ASCP TECHNOLOGIST IN MOLECULAR
BIOLOGY
BOARD EXAM PREP EXAM COMPLETE
SOLUTION GRADED A+
ASCP Technologist in Molecular Biology board exam prep
Technologist in Molecular Biology, MB(ASCP) board exam prep
• Pyrimidine
• One carbon ring
• Cytosine, Thymine, Uracil
Purine
• Two carbon rings
• Adenine, Guanine
How are nucleotides joined together?
• Condensation to form phosphodiester bond
What is the function of mRNA?
• Carries genetic info out of nucleus
• Transcript translated to protein
,What is the function of tRNA?
• Carries aa to ribosome
• Anticodon pairs with codon on mRNA strand
What is the function of rRNA?
• part of ribosome structure
• most abundant RNA
• coordinated coupling of tRNA to mRNA codons
Feedback inhibition
• Product of pathway is noncompetitive inhibitor
• Binds to allosteric site to slow down rxn b/c too much product
Exonucleases
• 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)
• Restriction enzymes
• Cleaves phoshpodiester bonds w/i poly-nt chain
• Recognition site is palindromic sequence
• Types I-V
ORI sites nt sequence where replication is
initiated
Topoisomerase I
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
cuts both strands of one DNA double helix, passes another unbroken DNA helix through it, and then
reanneals the cut strands
Gyrase (topoisomerase II)
Unwinds supercoiling caused by unwinding at the rep fork by introducing DSBs
, Helicase
Breaks H-bonds of double helix at the replication fork
Primase
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)
Binds ssDNA and prevents it from re-annealing during TXN, replication, repair, and recombination
Okazaki fragments
Short fragments of DNA synthesized by DNApol δ using the lagging strand (3'->5') as a template
Ligase
Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
BIOLOGY
BOARD EXAM PREP EXAM COMPLETE
SOLUTION GRADED A+
ASCP Technologist in Molecular Biology board exam prep
Technologist in Molecular Biology, MB(ASCP) board exam prep
• Pyrimidine
• One carbon ring
• Cytosine, Thymine, Uracil
Purine
• Two carbon rings
• Adenine, Guanine
How are nucleotides joined together?
• Condensation to form phosphodiester bond
What is the function of mRNA?
• Carries genetic info out of nucleus
• Transcript translated to protein
,What is the function of tRNA?
• Carries aa to ribosome
• Anticodon pairs with codon on mRNA strand
What is the function of rRNA?
• part of ribosome structure
• most abundant RNA
• coordinated coupling of tRNA to mRNA codons
Feedback inhibition
• Product of pathway is noncompetitive inhibitor
• Binds to allosteric site to slow down rxn b/c too much product
Exonucleases
• 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)
• Restriction enzymes
• Cleaves phoshpodiester bonds w/i poly-nt chain
• Recognition site is palindromic sequence
• Types I-V
ORI sites nt sequence where replication is
initiated
Topoisomerase I
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
cuts both strands of one DNA double helix, passes another unbroken DNA helix through it, and then
reanneals the cut strands
Gyrase (topoisomerase II)
Unwinds supercoiling caused by unwinding at the rep fork by introducing DSBs
, Helicase
Breaks H-bonds of double helix at the replication fork
Primase
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)
Binds ssDNA and prevents it from re-annealing during TXN, replication, repair, and recombination
Okazaki fragments
Short fragments of DNA synthesized by DNApol δ using the lagging strand (3'->5') as a template
Ligase
Closes gaps in DNA
Catalyzes phosphodiester bond between 3'OH and 5'P
