is a steroid hormone.
- DD. Synthetic glucagon in an analogue of GLP-1.
- AA. Glucagon uses a G protein-coupled receptor to produce signal
44Which of the following is NOT a second messenger that is used by G
protein-coupled receptors?- AA. cAMP
- BB. cGMP
- CC. Diacylglycerol
- DD. Adenylate cyclase
45Which statement regarding receptor proteins is INCORRECT?
- AA. Receptors have several binding sites.
- BB. Receptors bind ligands.
- CC. Receptors release the ligand as a changed product.
- DD. Receptors can be membrane bound or free in the cytosol.
46A pharmaceutical company wants to identify a novel antagonist for a G
protein-coupled receptor. Which of the following would be a good
chemical starting point for their drug discovery programme?- AA. The endogenous ligand for their target receptor.
- BB. Adenosine triphosphate (ATP).
- CC. Steroid receptor acting drugs.
- DD. A chemical compound library of ion channel antagonist molecules.
47The flow of genetic information in a cell is:
- AA. Protein -> mRNA -> DNA.
- BB. DNA -> mRNA -> Protein.
- CC. DNA -> Protein -> mRNA.
- DD. mRNA -> DNA -> Protein.
48Translation is the synthesis of:
- AD. mRNA from a DNA template.
- BC. Protein from an mRNA template.
- CB. DNA from an mRNA template.
- DA. Protein from a DNA template.
49Which one of the following are the key elements of a gene?
- AA. Promotor region, exons, transcription factor binding sites, introns.
- BB. Promoter region, plasmid, post-translational modification, exons.
- CC. Exons, initiator tRNA, RNA polymerase, start codon.
- DD. Exons, small ribosomal subunit, start codon, plasmid.
50Alternate forms of a gene are called:
- AA. Genotypes.
- BD. Codons.
- CB. Polymorphisms.
- DC. Alleles.
51Which statement about the inheritance of alleles in humans is true?
- AB. Both alleles come from the mother.
- BD. Both alleles come from either parent.
- CC. One allele comes from each parent.
- DA. Both alleles come from the father.
52If two straight-haired people have a curly-haired child, the parents’
genotypes for hair type must be:- AA. homozygous for straight hair
- BB. heterozygous.
- CC. homozygous for curly hair.
- DD. unknown, not enough information was given.
53Which of the following genetic variants is LEAST LIKELY to have severe
consequences on protein function?- AB. A variant that changes a codon to another codon for the same amino acid.
- BD. A variant that deletes an entire codon.
- CC. A variant that changes a codon to another codon for a different amino acid.
- DA. A variant that introduces a premature stop codon.
54A persons’ genotype can be determined by:
- AA. A PCR-RFLP assay.
- BB. A sequencing assay.
- CD. All of the above.
- DC. A TaqMan genotyping assay.
55Why is PCR (polymerase chain reaction) commonly used in genetic
testing?- AA. It extracts all the DNA from a cell.
- BB. It generates a large number of copies of a specific DNA region.
- CC. It cuts a gene at a unique restriction site.
- DD. It separates DNA fragments based on size
56Sickle Cell Anaemia is:
- AA. a polygenic disease caused by genetic variants in multiple genes involved
in oxygen transport. - BB. a disease caused by an increase in haemoglobin in the blood as a sideeffect of certain medications.
- CC. a monogenic disease caused by the E6V haemoglobin genetic variant.
- DD. none of the above.
- AA. a polygenic disease caused by genetic variants in multiple genes involved
57A disease or disorder can be:
- AA. 100% caused by genetics.
- BB. 50:50 caused by genetics and environment.
- CC. 100% caused by the environment.
- DD. All of the above.
58A genetic variant could cause a severe phenotype if it modifies the
function of a protein:- AA. only at the beginning of a metabolic pathway.
- BB. only at the end of a metabolic pathway.
- CC. only in the middle of a metabolic pathway.
- DD. anywhere in a reaction pathway.
59The effect of a genetic variant on a person’s phenotype can be modified
by the environment if:- AD. The person’s phenotype was solely determined by environment.
- BC. The affected gene normally interacts with the environment.
- CB. The affected gene produces a non-functional protein.
- DA. The genetic variant does not severely change the protein’s function.
60What is the BEST explanation of why an older person has a higher
chance of getting cancer?- AA. Because their DNA has been replicated more times.
- BB. Because their DNA has been damaged over time.
- CC. Because their DNA has been transcribed more times.
- DD. Because their DNA has become unstable over time.
61A complex disease is a disease that:
- AA. is complicated to treat.
- BB. is caused by a protein complex.
- CC. is caused by multiple, complicated gene-environment interactions.
- DD. has a complex diagnostic test.
62You have engineered a new protein and named it “PepZ”. To function, it
must be gamma-carboxylated. Which host would be BEST to produce
functional “PepZ” recombinantly?- AC. Oilseed crops.
- BD. Goats
- CB. Chinese Hamster Ovary Cells.
- DA. Bacteria.
63Which ONE of the following is NOT an advantage of using eukaryotic
cells to produce therapeutic proteins, compared to sourcing proteins
from human tissues?- AB. Reduces the risk of contamination and transmission of infectious agents.
