BIOL 416
Which of the following monomer building blocks is necessary to assemble membrane structure of eukaryotic cells? (a) sugars (b)fatty acids (c)amino acids (d)nucleotides
(b)fatty acids
Modern eukaryotes depend on mitochondria to generate most of the cells ATP. How many molecules of ATP can a single molecule of glucose generate In Cell? (a) - 20 (b) -2 (c) - 30 (d) -36
(c) - 30
Which of the following is not true? (a)Enzymes will not change its conformation before and after catalysis (b)Enzymes lower the activation energy for a specific reaction (c)Enzymes cannot control directions of specificity of reaction (d)Enzymes can be regulated by allosteric mechanism
(c)Enzymes cannot control directions of specificity of reaction
Which of the following statements if false? (a) Chromosomes were thought to carry heritable information based on microscopic analysis of mitosis (b) A full set of chromosomes in the organism is called the karyotype (c)Karyotype represents number and shape of chromosomes in each species (d)Karyotype of closely related species are always simliar
(d)Karyotype of closely related species are always simliar
Which statement is not true about a fluorescent microscope? (a)requires two sets of filters which limit wavelength of light (b)can be used to visualize specific proteins in speciment (c)can be used for monitoring movement of cellular proteins (d)can reach resolution beyond limitation of light microscope (200nm)
(d)can reach resolution beyond limitation of light microscope (200nm)
The second law of thermodynamics states that events of the universe will follow the directions of increasing _______, which means increasing disorder. The cellular activity of making biomolecules by a _________ reaction goes against that statement. To overcome this, the cell generates _______ which is release into the environment and increases disorder.
Entropy, Condensation, Heat
Which of the following membrane lipids makes membranes more stiff? a- phosphatidylcholine b- cholesterol c- phosphatidylserine d- phosphatidylethanolamine
b- cholesterol
Which of the following membrane proteins in the mitochondria does not use a protein gradient for its function? (a) - Pyruvate channel on outer membrane (b) - Phosphate channel on inner membrane (c) - Pyruvate channel on inner membrane (d) - F1/F0 ATP synthase
(a) - Pyruvate channel on outer membrane
From the delta g values provided in question 16, if cells can utilize all energy from version of glucose to Co2+water to create atp, how many ATP molecules can be made from one glucose molecule? (a) 93 (b)100 (c)10 (d)930
(a) 93
Which of the following nucleotide will not be used by cells to make nucleic acids (DNA or RNA)? (a)dUTP (b)ATP (c)CTP (d)dTTP
(a)dUTP
Which of the following statements is false? (a) - Total energy released from complete oxidation of sugar is the same as burning of sugar and the stepwise oxidation of sugar in cells (b) - Acetyl CoA is created intermembrane space of mitochondria (c) - Oxygen is required for initial reaction of electron transfer in mitochondria (d) - Malonate is used to inhibit Citric acid cycle for proving reaction is cycled
(b) - Acetyl CoA is created intermembrane space of mitochondria
The mitochondrial ATP synthase consist of several different protein subunits. Which subunit binds to ADP + Pi and catalyzes the synthesis of ATP as a result of a conformational change? (a) - F0 ATPase Head (b) - F1 ATPase head (c) - peripheral stalk (d) - central stalk
(b) - F1 ATPase head
Which of the following statements about allostery is false? (a) Binding of allosteric regulators affects the shape of a protein (b) Allosteric regulation is always used for negative regulation of enzyme activity (c) Modification of protein can be used as allosteric regulation (d)The allosteric regulator binding site of the enzyme can be located far away from the activity center of the enzyme
(b) Allosteric regulation is always used for negative regulation of enzyme activity
Which one of the following statement is not true? (a) Post-translation modification of a protein can regulate interactoins between this protein and its binding partner (b)Methylation of Lysine affects its electrical charge at its side chain (c) Binding affinity of a motor protein to its track can be changed during its ATP hydrolysis reaction (d) The shape of GTP bound form of small GTPase proteins is distinct from the shape of GDP bound form
(b)Methylation of Lysine affects its electrical charge at its side chain
Based on the relationship between reaction rates and substrate concentration for an enzyme-catalyzed reaction discussed in class, what the the Km value indicate with respect to enzyme-substrate interactions? (a)The maximum rate of catalysis (b)the enzyme-substrate binding affinity (c)the number of enzyme active sites (d)the equilibrium rate of catalysis
(b)the enzyme-substrate binding affinity
