2016 biochem midterm Flashcards
What is the fate of primers used in a PCR reaction?
A. Becomes part of the amplified DNA
B. Becomes covalently attached to taq DNA polymerase
C. Helps in the denaturation of DNA
D. Gets removed at the end of the PCR
A. Becomes part of the amplified DNA
What is the cause of base selective inhibition of DNA in DNA sequencing?
A. dNTP
B. ddNTP
C. Primer
B. ddNTP
Which temperature depends on the primer length and structure? A. Denaturation temperature B. Annealing temperature C. Extension temperature D. Storage temperature
B. Annealing temperature
What will happen if we use 2 primers in DNA Sequencing?
A. We would get fragments with same size and same color
B. We would get fragments with same size but different colors
C. The taq polymerase will degrade
D. The won’t produce any fragment
B. We would get fragments with same size but different colors
What’s the role of acceptor arm of a t-RNA? A. Accepting amino acids B. Peptidase activity C. Proof-reading D. Reading genetic code
A. Accepting amino acids
If an antibiotic inhibits translocation during translation, what will happen to the polypeptide?
A. Full-length polypeptide will be produced
B. Frame of polypeptide will be changed
C. Premature polypeptide
D. Substitution
C. Premature polypeptide
If there is a mutation in the target sequence gene of a peroxisomal protein, where will the protein end up in? A. Cytosol B. Peroxisome C. Mitochondria D. Blood
A. Cytosol
What’s the reason for the presence of an active secretory protein lacking a signal peptide?
A. Signal peptide was removed in ER
B. Signal peptide in the gene was mutated
C. Signal peptide is not required in secretory proteins
D. Signal peptide was removed in Golgi apparatus
A. Signal peptide was removed in ER
What happens to a protein when it is boiled? A. Primary structure is lost B. Peptide bonds are hydrolyzed C. Non-covalent bonds are broken D. -S-S- interactions are disrupted
C. Non-covalent bonds are broken
Which of these forces stabilizes the secondary structure of a protein? A. H bonds B. Disulfide (S-S) bonds C. Hydrophobic interactions D. Ionic bonds
A. H bonds
What is the minimum number of amino acids required to form an alpha helix? A. 2 B. 4 C. 8 D. 12
B. 4
What is responsible for the cross-linking between lysine in collagen?
A. Cu
B. Fe
C. Vitamin D
A. Cu
What DNA modification is responsible for global silence gene? A. 3’ methyl C in -CpG- repeats B. 2- 3’ methyl ribose in -CG- C. 3- 5’ methyl C in -CpG- islands D. 4- 5’ methyl ribose in -CpG- repeats
C. 3- 5’ methyl C in -CpG- islands
Honey bee larva develops into queen bee if they are given royal jelly diet, what occurs during this process?
A. Hypermethylation of DNMT gene and activation of target genes
B. Hypermethylation of DNMT gene and suppression of target genes
C. Hypomethylation of DNMT gene and activation of target genes
D. Hypomethylation of DNMT gene and suppression of target genes
A. Hypermethylation of DNMT gene and activation of target genes
What causes Sickle cell anemia?
a. Change in the primary structure of b globin gene
b. Change in the secondary structure of b globin gene
c. Change in the tertiary structure of b globin gene
a. Change in the primary structure of b globin gene
A change in which type of protein structure in a prion protein causes Creutzfeldt-Jakob disease? A. Primary B. Secondary C. tertiary D. Quaternary
B. Secondary
What happens to the enzyme activity when a reversible inhibitor drug is added to its active site? A. Increase Km B. Decrease Km C. Increase Vmax D. Decrease Vmax
A. Increase Km
What binds most tightly to the active site of an enzyme?
A. Transition state analog
B. Reversible inhibitor
C. Irreversible inhibitor
A. Transition state analog
How does an allosteric effector alter the enzyme's activity? A. Blocks the active site B. Stabilizes the enzyme configuration C. Removes phosphate groups D. Disrupts -S-S- linkage
B. Stabilizes the enzyme configuration
Which amino acids are phosphorylated?
A. Serine
B. Glycine
C. Lysine
A. Serine
What metabolite is the major transporter of energy from anabolic to catabolic pathways? A. ATP B. GTP C. NAD+ D. NADP+
A. ATP
What determines the overall direction of a pathway with enzyme controlled steps?
A. Delta G of the first step
B. Delta G of the last step
C. Most negative delta G
D. The summed delta G of the whole pathway
D. The summed delta G of the whole pathway
Which substrate is used by glycogen synthase to make glycogen? A. ADP glucose B. Glucose C. Glucose-6-P D. UDP-glucose
D. UDP-glucose
What is the major product of glycogen degradation in muscles? A. Glucose B. Glucose 1 phosphate C. Maltose D. UDP glucose
B. Glucose 1 phosphate
What’s the ribozyme function?
A. Catalytic
B. Nucleotide modifier
C. Protein coding
A. Catalytic
What is the 5’ to 5’ type of bond between the cap and the +1 nucleotide? A. Monophosphate B. Diphosphate C. Triphosphate D. Tetraphosphate
C. Triphosphate
Which type of gene expression regulation is signaled by the intracellular glucocorticoid receptor? A. Post transcription B. Post translation C. Transcription D. Translation
C. Transcription
What is characteristic of housekeeping genes?
Continually expressed
What characterizes inborn errors of metabolism?
A. Fatal
B. Monogenic
C. Can be treated by diet
B. Monogenic
What is characteristic of phenylketonuria?
A. Elevated levels of phenylalanine
B. Hyperactivity of phenelalaninhydroxase
C. Autosomal dominant
A. Elevated levels of phenylalanine
What is true about cystic fibrosis? A. An obstructive disorder B. Affect the circulation C. Causes bleeding D. Treated with diet restriction
A. An obstructive disorder
Approximately what is the percentage of retrotransposons in human genome? A. 2 B. 41 C. 60 D. 98
B. 41
Where are tandem repeats found? A. Euchromatin B. Telomeres C. Nuclear envelop D. Heterochromatin
D. Heterochromatin
What DNA repairing system can correct oxidative deamination in DNA?
A. Base excision repair
B. Nucleotide excision repair
C. Mismatch repair system
A. Base excision repair
What is the type of mutation where a codon coding for a specific amino acid changes to a stop codon? A. Missense mutation B. Nonsense mutation C. Deletion mutation D. Frame shift mutation
B. Nonsense mutation
What kind of enzyme telomerase is? A. Reverse transcriptase B. RNA polymerase C. Endonuclease D. Exonuclease
A. Reverse transcriptase
Which polymerase has a primase activity? A. Polymerase alpha B. Polymerase beta C. Polymerase gamma D. Polymerase delta
A. Polymerase alpha
What is characteristic of restriction enzymes?
Palindrome
the same when read backwards
What trait of DNA fragments determines the speed of their separation by gel electrophoresis?
A. Length
B. Charge
C. Nucleotide sequence
A. Length
Chronic myeloid leukemia is due to a chromosomal translocation between A. Chromosome 9 and 11 B. Chromosome 11 and 22 C. Chromosome 9 and 22 D. Chromosome 7 and 11
C. Chromosome 9 and 22
What enzyme is dysregulated due to BCR-ABL fusion gene? A. Tyrosine kinase B. Tyrosine phosphatase C. Serine/threonine kinase D. Nitogen activated protein in kinase
A. Tyrosine kinase