- BD. Can make proteins from any tissue.
- CC. Ensures a correct gamma-carboxylation pattern.
- DA. Can make large amounts of protein.
64Which statement about recombinant expression vectors is INCORRECT?
- AD. They can be used to produce recombinant proteins.
- BC. They are double-stranded pieces of linear DNA.
- CB. They contain a promoter.
- DA. They are circular pieces of double-stranded DNA.
65Which of these protein types and recombinant production systems do
NOT go together when producing recombinant protein?- AD. None of the above.
- BC. Protein without post-translational modifications and mammalian cells.
- CB. Glycosylated protein and bacteria.
- DA. Glycosylated protein and CHO cells.
66Restriction enzymes cut:
- AD. proteins at random sites.
- BC. DNA at specific sites
- CB. DNA at random sites.
. - DA. proteins at specific sites.
67Which statement is CORRECT?
- AB. Human insulin cannot be produced using bacterial host cells because
bacteria cannot complete the required glycosylation. - BC. It is not possible to produce human insulin using bacterial cells because
eukaryotic proteins like human insulin must always be produced using a
eukaryotic host cell. - CA. Functional human insulin is a large protein that is made up of three
polypeptide chains held together by disulfide bonds. - DD. The A and B chains of human insulin can be synthesized recombinantly
without the requirement for in vivo (in the cell) post-translational
modifications.
- AB. Human insulin cannot be produced using bacterial host cells because
68Recombinant insulin is produced in:
- AD. transgenic cows
- BB. mammalian cell culture
- CA. E.coli
- DC. oilseed crops
69Erythropoietin:
- AC. can be used to treat anaemic cancer patients.
. - BD. requires a mammalian restriction enzyme when expressed from a
bacterial plasmid - CB. is not glycosylated when produced in Chinese Hamster Ovary (CHO) cells.
- DA. can be successfully produced in bacteria.
- AC. can be used to treat anaemic cancer patients.
70Genes containing introns cannot be expressed in bacteria because:
- AC. bacterial expression vectors are too small for genes containing introns.
- BD. bacteria do not have the cellular machinery required for splicing out
introns. - CB. bacterial expression vectors cannot replicate introns in genes.
- DA. bacteria do not have the cellular machinery required for transcription.
71EPO and insulin can both be produced in E. coli. Which of these
statements about EPO and/or insulin production is CORRECT?- AC. Insulin produced in E. coli is not functional because it requires
glycosylation. - BB. Both EPO and insulin produced in E. coli are functional.
- CA. EPO produced in E. coli is not functional because it requires glycosylation.
- DD. Neither EPO nor insulin produced in E.coli are functional.
- AC. Insulin produced in E. coli is not functional because it requires
72When whole animals are used to make therapeutic recombinant
proteins, restricting expression to specific tissues can BEST be
controlled by using:- AC. antagonists to specifically block expression receptors in non-desirable
tissues. - BD. an origin of replication within the plasmid.
- CB. a mammalian cell-type specific promoter.
- DA. a bacterial promoter.
- AC. antagonists to specifically block expression receptors in non-desirable
73The major benefit of gene therapy compared to conventional
biotechnology is:- AD. it has no side effects.
- BC. it is less expensive than conventional treatments.
- CB. it can treat genetic disorders at their source.
- DA. it requires no regulatory approval.
74Twelve mL of solution A is mixed with 24 mL of solution B. Following the
dilution, solution A has a concentration of 30 mg/L. Which statement
about this dilution is CORRECT?- AD. There has been a four-fold dilution of solution B.
- BC. The undiluted solution A had a concentration of 90 mg/mL.
- CB. The undiluted solution B had a concentration of 10 mg/mL.
- DA. The concentration of solution A will decrease 1.5-fold.
75A 1 in 12 dilution of an enzyme means:
- AA. 1 part enzyme diluted with 11 parts of buffer.
- BB. 1 part enzyme diluted with 12 parts of buffer.
- CC. 1 part buffer diluted with 11 parts of enzyme.
- DD. Total parts of enzyme and buffer are 13.
76In order to dilute a solution from 90 mg.mL-1
to 15 mg.mL-1 you would need to add:- AD. 1 part water to 100 parts solution.
- BA. 1 part solution to 5 parts water.
- CB. 1 part solution to 6 parts water.
- DC. 1 part water to 89 parts solution.
77Which structural component of starch is responsible for the formation of
a dark blue-black colour in the "iodine starch test"?- AC. Cellulose
- BB. Amylopectin
- CA. Amylose
- DD. Glucose
78Hight heat (80C) affects bonds stabilising protein:
- AD. tertiary and quaternary structure.
- BC. secondary and tertiary structure.
- CB. secondary, tertiary, and quaternary structure.
- DA. primary, secondary, and tertiary structure
79In spectrophotometry Beer’s Law indicates that the absorbance of light
by an absorbing solution at a particular wavelength is directly proportional to the:- AD. Pathlength through the solution.
- BC. Concentration of the solution.
- CB. Molar absorbance coefficient.
- DA. Wavelength of light used.
80In spectrophotometry, Lambert’s Law indicates that for monochromatic
light passing through an absorbing solution, the intensity of transmitted
light:- AD. decreases exponentially with increasing pathlength.