Which of the following statements about electron transfer is false? (a) - Three mitochondrial electron transport complexes of the mitochondria all act as a proton pump (b) - Three electron transport complexes of mitochondria are positioned to follow the order of redox potential of electrons (c) - Two electron transfer systems in chloroplast are used to create proton gradient across membrane (d) - Ubiquinone, an electron carrier molecule, has a hydrophobic tail for anchoring to the mitochondrial membrane
(c) - Two electron transfer systems in chloroplast are used to create proton gradient across membrane
Which following statement of Eukaryotic cells is false? (a) Eukaryotic cells have more complex membrane structures than Prokaryotes (b) Genome of Eukaryotic cells is stored in nucleus during interphase (c) Eukaryotic cells do not have membrane protein that forms b-barrel structure (d) Nuclear of Eukaryotic cells has high density so that can be separated from other cellular organelles by spinning cell extracts at low speed
(c) Eukaryotic cells do not have membrane protein that forms b-barrel structure
Which of the following statements about chromatin is false? (a) Chromatin is a chain of nucleosomes that is composed of a histone core and DNA (b)Each nucleosome caintains 8 histone proteins and -147 base pairs of DNA (c) Histone in nucleosomes are cmoposed of two molecules each' H1, H2A, H2B, and H3 (d) A DNA fragment wrapped around a nucleosome is not easily accessible by a sequence specific DNA binding protein, such as a transcription factor
(c) Histone in nucleosomes are cmoposed of two molecules each' H1, H2A, H2B, and H3
Which statement is false about protein structure? (a)primary structure of protein can be determined by DNA sequence of the gene coding that protein (b) Proline is usually located in unstructured regions (outside of secondary structured regions) of the proteins (c) Tertiary structure of protein will not be affected whether proteins are in organic solvent of in water (d) Disulfide bond can be used to link two proteins
(c) Tertiary structure of protein will not be affected whether proteins are in organic solvent of in water
Which of the following statements about DNA replication of a human chromosome is false? (a) It is synthesized from multiple origins on the chromosomes (b) It is synthesized from multiple origins by a mixture of continuous and discontinuous DNA synthesis (c) The template DNA sequence is completely replicated (d) Modification of both DNA and Histones on template will be maintained after DNA replication
(c) The template DNA sequence is completely replicated
Proteins are made by a condensation reaction of amino acids. If a protein has 100 amino acids, how many variations in primary structure could it have? (a)20 x 100 (b)4 x 100 (c)20^100 (d)100^20
(c)20^100
Which of the following group of enzymes can catalyze energetically uinfavorable reaction? (a) hydrolase (b)protease (c)ligase (d)phosphatase
(c)ligase
Which modification on the side chain of lysine is observed in cells? (a)acetylation (b)ubiquitination (c)methylation (d)all of the above
(d)all of the above
As we discussed in class, linear genomes (eukaryotes) have problems replicating DNA completely. In theory, which of the following (enzyme) activites can solve this problem? (a)Dnaprimase that can synthesize DNA primers for initiation of DNA replication (b) DNA polymerase that can extend DNA strand from 5' end (c)DNA polymerase that does not require intial RNA primer (d)any of the above
(d)any of the above
Which the following statements is true? (a) - Carbon fixation can be described as a process by which gaseous carbon-containing molecules are captured and incorporated into biological hydrocarbon molecules (b) - RUBISCO is required for initial gaseous carbon-containing molecules capturing reaction (c) - Carbone fixation reaction (Kelvin-cycle) only happened when sunlight is available (d) - During carbon fixation cycle, one molecule of a three carbon compound is released from the cycle
No count
Which of the following statements is true? a- A mutation is passed on to offspring only if it is present in the germ-line cells b- A heritable mutation that causes a disease, such as the breast cancer gene, initially happened in somatic cells of the individual then was inherited by offspring c- A mutation arises in a mother's somatic cell often causes a disease in her daughter d- In an evolutionary sense, a mutation in somatic cells plays important role in our evolution
a- A mutation is passed on to offspring only if it is present in the germ-line cells
Select the peptide sequence that can form a single transmembrane domain? a- ILVIMIVLVMLLLIMLAILAVHF B- ILVFFILVMPAVLFWMLIALLVE C- VGHSDSIFTLNVISLRGIFVFFEL D- VTLHKNMFLTDYILENSMIIIILL
a- ILVIMIVLVMLLLIMLAILAVHF
You discover that the underlying cause of a disease is to lessen the expression of a protein do to a lower amount of mRNA caused by mutation. this change is most likely due to? a- a mutation within an exon b- a mutation within the regulatory DNA, such as a promoter of a gene c- a mutation within the introns d- a mutation within the poly-A tail
b- a mutation within the regulatory DNA, such as a promoter of a gene
