2015 biochem midterm Flashcards
What percentage of the genome do repetitive elements contribute to?
a) 45%
b) 3.5%
c) 2%
d) 10%
a) 45%
Where can we find Satellite DNA?
a) Heterochromatin
b) LINEs
c) SINEs
d) Euchromatin
a) Heterochromatin
What leads to frame shift mutation?
a) Missense
b) Deletion
c) Inversion
d) Replication
b) Deletion
Deamination of cytosine is fixed by what repair mechanism?
a) Base Excision Repair
b) Nucleotide Excision Repair
c) Mismatch repair mechanism
d) DNA replication
a) Base Excision Repair
What is a characteristic of mRNA?
a) Make 15% of total RNA in cell
b) Make 80% of total RNA
c) Include modified bases
d) Monocistronic
d) Monocistronic
What is the purpose of using dd-NTP?
a) Base-Selective inhibition of DNA synthesis
b) Increases the rate the process
c) Minimize lost fragment
d) Repairs destroyed fragments
a) Base-Selective inhibition of DNA synthesis
What is the annealing temperature in the following primer: 5’ - AAA TTT AAG TGG CCG CCC - 3’ a) 54 C b) 56 C c) 73 C d) 24 C
a) 54 C
If we standardize the environment during the process of electrophoresis, what will the separation be based on?
a) size
b) charge
c) electrode quality
d) transport medium
a) size
Which part of tRNA attaches to amino acids?
a) Tau arm
b) anti-codon arm
c) acceptor arm
d) Modified bases arm
c) acceptor arm
Which of the following is characteristic of mRNA capping?
a) Linked in a 5’ to 5’ fashion
b) Poly A-tail
c) Helps in the splicing process
d) Hinders the transport of mRNA
a) Linked in a 5’ to 5’ fashion
What is the splice site at the 3’ site of an intron?
a) 5’ GU 3’
b) 5’ CG 3’
c) 5’ AG 3’
d) 5’ AC 3’
c) 5’ AG 3’
What is the primary site in the regulation of gene expression?
a) transcription
b) post-transcription
c) post-translation
d) DNA modification
a) transcription
What is the function of specific transcription factors?
a) Involved in transcription elongation
b) Involved in transcription initiation
c) Involved in transcription termination
d) Cis-acting molecules
b) Involved in transcription initiation
A pregnant agouti mouse has yellow coat, fat, and prone to diseases. However, when we introduce vitamin B diet supplements, its children are healthy. How did the diet make this change?
a) hypermethylation of agouti gene promoter
b) hypomethylation of agouti gene promoter
c) acetylation of agouti gene promoter
d) deacetylation of agouti gene promoter
a) hypermethylation of agouti gene promoter
In honey bee larvae, royal jelly is used to get worker bees and queen bee through DNMT gene hypermethylation. How are the target genes affected?
a) They will be hypermethylated
b) They will be hypomethylated
c) They will be acetylated
d) They will be deacetylated
b) They will be hypomethylated
When an antibiotic binds on 30s subunit on the A site, what will happen during translation?
a) inhibition of elongation
b) inhibition of initiation
c) inhibition of termination
d) cancer
c) inhibition of termination
I think it’s A
If the target sequence of a mitochondrial protein is cleaved, where will it go?
a. mitochondria
b. ER
c. nucleus
d. cytosol
a. mitochondria
What is the function of chaperones?
a) bind to exposed hydrophobic aa
b) bind to exposed hydrophilic aa
a) bind to exposed hydrophobic aa
Abrupt disruption of secondary protein structure forms which of the following?
a) A – helices
b) B – sheet
c) B – turn
d) Proline
c) B – turn
Tertiary structure of protein is stabilized mostly by which of the following?
a) C terminus
b) N terminus
c) peptide bond
d) side chains interaction
d) side chains interaction
What is the function of a catalyst?
a) lowering energy of products
b) b- lowering energy of substrates
c) lowering energy of transition state
d) Lowering the free energy
c) lowering energy of transition state
If we put 0.1 mM of inhibitor drug on a sample where the Km was 0.5 and vmax was 20, and this inhibitor is non-competitive. What is correct regarding km and vmax after this whole process?
a) vmax = 20, km = 5
b) vmax = 10, km = 0.5
c) vmax = 20 , km = 5
d) vmax = 10 and km = 2.5
b) vmax = 10, km = 0.5
Cooperativity gives the sigmoid shape that differs from michaelis-menten equation. What is the characteristic of enzymes that uses cooperativity?
a) narrow change in substrate concentration leads to a big change in reaction rate
b) high affinity at low concentration
a) narrow change in substrate concentration leads to a big change in reaction rate
Glycogen synthase uses which of the following substrates to make glycogen chain?