- BC. decreases logarithmically with increasing pathlength.
- CB. increases logarithmically with increasing pathlength.
- DA. increases exponentially with increasing pathlength.
81In the Beer-Lambert Law (A = ε.c.l), the term “l” denotes the:
- AA. molar absorbance coefficient.
- BB. wavelength of light used.
- CC. light-path length.
- DD. absorbance of light used.
82The wavelength at which a molecule absorbs light maximally:
- AB. is dependent on the concentration of the molecule.
- BC. can be determined using the molar absorbance coefficient.
- CA. is dependent on the distance light of a given wavelength travels through the solution.
- DD. can be determined by constructing an absorbance spectrum.
83Which statement about spectrophotometry is INCORRECT?
- AA. A red solution is likely to have low absorbance at wavelengths in the red region of the visible spectrum.
- BB. The molar absorbance coefficient for a solute does not change when substrate concentration changes.
- CC. The wavelength of a standard cuvette is 1 cm.
- DD. The amount of light absorbed by a solution is dependent on solute concentration.
84Which statement is CORRECT?
- AC. A graph of absorbance versus wavelength is referred to as a standard curve.
- BD. Pathlength describes the linear relationship between the concentration and the absorbance of a molecule in solution.
- CB. The molar absorbance coefficient is dependent on the concentration of the absorbing solution.
- DA. When using enzyme assays to analyse complex solutions for specific molecules, it is assumed that the reaction goes to completion.
8580 mL of solution A was added to a test tube with 720 mL of water.
Which of the following describes the dilution of solution A?- AA. 1 in 9 dilution.
- BB. 1 in 10 dilution.
- CC. 1 in 12 dilution.
- DD. 1 in 15 dilution.
86Which of the following best describes the DECREASE in the gradient of a
progress curve with time?- AD. The increasing concentration of product signals to the enzyme to slow down.
- BC. The enzyme is saturated with substrate so the reaction can’t go any faster.
- CB. Substrate concentration decreases over the reaction period.
- DA. All the enzyme is used up by the reaction.
87A good standard curve where absorbance is plotted against the
concentration of a molecule:
I. passes through the origin.
II. has a hyperbolic shape.
III. is a straight line.
IV. has a line that can go past the last measured point.
V. has absorbance values plotted on the x-axis.- AA. II, IV and V
- BB. I and III
- CC. I, III and V
- DD. II and IV
88Alcohol dehydrogenase catalyses the conversion of:
- AD. acetaldehyde to acetate.
- BC. ethanol to methanol.
- CA. ethanol to acetaldehyde.
- DB. ethanol to ethanoic acid.
89A spectrophotometry experiment on solution Y found the absorbance at
500 nm to be 0.268. The pathlength is 1 cm and the molar absorbance
coefficient of the molecule in solution Y is 23,500 L.mol-1
.cm-1
.
What is the concentration of the diluted solution?- AA. 68.4 mol.L-1
- BB. 6.84 mmol.L-1
- CC. 11.4 mol.L-1
- DD. 114 mmol.L-1
90A 40 mM solution of ethanol is diluted 1 in 4. The diluted ethanol
solution was used for an alcohol dehydrogenase (ADH) assay that had a
total volume of 4 mL. 800 μL of ADH was used for the assay. The
reaction was followed spectrophotometrically, and a progress curve
plotted from the spectrophotometric data. Using the progress curve, the
initial velocity was calculated as 0.3 ΔA/s.
The assay was repeated as above, except that 200 μL of ADH was
used. What would the initial velocity be in this assay?- AA. 0.075 ΔA/s
- BB. 9.6 ΔA/s
- CC. 4.5 ΔA/min
- DD. 5.5 ΔA/min
91Which of the following statements accurately describes the composition of proteins?
- AB) Proteins are non-branching polymers made of amino acids linked by peptide bonds.
- BD) Proteins are composed of polysaccharides linked by glycosidic bonds.
- CC) Proteins are made of nucleotides linked by phosphodiester bonds.
- DA) Proteins are branching polymers made of fatty acids linked by ester bonds.
92Why is it important to study the 3D structure of proteins?
- AA) The 3D structure helps determine how proteins replicate.
- BB) The 3D structure reveals how proteins can form peptide bonds.
- CC) The 3D structure is crucial for understanding protein function.
- DD) The 3D structure shows the number of amino acids in a protein.
93Which of the following techniques is commonly used to determine protein structure?
- AD) Western blotting
- BC) Gel electrophoresis
- CB) X-ray crystallography
- DA) PCR (Polymerase Chain Reaction)
94Which protein is involved in oxygen transport in the blood?
- AD) Hexokinase
- BC) Hemoglobin
- CB) Amylase
- DA) Trypsin
95Proteins play a role in all of the following cellular processes except:
- AD) DNA storage
- BC) Oxygen transport
- CB) Metabolism
- DA) Immune defense
96Which of the following is an example of a protein involved in metabolism?
- AD) Amylase
- BC) Hemoglobin
- CB) Hexokinase
- DA) Insulin
97What is the primary reason for proteins adopting a complex 3D structure?