Which of the following does not fit is the function of the Golgi apparatus? a- Distribute lipid unevenly to lumen side and cytoplasmic side b- acquire new lipids from cytoplasm c- modification of lipids by sugar d- modification of membrane protein by sugar
b- acquire new lipids from cytoplasm
Which of the following about bacterial transcription is false? a- RNA polymerase requires sigma factor for initiating transcription b- mRNA transcribed from one promoter always codes on gene (protein) c- Sigma factor recognizes promoter sites in DNA d- Can be controlled by environmental factor, for example an available sugar source
b- mRNA transcribed from one promoter always codes on gene (protein)
Which of the following transcriptional regulators discussed in class is controlled by allosteric regulation? a- Cholesterol receptor b- repressor of lactose operon c- activator of lactose operon d - all of the above
d - all of the above
Which of the following enzymes is not required at the replication forks during DNA replication? a- dna polymerase b- Primase c- DNA Helicase d- DNA topoisomerase
d- DNA topoisomerase
Which of the following statements about microscopic analysis is false? (a) Electron microscope has lesser resolution than confocal microscope (b)Antibody can be used to visualize specific molecules in cells by combining fluorescent microscope (c) Confocal microscope can increase resolution of signal by limiting light path with Pinhole (d) Fluorescent proteins can be used to visualize movement of proteins in cell
(a) Electron microscope has lesser resolution than confocal microscope
Which of the following statement about heterochromatin is false? (a) Most likely contains heavily acetylated histones (b) Most likely contains histones H3 whose lysine 9 is methylated (c)could be located near telomeres (d)Has specific binding proteins that bind to modified histole tail
(a) Most likely contains heavily acetylated histones
Which of the following statements is false? (a) - Cells eliminate unwanted mitochondria by autophagy (b) - The outer mitochondrial membrane is less permeable than inner mitochondrial membrane (c) - The proton gradient across membrane is preferable made in cristae in mitochondria that intermmebrane space between inner membrane and outer membrane (d) - The inter-membrane space of cristae in the mitochondria is more acidic than that in the matric
(b) - The outer mitochondrial membrane is less permeable than inner mitochondrial membrane
In anaerobic conditions, yeast produces _____ (a) - lactate and co2 (b) - ethanol and co2 (c) - lactate only (d) -ethanol only
(b) - ethanol and co2
The ATP synthase found in chloroplasts is structurally similar to the F1/F0 synthase in mitochondria. Given that ATP is being synthesized in the stroma, where will the f1 portion of the ATP synthase be located? (a) - Thylakoid intermembrane space (b) - stroma (c) - inner membrane (d) - thylakoid membrane
(b) - stroma
Several different classes of enzymes are needed for the catabolism of carbohydrates. Which of the following classes of enzymes is not involved in glycolysis reactions? (a) - kinase (b) -protease (c) - isomerase (d) -mutase
(b) -protease
Carbohydrate (sugar) molecules are used in cells in many ways. Which of the following statement is false? (a) Condensed sugar (polysaccharide) is a major form of storing energy for cells (b) 6-carbone sugar (hexose) is a part of building block of a nucleotide (c) Sugar can be a structural support in cells (d) Sugars used in DNA and RNA are different
(b) 6-carbone sugar (hexose) is a part of building block of a nucleotide
The gene information stored in DNA is the sequence of _____ in a DNA strand, which is copied by ______ to be translated into _________ (a) bases, proteins, RNA (b)amino acid, RNA, Proteins (c)Bases, RNA, proteins (d)Sugar, RNA, Lipids
(c)Bases, RNA, proteins
Which following statement about chemical bonding is true? (a)strength of non-polar covalent bond is much lower in water than in vacuum (b)polar convalent bond can be formed between two atoms which has similar electronegativity (c)Hydrophobic interaction is medicated by exclusion of hydrophobic molecules by water (d)Strength of polar covalent bond is same as non-polar covalent bond in water
(c)Hydrophobic interaction is medicated by exclusion of hydrophobic molecules by water
Which of the following statements about the genome is false? (a)All the cells in your body have the identical genome (b)The number of genes coded in the human genome is similar to the number of genes in a mouse's genome (c)No amphibian or fish has a larger genome size than human (d)Human genome size is larger than a mouse's genome
(c)No amphibian or fish has a larger genome size than human
Which covalent bond between following combination of atoms (elements) could be electrically polar covalent bond? (a)Carbon-Carbon (b)Hydrogen-Carbon (c)Oxygen-Carbon (d)Oxygen-Oxygen
(c)Oxygen-Carbon