a) glucose-1-p
b) glucose-6-p
c) UDP-glucose
d) UTP-glucose
c) UDP-glucose
What determines the direction of a certain reaction pathway?
a) Summation of delta G in each step of the pathway
b) The delta G of the first step
c) The smallest delta G
d) The largest delta G
a) Summation of delta G in each step of the pathway
Which of the following metabolites is mostly used in cells for the transfer of energy?
a) ADP
b) ATP
c) NAD+
d) NADP
b) ATP
Phenylketonuria is which type of inherited metabolic disorders?
a) disorders of amino acid
b) disorders of carbohydrates
c) disorders of lipids
d) disorders of hormones
a) disorders of amino acid
Phenylketonuria is mostly caused due to which type of mutation?
a) inversion
b) deletion
c) insertion
d) missense
d) missense
Creutzfeldt-Jakob mad cow disease is due to a change in which of the following protein secondary structures?
a) B sheets
b) A helices
c) B turns
d) No repetitive secondary structure
a) B sheets
What ion’s movement is faulty in Cystic Fibrosis?
a) Ca
b) Cl
c) H
d) Li
b) Cl
What unwinds the supercoiled DNA during replication?
a) helicase
b) topoisomerase
c) DNA polymerase
d) histones
b) topoisomerase
Which enzyme is responsible for synthesis of the leading DNA strand?
a) DNA polymerase alpha
b) DNA polymerase Beta
c) DNA polymerase Gamma
d) DNA polymerase Delta
a) DNA polymerase alpha
If a bacterium lacks restriction enzymes. What could happen?
a) Not able to restrict growth of viral DNA
b) Hypermethylation of bacterial DNA
c) Bacterial plasmid cannot be integrated
d) development of bacterial resistance
a) Not able to restrict growth of viral DNA
Translocation of what two chromosomes gives you the Philadelphia gene in chronic myeloid leukemia?
a) Translocation between chromosome 7 and 22
b) Translocation between chromosome 8 and 22
c) Translocation between chromosome 9 and 22
d) Translocation between chromosome 10 and 22
c) Translocation between chromosome 9 and 22
BCR-ABL protein is defective in phosphorylation of what amino acid?
a) Tyrosine
b) Serine
c) Threonine
d) Lysine
a) Tyrosine
What metallic ion is needed to maintain cross-linking in a collagen protein?
a) sodium (Na)
b) copper (Cu)
c) magnesium (Mg)
d) lithium (Li)
b) copper (Cu)
What is required for the hydroxylation of proline residues in procollagen?
a) Vitamin D
b) Vitamin A
c) Vitamin K
d) Vitamin C
d) Vitamin C
What is the function of the negative charge on DNA in the process of electrophoresis?
a) stabilization of DNA
b) driving force
c) reducing the waste product
d) killing bacteria
b) driving force
If we perform 10 cycles of PCR using a single primer, how many folds will we get?
a) 10-folds
b) 100-folds
c) 1000-folds
d) 10000-folds
a) 10-folds
Which of the following protein structures is affected in sickle cell anemia?
a) primary structure
b) secondary structure
c) tertiary structure
d) quaternary structure
a) primary structure
Which amino acid is phosphorylated by ATP?
a) Lysine
b) Serine
c) Alanine
d) Asparagine
b) Serine
Phosphorylation of what amino acid changes the activity of an enzyme?
a) phenylaniline
b) phosphate
c) threonine
d) Glutamine
c) threonine
serine, threonine or tyrosine
Which of the following doesn’t induce glycogen degradation in the muscle?
a) Epinephrine
b) Glucagon
c) High blood sugar
b) Glucagon
If one parent is a carrier and the other parent is normal, what is the percent of children with cystic fibrosis?
a) 0%
b) 25%
c) 50%
d) 100%
a) 0%
RNA polymerase II creates which of the following?
a) snoRNA
b) tRNA
c) mRNA
d) rRNA
c) mRNA
What initiates DNA & creates primers?
a) DNA polymerase A
b) Helicase
c) Gyrase
a) DNA polymerase A
What stabilizes aatRNA when it’s added to the A-site?
a) Ts
b) Tu
c) EFG
b) Tu
What senses wrong folding in a protein (tags with glucose)
a) Glucosidase I
b) Glucosidase II
c) Glycosyltransferase
c) Glycosyltransferase
What characterizes a prion?
a) multiple A helices
b) multiple B sheets
c) abnormal primary structure
b) multiple B sheets
What bonds are broken when an egg is cooked?
a) Peptide bonds
b) non-covalent bonds
c) amide bonds
b) non-covalent bonds