- AD) To increase their length
- BC) To facilitate specific molecular interactions
- CB) To enhance peptide bond formation
- DA) To store genetic information
98Which protein is essential for glucose metabolism by phosphorylating glucose?
- AD) Insulin
- BC) Hexokinase
- CB) Trypsin
- DA) Alcohol dehydrogenase
99Which of the following proteins is involved in viral replication?
- AD) Amylase
- BC) Hemoglobin
- CB) SARS-CoV2 spike protein
- DA) Alcohol dehydrogenase
100What is the key characteristic that makes proteins "workhorses of the cell"?
- AD) They store genetic information.
- BC) They provide structural integrity to DNA.
- CB) They facilitate nearly all biochemical processes.
- DA) They store energy.
101Which of the following statements is true about amino acids?
- AA. All amino acids are chiral.
- BB. Glycine is an exception to the rule of chirality in amino acids.
- CC. Amino acids cannot exist as zwitterions.
- DD. Amino acids do not have varied chemical properties based on their side chains.
102How are amino acids classified based on their side chains?
- AD. Linear, branched, cyclic, or aromatic
- BC. Essential, non-essential, conditional, or non-standard
- CB. Hydrophobic, hydrophilic, neutral, or charged
- DA. Non-polar, polar (uncharged), positively charged (basic), or negatively charged (acidic)
103What does the one-letter abbreviation "E" represent in amino acid nomenclature?
- AD. Serine
- BC. Glycine
- CB. Glutamate
- DA. Glutamine
104Which term describes the pH at which the net charge of an amino acid is zero?
- AD. pH₀
- BC. pH
- CB. pI (isoelectric point)
- DA. pKa
105What is the role of post-translational modifications in proteins?
- AC. They regulate enzyme activity, modify protein function, and can prevent diseases.
- BD. They determine the primary sequence of amino acids in proteins.
- CB. They alter the amino acid sequence before protein folding.
- DA. They are involved in the initial synthesis of amino acids.
106Which of the following statements is true about peptide bonds?
- AD. Peptide bonds are easily hydrolyzed under normal physiological conditions.
- BC. Peptide bonds have a partial double-bond character, making them planar and stable.
- CB. Peptide bonds have a single bond character and no dipole.
- DA. Peptide bonds are flexible and non-planar.
107Which factor primarily determines a protein's structure and function?
- AD. The rate of post-translational modifications
- BC. The presence of ionisable groups
- CB. The sequence of amino acids and the chemical properties of their side chains
- DA. The pH of the surrounding environment
108Which level of protein structure is defined by the sequence of amino acids in a polypeptide chain?
- AD. Quaternary Structure
- BC. Primary Structure
- CB. Tertiary Structure
- DA. Secondary Structure
109What type of bonding stabilizes the secondary structures such as α-helices and β-sheets in proteins?
- AC. Hydrogen Bonds
- BD. Van der Waals Forces
- CB. Covalent Bonds
- DA. Ionic Bonds
110The overall 3D arrangement of a single protein chain, including all secondary structural elements, is referred to as which level of protein structure?
- AD. Quaternary Structure
- BC. Tertiary Structure
- CB. Secondary Structure
- DA. Primary Structure
111Which level of protein structure involves the interaction and arrangement of multiple polypeptide chains or subunits?
- AD. Quaternary Structure
- BC. Tertiary Structure
- CB. Secondary Structure
- DA. Primary Structure
112What is the characteristic feature of peptide bonds in terms of their structure and configuration?
- AD. They are flexible and can easily rotate around the N–Cα bond.
- BC. They are single bonds with no partial double-bond character and can adopt both cis and trans configurations equally.
- CB. They exhibit partial double-bond character, are planar and rigid, and typically adopt a trans configuration.
- DA. They are flexible and non-planar, typically adopting a cis configuration.
113Which backbone bond angles are key to determining the protein’s main chain conformation?
- AD. Theta (θ), Lambda (λ), and Zeta (ζ)
- BC. Delta (δ), Sigma (σ), and Kappa (κ)
- CB. Phi (ϕ), Psi (ψ), and Omega (ω)
- DA. Alpha (α), Beta (β), and Gamma (γ)
114Which secondary structural element in proteins is characterized by a right-handed spiral with approximately 3.6 amino acids per turn?
- AD. Coil
- BA. β-Sheet
- CB. Turn
- DC. α-Helix
115What structural feature allows a protein chain to reverse direction in a short sequence of amino acids?
- AD. Coil
- BC. Turn
- CB. α-Helix
- DA. β-Sheet
116Which visualization technique is commonly used to highlight the helices, strands, turns, and coils in protein structures?
- AD. Ball-and-Stick Models
- BB. Schematic Diagrams
- CC. Ribbon Diagrams (Richardson Diagrams)
- DA. Space-Filling Models
117What components are involved in building the tertiary structure of a protein?
- AD. Tertiary structure, Quaternary structure, Protein folding
- BC. Primary structure, Supersecondary structure, Protein domains
- CB. Secondary structure, Supersecondary structure, Protein domains, Complete protein structures
- DA. Primary structure, Secondary structure, Tertiary structure
118Which of the following is an example of a supersecondary structure?