Phosphorylation of amino acids is used for many occasions in cells, as such signal transduction and regulation of enzyme activity. Which amino acids are known to be phosphorylated in eukaryotes? (a)Histidine, Serine, Tyrosine (b)Arginine, Lysine, Threonine (c)Serine, Threonine, and tyrosine (d)Histidine, Threonine, and tyrosine
(c)Serine, Threonine, and tyrosine
Which combination of words correctly fits in the blanks? "All living organism on earth use energy initially provided from ______, which is captured by ______." (a)Sunlight, Mitochondria (b)Carbon, Chloroplast (c)Sunlight, Chloroplast (d)Oxygen, MItochondria
(c)Sunlight, Chloroplast
Which of the following statements fits in the blank? "DNA double helix _________." (a) contains uridine (b)is formed by hydrophobic bonds between bases (c)has negative charged originated from phosphate backbone (d)Is made by two DNA strands that ran parallel
(c)has negative charged originated from phosphate backbone
Which of the noncovalent interactions below will contribute most to form core of globular proteins in water? (a)ionic bonds (b)hydrogen bonds (c)hydrophobic interactions (d)Van der Waals attractions
(c)hydrophobic interactions
Which of the following element is the most abundant in weight in bacteria? (a)hydrogen (b)carbon (c)oxygen (d)nitrogen
(c)oxygen
Which combination of words fit into the blanks of the following sentence? "Glycolysis expends energy from _____ at its ______ step of reaction. In the end, the net number of activated carrier molecules produced in this process are ______ and __________. (a) - GTP, last, 4 ATP, 2 NADH (b) - ATP, initial, 4 ATP, 4 NADH (c) - GTP, initial, 2 ATP, 2 NADH (d) - ATP, initial, 2 ATP, 2 NADH
(d) - ATP, initial, 2 ATP, 2 NADH
Which of the following statements is false? (a) - The pyruvate dehydrogenase complex catalyzes three different, but linked, enzymatic reactions (b) - Pyruvate dehydrogenase produces Acetyl CoA by oxidizing pyruvate (c) - Acetyl CoA has high-energy thioester bond (d) - Acetyl CoA is only produced from oxidizing sugar by glycolysis not from any other carbon compound
(d) - Acetyl CoA is only produced from oxidizing sugar by glycolysis not from any other carbon compound
Which of the following statements about mitochondrion and chloroplasts is false? (a) - They have circular DNA that carry some genes required for their functions (b) - Chloroplast might have been acquired to ancient eukaryotic cells earlier than mitochondria (c) - Genomic DNA in the nucleus has genes required for mitochondrial and chloroplast functions (d) - Both of them produce ATP that can be used by any reaction requiring ATP in cells
(d) - Both of them produce ATP that can be used by any reaction requiring ATP in cells
Which of the following statements about photosystem in chloroplast is false? (a) - Both photosystems are composed of an antenna complex and a reaction center (b) - Both photosystems can activate electrons to their high energy state by using energy from light (c) - The antenna complex cannot effectively acquire energy from green color light (d) - Both photosystems use same electron carrier molecules to deliver activated electrons to following reactions
(d) - Both photosystems use same electron carrier molecules to deliver activated electrons to following reactions
Which of the following statements about glycolysis is false? (a) - ATp is used to phosphorylate the carbohydrate during glycolysis (b) - Step 6 of glycolysis created NADH and that reaction is coupled to step 7 to generate ATP (c) - Hydrolysis of phosphate from phosphoenolpyruvate releases larger free energy than the free energy released by hydrolyzing ATP to ADP (d) - Oxygen is consumed during glycolysis in the cytosol
(d) - Oxygen is consumed during glycolysis in the cytosol
Which of the following process takes place in the mitochondria? (a) - citric acid cycle (b) - conversion of pyruvate to activated acetyl groups (Acetyl coa) (c) - Oxidative phosphorylation (d) - all of above
(d) - all of above
Which of the following statement does not fit in the blank? "Chromatin-remodeling complexes (Nucleosome remodeling proteins) ____________." (a) are motor proteins that use DNA as a track (b)can move core histones in chromatin to allow specific DNA sequence to be more accessible (c) use for energy of ATP hydrolysis in nucleosomes (d) Are capable of efficiently moving histones that have no modification on their tails
(d) Are capable of efficiently moving histones that have no modification on their tails
Which of the following statements about human chromosomes is false? (a) Each chromosome occupies discrete territories in the nucleus during interphase (b)Chromosome isolated from cancer patients often show an abnormality in the number of chromosomes and in the shape of the chromosomes (c)Condensation of chromatin to chromosomes is required for separation of the genome in mitosis (d) Each chromosome has a distinctive DNA sequence at its telomere
(d) Each chromosome has a distinctive DNA sequence at its telomere
