ASCP Molecular Biology Certification Exam Review
QUESTIONS AND ALL CORRECT ANSWERS
100% SOLVED AND GUARANTEED SUCCESS!!
Pyrimidine - answer--One carbon ring
Cytosine, Thymine, Uracil
Purine - answer--Two carbon rings
Adenine, Guanine
How are nucleotides joined together? - answer--Condensation to form
phosphodiester bond
What is the function of mRNA? - answer--Carries genetic info out of
nucleus
Transcript translated to protein
What is the function of tRNA? - answer--Carries aa to ribosome
Anticodon pairs with codon on mRNA strand
,What is the function of rRNA? - answer--part of ribosome structure
most abundant RNA
coordinated coupling of tRNA to mRNA codons
Feedback inhibition - answer--Product of pathway is noncompetitive
inhibitor
Binds to allosteric site to slow down rxn b/c too much product
Exonucleases - answer--Degrades nucleic acids by removing one
terminal nt at a time
Cleaves phosphodiester bond at end of chain
5' --> 3' and 3' --> 5'
Endonucleases (Prok) - answer--Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
ORI sites - answer--nt sequence where replication is initiated
Topoisomerase I - answer--Induces ss breaks
,Remove DNA supercoils during TXN and DNA replication; for strand
breakage during recombination; for chr condensation; and to
disentangle intertwined DNA during mitosis
topoisomerase II - answer--cuts both strands of one DNA double helix,
passes another unbroken DNA helix through it, and then reanneals the
cut strands
Gyrase (topoisomerase II) - answer--Unwinds supercoiling caused by
unwinding at the rep fork by introducing DSBs
Helicase - answer--Breaks H-bonds of double helix at the replication fork
Primase - answer--DNApol α (DNA dep RNA pol)
adds short segments of complementary
RNA to ssDNA template (primers), serves as starting points for
replication
single-strand DNA binding proteins (SSBPs) - answer--Binds ssDNA and
prevents it from re-annealing during TXN, replication, repair, and
recombination
, Okazaki fragments - answer--Short fragments of DNA synthesized by
DNApol δ using the lagging strand (3'->5') as a template
Ligase - answer--Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
What are the steps in DNA replication? - answer--1. Initiate
2. Elongate
3. Terminate
Telomeres - answer--Repeat sequence (TTAGGG) at the ends of chr,
protect chr from degradation
RNA polymerase - answer--DNA dependent RNApol
Transcribes DNA template to RNA (3'-->5'; anti-parallel)
Splicesomes - answer--Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
Enhancers - answer--Short regions of DNA that bind proteins (TXN
factors) that enhance TXN of a gene
QUESTIONS AND ALL CORRECT ANSWERS
100% SOLVED AND GUARANTEED SUCCESS!!
Pyrimidine - answer--One carbon ring
Cytosine, Thymine, Uracil
Purine - answer--Two carbon rings
Adenine, Guanine
How are nucleotides joined together? - answer--Condensation to form
phosphodiester bond
What is the function of mRNA? - answer--Carries genetic info out of
nucleus
Transcript translated to protein
What is the function of tRNA? - answer--Carries aa to ribosome
Anticodon pairs with codon on mRNA strand
,What is the function of rRNA? - answer--part of ribosome structure
most abundant RNA
coordinated coupling of tRNA to mRNA codons
Feedback inhibition - answer--Product of pathway is noncompetitive
inhibitor
Binds to allosteric site to slow down rxn b/c too much product
Exonucleases - answer--Degrades nucleic acids by removing one
terminal nt at a time
Cleaves phosphodiester bond at end of chain
5' --> 3' and 3' --> 5'
Endonucleases (Prok) - answer--Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
ORI sites - answer--nt sequence where replication is initiated
Topoisomerase I - answer--Induces ss breaks
,Remove DNA supercoils during TXN and DNA replication; for strand
breakage during recombination; for chr condensation; and to
disentangle intertwined DNA during mitosis
topoisomerase II - answer--cuts both strands of one DNA double helix,
passes another unbroken DNA helix through it, and then reanneals the
cut strands
Gyrase (topoisomerase II) - answer--Unwinds supercoiling caused by
unwinding at the rep fork by introducing DSBs
Helicase - answer--Breaks H-bonds of double helix at the replication fork
Primase - answer--DNApol α (DNA dep RNA pol)
adds short segments of complementary
RNA to ssDNA template (primers), serves as starting points for
replication
single-strand DNA binding proteins (SSBPs) - answer--Binds ssDNA and
prevents it from re-annealing during TXN, replication, repair, and
recombination
, Okazaki fragments - answer--Short fragments of DNA synthesized by
DNApol δ using the lagging strand (3'->5') as a template
Ligase - answer--Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
What are the steps in DNA replication? - answer--1. Initiate
2. Elongate
3. Terminate
Telomeres - answer--Repeat sequence (TTAGGG) at the ends of chr,
protect chr from degradation
RNA polymerase - answer--DNA dependent RNApol
Transcribes DNA template to RNA (3'-->5'; anti-parallel)
Splicesomes - answer--Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
Enhancers - answer--Short regions of DNA that bind proteins (TXN
factors) that enhance TXN of a gene