- AD. Protein domain
- BC. Helix-turn-helix
- CB. β-Sheet
- DA. α-Helix
119What characterizes a protein domain?
- AD. A type of supersecondary structure that does not interact with other domains
- BC. A structural element that only appears in the quaternary structure
- CB. Independently folded regions within proteins with specific functions, often characterized by a hydrophobic core
- DA. A sequence of amino acids with no specific folding pattern
120How are protein families typically grouped?
- AD. By post-translational modifications
- BC. Based on tertiary structure
- CB. By sequence similarity
- DA. Based on amino acid composition
121Which protein family is characterized by mostly helical structures?
- AD. β-barrel family
- BC. α-domain family
- CB. Antiparallel β family
- DA. α/β family
122Why is life not considered to be at equilibrium?
- AD. Life's metabolic processes are completely random and uncontrolled
- BC. Life requires a network of biochemical reactions that are not at equilibrium, allowing for useful work to be done
- CB. Life's reactions occur in a fixed, unchanging state
- DA. Life sustains itself through a network of reactions that are at equilibrium
123How do enzymes contribute to fitting reactions within the timescale necessary for life processes?
- AD. By making reactions less specific to their substrates
- BC. By accelerating reactions, thereby allowing them to proceed at a faster rate
- CB. By decelerating reactions to prolong their duration
- DA. By increasing the equilibrium constant of the reactions
124Which of the following is a function of cofactors in enzyme catalysis?
- AD. They act as inhibitors of enzyme activity
- BC. They assist in enzyme catalysis by stabilizing reaction intermediates or participating directly in the reaction
- CB. They provide structural support to the enzyme
- DA. They are part of the enzyme's amino acid sequence
125What role do metal ions play in enzyme catalysis?
- AD. They act as competitive inhibitors of enzyme activity
- BC. They degrade the enzyme to recycle its components
- CB. They stabilize reaction intermediates and can be crucial for catalytic activity
- DA. They bind to the enzyme's active site and prevent substrate binding
126Which of the following best describes coenzymes?
- AD. Large protein molecules that change the enzyme's structure
- BC. Metal ions that assist in stabilizing reaction intermediates
- CB. Organic molecules that bind to the enzyme and participate in the chemical reaction
- DA. Non-protein molecules that are permanently attached to the enzyme
127What is the optimal binding of an enzyme to its substrate?
- AD. The enzyme binds to the substrate with a fixed, non-flexible bond.
- BC. The enzyme binds to the substrate weakly to ensure minimal interaction.
- CB. The enzyme binds to the substrate just tight enough to facilitate catalysis but not too tight.
- DA. The enzyme binds to the substrate very tightly, which prevents any flexibility.
128Why are weak bonds advantageous in enzyme-substrate interactions?
- AD. They increase the activation energy required for the reaction.
- BC. They prevent the enzyme from undergoing any conformational changes.
- CB. They ensure that the enzyme-substrate complex is rigid and stable.
- DA. They allow for flexibility and specificity in the enzyme-substrate interaction.
129Which types of bonds are commonly formed between enzymes and substrates?
- AD. Van der Waals forces and covalent bonds
- BC. Disulfide bonds and ionic interactions
- CB. Ionic interactions, Van der Waals forces, and hydrogen bonds
- DA. Covalent bonds and hydrogen bonds
130What does the Lock and Key Model suggest about enzyme-substrate binding?
- AD. The enzyme and substrate interact through only weak bonds.
- BC. The substrate changes shape to fit into the enzyme’s active site.
- CB. The enzyme’s active site is complementary in shape to the substrate.
- DA. The enzyme undergoes conformational changes to accommodate the substrate.
131How does the Induced Fit Model differ from the Lock and Key Model?
- AD. The Induced Fit Model assumes that the enzyme's active site is pre-formed to match the substrate exactly.
- BC. The Induced Fit Model involves the enzyme undergoing conformational changes to fit the substrate more snugly.
- CB. The Lock and Key Model requires a perfect fit of the substrate into the enzyme’s active site.
- DA. The Induced Fit Model does not involve enzyme conformational changes.
132How is enzyme activity commonly monitored during an enzyme-catalyzed reaction?
- AA. By measuring the temperature of the reaction
- BB. By tracking changes in pH over time
- CC. By monitoring reaction rates over time
- DD. By analyzing the enzyme’s structure with X-ray crystallography
133What is the relationship between enzyme concentration and reaction rate?
- AD. Reaction rate increases exponentially with enzyme concentration
- BC. Reaction rate increases with enzyme concentration, up to a certain point
- CB. Reaction rate is unaffected by enzyme concentration
- DA. Reaction rate decreases as enzyme concentration increases
134How does substrate concentration affect the rate of an enzymatic reaction?
- AD. Reaction rate is independent of substrate concentration
- BC. Reaction rate increases with substrate concentration but eventually levels off at high concentrations
- CB. Reaction rate decreases as substrate concentration increases
- DA. Reaction rate increases linearly with substrate concentration
135What does the Michaelis-Menten equation describe?
- AD. The impact of pH on enzyme structure
- BC. The effect of temperature on enzyme activity
- CB. The rate of enzymatic reactions, assuming the formation of an enzyme-substrate complex
- DA. The relationship between enzyme concentration and substrate concentration
136What does KM represent in the Michaelis-Menten equation?