Mitochondria and chloroplast are considered as prokaryotic parasites of ancient eukaryotic cells. Which following statement does no support this notion? (a) Contain DNA (b) Composition of lipids forming their membrane structures is different from other membranes in the cell (c) some of their membrane integrated protein form b-barrel structure (d) They contain ribosomes that are similar to eukaryotes
(d) They contain ribosomes that are similar to eukaryotes
We discussed several examples of allosteric regulation of protein function in class. Which of the following is an example of allosteric regulation? (a) Inhibition of an enzyme by CTP (b)Activation of the glucose digesting enzyme by ADP (c)Motor proteins movement on track by ATP binding and hydrolyisis (d) all of the above
(d) all of the above
Delta G circle indicates the change in the standard free energy as a reactant is converted to product. Given what you know about these values, which reactions is most favorable? (a) -7.3kcal/mole (b) -1.7kcal/mole (c) 5.5kcal/mole (d)-686kcal/mole
(d)-686kcal/mole
DNA polymerase that has a proofreading function possesses ______ accuracy in synthesizing a new DNA strand during DNA replication than DNA polymerase that does not have proof reading function (a)2-fold (b)5-fold (c)10-fold (d)100-fold
(d)100-fold
Cells often make energetically unfavorable reactions by using different mechanisms. Which of the following is a good example of that? (a) Using ATP hydrolysis to condense sugar to make a polysaccharide (b)Combining two sequential reactions, as such energetically unfavorable reaction followed by favorable reactions (c)Phosphorylation of proteins by a protein kinase (d)All of the above
(d)All of the above
Which of the following protein functions can be predicted from primary structure of proteins? (a) Whether the protein can bind to cAMP or not (b)Whether the proteins can form helix turn helix motif or not (c)Whether the protein can bind to GTP or not (d)All of the above
(d)All of the above
Secondary structures of proteins, alpha helix and beta sheets, are commonly observed in all proteins. What makes it possible for proteins to have these common structural elements? (a) Hydrophobic interaction between side chains of non-polar amino acids (b)Ionic bonds between side chains of polar amino acid (c) Van der waals attracitons of the atoms in side chains of any amino acids (d)Hydrogen bonds between nitrogen and oxygen on the backbone of amino acids
(d)Hydrogen bonds between nitrogen and oxygen on the backbone of amino acids
Which following statement does not correctly describe the behavior of a lipid molecule in water? (a)phospholipids can form lipid bilayers (b)lipids form micelle where the hydrophillic side is facing towards the water side (c)Triacylglycerol will form lipid droplet (d)Lipids can make a firm surface on water with their hydrophobic side facing toward water
(d)Lipids can make a firm surface on water with their hydrophobic side facing toward water
Which of the following statements about genetic model organisms is false? (a)Fission yeast mutants were used to study how mitosis is induced (b)The study about fruit fly mutant called "sevenless" revelead EGFR/Ras pathway (c)Most genetic model organisms have established mutant strains available to any researched (d)No plant is established as a genetic model organism
(d)No plant is established as a genetic model organism
Eukaryotic chromosomes contain sequence elements that are required for the faithful transmission of genetic information form a mother cell to each daughter cell. Which of the following is known to be one of these required elements in eukaryotes? (a) Centromeres (b) Origins of replication (c)telomeres (d)all of the above
(d)all of the above
Which of the following statements fit in the blank? "An ionic bond between two atoms, such as NaCl, is formed as the result of the ______," (a)sharing of electrons (b)loss of electrons from both atoms (c)loss of a proton from one atom (d)transfer of electrons from one atom to the other
(d)transfer of electrons from one atom to the other
The heterochromatin region of chromosomes is mediated by histone modifications. The current model to establish heterochromatin showed that enzymes initially recruited on the heterochromatin can extend the histone modifications to expand heterochromatin region. If cells need to stop the expansion of heterochromatin, what mechanism(s) can be used to stop expansion of heterochromatin at a specific position on chromosomes? Describe two possible mechanisms with a couple of sentences each. (3pts for each mechanism)
1.Putting barrier sequence next to heterochromatin regain. This sequence can eliminate Histones next to heterochromatin region therefore no histone modifications that are required for heterochromatin can not be extended beyond that sequence. (Need to explain potential function of barrier sequence for full point.) 2.Modify histone tails located next to heterochromatin to compete for making required modification for heterochromatin formation. For example, acetylation of histone tail makes histone less tightly bound to DNA thus compete to tight binding of histone tail for heterochromatin formation.
Which of the following statements is not true? (a) Converting ATP to AMP releases less energy than converting ATP to ADP (b)In general, hydrolysis does not require energy because the reaction is energetically favorable (c) Covalent bonds between carbons can be broken by increasing temperature in the presence of oxygen (d)Activity of an enzyme using ATP to make it an energetically unfavorable reaction can be regulated by concentration of ATP
Converting ATP to AMP releases less energy than converting ATP to ADP
You found two enzymes that catalyze the same hydrolysis reaction in the same substrate. You analyzed their activities and obtained results shown in the graphs below Based on these results, which enzyme (Enzyme #1 or Enzyme #2) will be more effective at hydrolyzing the substrate in the following cells? Explain your reasoning with couple of sentences. Cell A; Contains ~2 micro M of the substrates (4pts) Cell B; Contains ~10 micro M of the substrates (4pts)
For Cell A, Enzyme #1 will work better. At 2 micro M, Enzyme #1 has ~10mol/sec catalytic rate that is clearly faster than that of Enzyme #2 (~5mol/sec). For Cell B, both enzymes have similar catalytic rate at 10 micro M substrate concentration. Therefore, both enzymes might work equally in Cell B. (This is what I expected.. But most of you are more rigorous than me by looking into catalytic rate difference between two enzymes at 10 micro M. So, if you state "Enzyme #2 is better because it has slightly higher catalytic rate at given substrate concentration", you have full points.)
A protein can form its _________ by following their most energetically favorable conformation. Groups of proteins called __________aide in this process by binding to newly synthesized proteins. A _______ is one of these proteins which was identified as a critical pathogen in Mad Cow disease, which is caused by a misfolded protein.
Tertiary structure, Chaperones, Prion
Even with proof reading activity of DNA polymerase and mismatch repair mechanism, there will be a mistake in DNA replication on human cells replicate their genome. How many mistakes are expected after DNA replication happens in the human genome? a - 3 b - 30 c-300 d-3000
a- 3
Action potential is created by the movement of ions across the plasma membrane through a channel. The channel for ____ is critical to create an action potential. a- Na+ b- K+ c- Ca2+ d- Cl-
a- Na+
The inherited disease xeroderma pigmentosum causes serious problems with lesions on skin and often people with this disease develop skin cancer with repeated exposure to sunlight. Which of the following repair mechanisms affected in the cells of the individuals who have inherited this disease? a- Repairing Thymine dimer created by UV irradiation b- Repairing Double strand break created by X-ray c- Repairing chemical damage of base by base excision repair d- proof reading mechanism during DNA repliation
a- Repairing Thymine dimer created by UV irradiation
Which of the following occurs after a eukaryotic mRNA is exported from the nucleus? a- The ribosome binds to mRNA b- The mRNA is polyadenylated at its 3' end c- 7-mehtylguanosine is added at a 5' end of the mRNA d- Elimination of intron form initial transcript
a- The ribosome binds to mRNA
Which of the following statements is true? a- rRNAs and mRNA are transcribed by different RNA polymerases b- RNA polymerase II is mostly located in the nucleolus c- Non-protein-coding RNA, except tRNA and rRNA, do not have any function in cells d- RNA polymerase II only makes mRNAs, which code proteins
a- rRNAs and mRNA are transcribed by different RNA polymerases
Which of the following statements about nucleosomes is false? a- Position of core histones with respect to transcription factor binding site of the DNA can influence efficiency of binding of the transcription factor b - When the histone tail of nucleosomes is not modified, DNA is less tightly bound to Histone. c- Combination of Histone modifications (histone code) at nucleosomes is key epigenetic information d - Hetero-chromatin binding proteins bind to Histone H3 methylated at Lysine 9
b - When the histone tail of nucleosomes is not modified, DNA is less tightly bound to Histone.