- AD. The time taken for the enzyme to convert substrate to product
- BC. The enzyme concentration required for maximum reaction rate
- CB. The substrate concentration at which the reaction rate is half of Vmax
- DA. The maximum reaction rate achieved by the enzyme
137What does kcat measure in enzyme kinetics?
- AD. The enzyme's affinity for the substrate
- BC. The substrate concentration at which the reaction rate is half of Vmax
- CB. The number of substrate molecules converted to product per enzyme molecule per second
- DA. The maximum reaction rate achieved by the enzyme
138What is the role of KM in enzyme kinetics?
- AD. It describes the total amount of enzyme present.
- BC. It represents the enzyme's turnover number.
- CB. It indicates the enzyme's affinity for the substrate; lower KM means higher affinity.
- DA. It measures the maximum rate of reaction.
139How do irreversible inhibitors affect enzyme activity?
- AD. They have no effect on enzyme activity.
- BC. They bind only to the enzyme-substrate complex.
- CB. They bind permanently, rendering the enzyme inactive.
- DA. They bind temporarily and can be removed.
140What distinguishes reversible inhibitors from irreversible inhibitors?
- AD. Reversible inhibitors bind only to the enzyme-substrate complex, while irreversible inhibitors bind to the active site.
- BC. Reversible inhibitors have no effect on enzyme activity, while irreversible inhibitors decrease activity.
- CB. Reversible inhibitors bind temporarily, while irreversible inhibitors bind permanently.
- DA. Reversible inhibitors bind permanently, while irreversible inhibitors bind temporarily.
141Which of the following describes competitive inhibition?
- AD. The inhibitor binds to both the enzyme and enzyme-substrate complex with different affinities.
- BC. The inhibitor competes with the substrate for binding at the active site, increasing KM but leaving Vmax unchanged.
- CB. The inhibitor binds permanently to the enzyme, rendering it inactive.
- DA. The inhibitor binds at a site other than the active site and decreases Vmax.
142What is the primary function of myoglobin in animals?
- AD. To bind carbon dioxide in the blood
- BC. To regulate enzyme activity
- CB. To store oxygen in muscles until required
- DA. To transport oxygen from the lungs to tissues
143What is the main structural difference between myoglobin and hemoglobin?
- AD. Myoglobin has a sigmoidal binding curve, while hemoglobin has a hyperbolic curve.
- BC. Myoglobin is a monomer, while hemoglobin is a tetramer.
- CB. Myoglobin binds oxygen in a cooperative manner, while hemoglobin does not.
- DA. Myoglobin is a tetramer, while hemoglobin is a monomer.
144Which of the following describes the Beer-Lambert Law in spectroscopy?
- AD. It calculates the molecular weight of dissolved substances.
- BC. It measures the fluorescence of molecules in a sample.
- CB. It relates absorbance to concentration, with higher concentrations leading to higher absorbance.
- DA. It quantifies the amount of light emitted by a sample.
145What is the significance of HisF8 in the structure of myoglobin and hemoglobin?
- AD. It binds Fe out of the plane of the haem, affecting oxygen binding.
- BC. It helps in the distortion of gas binding to allow dissociation.
- CB. It stabilizes the Fe atom in the haem group.
- DA. It binds to the oxygen molecule directly.
146How does hemoglobin's oxygen binding curve differ from myoglobin's?
- AD. Both hemoglobin and myoglobin have sigmoidal curves.
- BC. Both hemoglobin and myoglobin have hyperbolic curves.
- CB. Myoglobin has a hyperbolic curve, while hemoglobin has a sigmoidal curve.
- DA. Hemoglobin has a hyperbolic curve, while myoglobin has a sigmoidal curve.
147What is the structural difference between deoxyhaemoglobin and oxyhaemoglobin?
- AD. Oxygen binding does not cause any conformational changes in haemoglobin.
- BC. Both deoxyhaemoglobin and oxyhaemoglobin have a flat haem structure.
- CB. Deoxyhaemoglobin has a dished haem, while oxyhaemoglobin has a flat haem.
- DA. Deoxyhaemoglobin has a flat haem, while oxyhaemoglobin has a dished haem.
148What happens to helix F when oxygen binds to haemoglobin?
- AD. It detaches from the haemoglobin structure.
- BC. It moves toward the haem group, pulling histidine F8 with it.
- CB. It remains in the same position.
- DA. It moves away from the haem group.
149Which state of haemoglobin has a higher affinity for oxygen?
- AD. Neither state binds oxygen effectively.
- BC. Both T-state and R-state have equal affinity for oxygen.
- CB. R-state (relaxed state)
- DA. T-state (tense state)
150What is the effect of BPG (2,3-bisphosphoglycerate) on haemoglobin?
- AD. It does not affect haemoglobin’s function.
- BC. It binds to oxy-haemoglobin, enhancing oxygen binding.
- CB. It stabilizes the T-state, reducing haemoglobin’s oxygen affinity.
- DA. It increases haemoglobin’s affinity for oxygen.
151Why does fetal haemoglobin have a higher affinity for oxygen than adult haemoglobin?