Which of the following statements about transcriptional regulators is false? a- Transcriptional factors usually interact with the specific DNA sequence through noncovalent bonding b- A transcriptional factor only binds to unique sequences c- The bases in a DNA double helix is capable of forming noncovalent bonds to a protein still keeping hydrogen bonds between bases d- Eukaryotic transcriptional regulators can affect gene expression even if there is a large distance between them and the transcription intiation site
b- A transcriptional factor only binds to unique sequences
Which of the following statements about human genome is false? a- About 2-3% of DNA sequence among the entire genome is protein-coding exons b- Mobile elements are categorized as unique sequences c- About 50% of the genome is repeated sequence elements d- Genes (intron plus exon) occupy about 22% of DNA sequence among entire genome
b- Mobile elements are categorized as unique sequences
Which of the following transporter uses energy from sodium gradient for its transport reaction? a- Na+/K+ pump b- Na+/Glucose symport c- voltage gated Ca2+ channel d- Bacteriorhodopsin
b- Na+/Glucose symport
Which of the following is false regarding the structure and function of telomeric sequences? a- Telomere repeat sequences allow T-loop structure to form b- Non-homologous end joining repair mechanism can fuse intact telomeres (telomeres with t-loops structure) c- If a cell expresses telomerase, that cell can extend telomeric DNA d- Loss of t-loop structure can be mediated by loss of TRF2 protein
b- Non-homologous end joining repair mechanism can fuse intact telomeres (telomeres with t-loops structure)
Which of the following statements about slicing is false? a- some of small non-coding RNAs in the nucleus are necessary to perform the splicing reactions b- Spliceosome attaches to DNAs to cut an intron c- Overall reaction of splicing does not require energy even though it contains a condensation reaction d - Alternative splicing contributes to increase variation of mRNAs from initial transcript
b- Spliceosome attaches to DNAs to cut an intron
Which of the following statements about viruses is true? a- DNA viruses cannot affect cell division cycle in host cells b- Viral gnomes can be made of RNA or DNA c- Only RNA viral genomes can be integrated into host genome d- DNA virus need to have a reverse transcriptase for replicating their genome in host cells
b- Viral gnomes can be made of RNA or DNA
Which of the following statements is true? a- Gas, such as CO2 and O2, can diffuse across the cell membranes but not an artificial lipid bilayer b- Electrically charged molecules, such as ions, can diffuse through the artificial lipid biylayer c- Direction of passive transport of molecules across membrane is not only controlled by osmosis d- Active transport always uses energy from ATP hydrolysis to move a molecule across plasma membrane against osmosis
c- Direction of passive transport of molecules across membrane is not only controlled by osmosis
Which of the following mechanisms contributes the most in creating multifunctional domain proteins? a- Point mutation in an exon b- Point mutation in promoted region of genes c- Exon shuffling by transposon activity d- None of above
c- Exon shuffling by transposon activity
Which of the following statements about eukaryotic transcription regulators is true? a- All transcription regulators, which bind to specific DNA sequences, are specified to either repress gene expresison or activate gene expression b- Transcription repressor bing to HAT either directly or indirectly c- General transcription factor contain TBP d- Binding sequence of transcription regulator is always located close (within -200bps) to TATA box
c- General transcription factor TBP
Which of the following statements about membrane proteins is false? a- Membrane anchor protein does not recover its signal quickly by FRAP analysis b- Modification of proteins by linear carbon chain can make the protein locate to the mebrane c- Single amphipathic a-helix never makes a protein located on the membrane d- Theoretically, a 20 amino acids long helix is long enough to penetrate the lipid bilayer
c- Single amphipathic a-helix never makes a protein located on the membrane
Glycoproteins contribute to the carbohydrate layer on the surface of the cell. Which of the following is true about glycoproteins? a- The carbohydrate chain on glycoproteins can be made in cytoplasmic side of Golgi b- Their carbohydrate chains are observed in vesicles that transfer from ER to Golgi apparatus c- They are post of glycocalyx (carbohydrate layer of cell surface) d- They will repulse water molecule from the cell surface
c- They are post of glycocalyx (carbohydrate layer of cell surface)