- AD. Fetal haemoglobin is not influenced by CO₂ and pH levels.
- BC. It has fewer haem groups, making oxygen binding easier.
- CB. It binds less tightly to BPG, allowing for more effective oxygen transfer from maternal to fetal blood.
- DA. It is more sensitive to BPG.
152What is the primary difference between pharmacology and toxicology?
- AD. Toxicology deals with small molecules, while pharmacology deals with large molecules.
- BC. Pharmacology only studies effects at the molecular level, while toxicology focuses on the patient level.
- CB. Pharmacology studies drug effects, while toxicology studies harmful chemical effects.
- DA. Pharmacology focuses on harmful effects, while toxicology focuses on beneficial effects.
153Which of the following substances can affect proteins?
- AC. Venoms
- BD. All of the above
- CB. Alcohol
- DA. Antibiotics
154Which statement is true about enzymes?
- AA. Enzymes typically have multiple binding sites.
- BB. Enzymes bind ligands and release them unchanged.
- CC. Enzymes have one active site and convert substrates into products.
- DD. Enzymes are only involved in signal transduction.
155What is the role of an antagonist in receptor binding?
- AD. It breaks down ligands after binding.
- BC. It binds to the receptor and induces a cellular response.
- CB. It prevents receptor activation by blocking the agonist.
- DA. It activates the receptor.
156Which receptor class is involved in signal transduction through G proteins?
- AD. Voltage-gated ion channels
- BC. Receptor Tyrosine Kinases (RTKs)
- CB. G Protein-Coupled Receptors (GPCRs)
- DA. Ligand-gated ion channels
157What is signal transduction?
- AD. The synthesis of new receptors in response to ligand binding.
- BC. The process of deactivating receptors after ligand binding.
- CB. The series of steps where an active receptor triggers intracellular responses.
- DA. The direct movement of molecules through the cell membrane.
158What is the role of second messengers in signal transduction?
- AD. They facilitate ligand dissociation from the receptor.
- BC. They bind to receptors and inhibit their function.
- CB. They help relay signals from receptors to other intracellular proteins.
- DA. They directly activate the receptor.
159Which of the following is an example of a second messenger?
- AD. Glycogen
- BC. Glucose
- CB. Cyclic AMP (cAMP)
- DA. Insulin
160What is the process of phosphorylation in signal transduction?
- AA. The removal of phosphate groups from proteins.
- BB. The addition of phosphate groups to proteins by protein kinases.
- CC. The inactivation of receptors.
- DD. The breakdown of ligands after signal transmission.
161What type of receptor uses G proteins to relay signals within the cell?
- AA. Receptor Tyrosine Kinases (RTKs)
- BB. Ligand-gated Ion Channels
- CC. G Protein-Coupled Receptors (GPCRs)
- DD. Nuclear Receptors
162What are two main factors influencing the choice of a system for protein production?
- AA. Protein size and color
- BB. Financial reasons and biochemical complexity
- CC. Environmental impact and protein function
- DD. Availability of materials and speed of production
163What is one of the reasons for engineering proteins in biotechnology?
- AA. To decrease protein solubility.
- BB. To create simpler proteins.
- CC. To improve therapeutic outcomes.
- DD. To increase cellular toxicity.
164Which of the following is not a step in the protein design process?
- AA. Identify a need
- BB. Target selection
- CC. Degrade the protein
- DD. Expression and purification
165Gene therapy has the potential to permanently treat diseases by:
- AD. Blocking protein synthesis in cells.
- BC. Replacing enzymes with small molecules.
- CB. Inserting recombinant genes using viral vectors.
- DA. Eliminating the need for proteins.
166What is an example of a disease that could be treated with gene therapy?
- AD. Hypertension, by eliminating blood pressure proteins.
- BC. Obesity, by removing all fat cells.
- CB. Heart disease, by replacing heart muscle with plant proteins.
- DA. Diabetes, through reprogramming pancreatic α-cells to act like insulin-producing β-cells.
167What is the first step in producing recombinant proteins?
- AA. Clone the gene into an expression vector
- BC. Isolate the gene of interest
- CD. Transform bacteria with the protein
- DB. Purify the protein
168Which of the following is a disadvantage of prokaryotic expression systems for recombinant protein production?
- AA. Low yield
- BB. Pathogen contamination
- CC. Lack of post-translational modifications
- DD. High cost
169In recombinant insulin production, how are the insulin A and B chains expressed?
- AA. Together in mammalian cells
- BB. Separately in bacterial cells
- CC. As a single chain in yeast
- DD. Combined in plants before purification
170What is one key advantage of using mammalian systems for recombinant protein production?
- AB. Pathogen-free production
- BC. Ability to perform complex post-translational modifications
- CD. Rapid protein expression
- DA. Low cost and high yield
171Why is recombinant erythropoietin (rhEPO) produced in mammalian cells?
- AD. To avoid bacterial contamination
- BC. To reduce the production costs
- CB. Because it requires glycosylation for proper function
- DA. Because of the higher protein yield in mammalian cells
172What is the key process involved in recombinant DNA technologies?