Which of the following statements about retro transposon is false? a- Need to be transcribed first to move its position in the genome b- contains reverse transcriptase gene c- initially inserted into genome by DNA virus infection d- contains transposases (recombination enzyme) gene
c- initially inserted into genome by DNA virus infection
Which of the following structures about membrane proteins is the most appropriate to form a transporter protein on a eukaryotic plasma membrane? a- single transmembrane a-helix b- b-barrel c- multi-amphipathic transmembrane a-helices d- lipid monolayer inserted a-helix
c- multi-amphipathic transmembrane a-helices
Which of the following statements about small non-coding RNAs such as micro RNA, is false? a- some of the small noncoding RNAs can regulate translation efficiency of mRNA b- Some of small noncoding RNAs can bring proteins to specific location where it has a nucleotide sequence matching them c- small noncoding RNAs are made by RNA polymerase I d- some of the small noncoding RNAs reduce stability of mRNA in cytoplasm
c- small noncoding RNAs are made by RNA polymerase I
Membrane lipids are capable of many different types of movement. Which of these require energy to happen in biological membranes? a- rotation b- lateral movement c- switching between lipid layers d- flexing of hydrocarbon chains
c- switching between lipid layers
Related to epigenetic regulation like we discussed in class, which of the following statements is false? a- Methylation of DNA can serve as epigenetic information b- Epigenetic regulation is mainly mediated by specific proteins that recognize epigenetic information c- Combination of histone modifications plays an important role in epigenetic regulation d- In each individual, germ-line cells and neurons have identical epigenetic information
d- In each individual, germ-line cells and neurons have identical epigenetic information
Which of the following statements is true? a- Synaptic vesicles containing neurotransmitters will fuse to presynaptic membrane when Na+ concentration is increased b- Presynaptic membrane has ligand-gate Ca2+ channels c- Transmitting signals at synapses between presynaptic membrane and post synaptic membrane is mediated by releasing ions from presynaptic membrane d- Opening Cl- channel in postsynaptic membrane can antagonize induction of action potential by competing with the opening of a Na+ channel
d- Opening Cl- channel in postsynaptic membrane can antagonize induction of action potential by competing with the opening of a Na+ channel
Transcription is similar to DNA replication in that ______________? a- Nucleotide polymerization occurs only in 5'-3' direction b- energy required for condensation of nucleotides is provided from incoming nucleotides c- unwinding DNA double helix is required for initiating reaction d- all of above
d- all of above
Which of the following will be essential an intestinal epithelial cells to absorb glucose from the gut lumen and to release glucose to the inside of our body? a- Position of Na+/Glucose symport on apical side of plasma membrane b- Na+/K+ pump to create Na+ gradient c- Glucose transporter positioned at the basal side of the plasma membrane d- all of above
d- all of above
Which of the following mechanisms may not be used by cells to change patterns of gene expression? a- expression of transcription regulators that can increase its own expression b- changing histone modification c- eliminating DNA methylation d- changing DNA sequence during DNA replication
d- changing DNA sequence during DNA replication
Which of the following statements about IPS cells is false? a- iPs cells are created by adding 3 transcription regulators to a fibroblast b- iPs cells are created from mouse cells can differentiate into almost any mouse cell types c- iPs cells are similar to embryonic stem cells in terms of their potency to differentiate many different types of cells d- during the de-differentiation process to become an iPs cell, the fibroblast will not change its gene expression profile
d- during the de-differentiation process to become an iPs cell, the fibroblast will not change its gene expression profile
Which of the following statements does not fit in the blank? The distinct characteristics of different cell types in the multicellular organism result from the differential regulation of the __________? a- expression of transcription regulators b- histone codes on chromosomes c- modification of DNA by methylation d- genome sequence differences between cells
d- genome sequence differences between cells
Which of the following statements about tRNA is false? a- tRNA forms secondary structures based on base pairing b- depending on anti-codon sequence on tRNA, each tRNA carries a specific amino acid c- Aminoacyl-tRNA has a high energy bond that makes a condensation reaction for synthesizing protein on ribosome d- tRNA is transcribed by RNA polymerase II
d- tRNA is transcribed by RNA polymerase II