- AA. Separating DNA from proteins
- BB. Joining DNA from different sources and inserting it into organisms
- CC. Creating DNA mutations in living organisms
- DD. Sequencing DNA using next-generation techniques
173Which of the following is considered a major historical milestone in recombinant DNA technologies?
- AA. The discovery of the polymerase chain reaction (PCR)
- BB. The discovery of the DNA double helix in 1953
- CC. The discovery of restriction enzymes in 2009
- DD. The first successful CRISPR-Cas9 experiment in 1972
174Which tool in recombinant DNA technologies is responsible for cutting DNA at specific sequences?
- AB. Plasmids
- BA. DNA Ligase
- CC. PCR
- DD. Restriction Enzymes
175What is the role of the "origin of replication (ORI)" in a plasmid used for recombinant DNA technology?
- AA. To enable the plasmid to replicate independently
- BD. To promote gene expression
- CC. To cut DNA into fragments
- DB. To select cells with successful transformations
176What is the primary difference between monogenic and polygenic traits?
- AC. Monogenic traits are controlled by a single gene, while polygenic traits are influenced by multiple genes and often environmental factors.
- BD. Monogenic traits are complex, while polygenic traits follow simple dominant/recessive inheritance.
- CB. Monogenic traits are influenced by environmental factors, while polygenic traits are purely genetic.
- DA. Monogenic traits are influenced by multiple genes, while polygenic traits are controlled by a single gene.
177Which of the following is an example of a continuous polygenic trait?
- AA. Eye color
- BB. Height
- CC. Phenylketonuria (PKU)
- DD. Hemophilia A
178Which of the following is a dichotomous trait?
- AD. Blood cholesterol levels
- BC. Myopia (nearsightedness)
- CB. Skin pigmentation
- DA. Asthma severity
179What percentage of genetic contribution is typically associated with asthma according to the provided examples?
- AD. ~80%
- BC. ~65%
- CB. ~50%
- DA. ~35%
180Which of the following diseases is considered polygenic and influenced by both genetics and environment?
- AA. Phenylketonuria (PKU)
- BB. Type-2 diabetes
- CC. Hemophilia A
- DD. ALDH2 deficiency
181Which of the following is the first step in the process of translation?
- AD) Codon redundancy
- BC) Termination
- CB) Initiation
- DA) Elongation
182What is always the first amino acid in the polypeptide chain during translation?
- AA) Glycine
- BB) Valine
- CC) Methionine
- DD) Lysine
183Which part of translation involves the ribosome adding amino acids to the growing polypeptide chain?
- AA) Initiation
- BB) Elongation
- CC) Termination
- DD) Phosphorylation
184What signals the end of the translation process?
- AA) Start codon
- BB) Redundant codon
- CC) Stop codon
- DD) Spliceosome
185What is a codon?
- AA) A sequence of three amino acids in a protein.
- BB) A sequence of three nucleotides in mRNA.
- CC) A section of DNA that regulates protein folding.
- DD) A protein complex that edits mRNA.
186A single base change in the DNA sequence is known as:
- AA) SNP (Single Nucleotide Polymorphism)
- BB) InDel (Insertion-Deletion)
- CC) Missense variant
- DD) Codon redundancy
187Which type of genetic variant can result in a stop codon and a truncated protein?
- AB) Silent variant
- BC) Nonsense variant
- CD) Synonymous variant
- DA) Missense variant
188Which genetic variant is responsible for sickle cell anemia?
- AA) SNP in hemoglobin (E6V)
- BB) Agouti signaling protein deletion
- CC) H64Y mutation in hemoglobin
- DD) Loss of uricase enzyme
189Which region of a gene is responsible for controlling gene expression by binding transcription factors?
- AA) Exons
- BB) Promoter
- CC) Introns
- DD) Transcribed region
190In eukaryotes, what happens to introns during mRNA processing?
- AB) They are spliced out of the mRNA.
. - BC) They remain as part of the final mRNA.
- CD) They are replicated alongside the DNA
- DA) They are translated into proteins.
- AB) They are spliced out of the mRNA.
191What enzyme is responsible for synthesizing mRNA during transcription?
- AD) Helicase
- BC) RNA polymerase
- CB) Ribosome
- DA) DNA polymerase
192What is the role of transcription factors in gene expression?
- AD) They package DNA into chromosomes.
- BC) They catalyze the translation process.
- CB) They bind to promoters to regulate RNA polymerase activity.
- DA) They splice introns from mRNA.
193Which of the following describes an activator transcription factor?
- AD) It splices introns out of mRNA.
- BC) It adds protective caps to mRNA.
- CB) It enhances the binding of RNA polymerase to the promoter.
- DA) It blocks RNA polymerase from binding to DNA.
194Why is transcriptional control important for cellular specificity?
- AD) It regulates the synthesis of DNA before cell division.
- BC) It allows cells to express only the necessary genes based on transcription factor availability.
- CB) It ensures the same genes are expressed in all cell types.
- DA) It determines the replication rate of DNA.
Information
- Description
- Biology Quiz on Biochemistry 192, created by Izelle Steyn on 10/09/2024.
- Author
- Izelle Steyn
- Language
- English
- Views
- 0
- Tags
- Rating
- No ratings yet Rate this quiz