Pyrimidine
ANSWER
One carbon ring
Cytosine, Thymine, Uracil
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
1
,coordinated coupling of tRNA to mRNA codons
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'
Feedback inhibition
ANSWER
Product of pathway is noncompetitive inhibitor
Binds to allosteric site to slow down rxn b/c too much product
ORI sites
ANSWER
nt sequence where replication is initiated
Endonucleases (Prok)
ANSWER
Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
Topoisomerase I
ANSWER
Induces ss breaks
2
,Remove DNA supercoils during TXN and DNA replication; for strand breakage during recom-
bination; 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 recombi-
nation
Okazaki fragments
3
, ANSWER
Short fragments of DNA synthesized by DNApol δ using the lagging strand (3'->5') as a tem-
plate
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
Splicesomes
ANSWER
Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
RNA polymerase
ANSWER
DNA dependent RNApol
4
ANSWER
One carbon ring
Cytosine, Thymine, Uracil
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
1
,coordinated coupling of tRNA to mRNA codons
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'
Feedback inhibition
ANSWER
Product of pathway is noncompetitive inhibitor
Binds to allosteric site to slow down rxn b/c too much product
ORI sites
ANSWER
nt sequence where replication is initiated
Endonucleases (Prok)
ANSWER
Restriction enzymes
Cleaves phoshpodiester bonds w/i poly-nt chain
Recognition site is palindromic sequence
Types I-V
Topoisomerase I
ANSWER
Induces ss breaks
2
,Remove DNA supercoils during TXN and DNA replication; for strand breakage during recom-
bination; 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 recombi-
nation
Okazaki fragments
3
, ANSWER
Short fragments of DNA synthesized by DNApol δ using the lagging strand (3'->5') as a tem-
plate
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
Splicesomes
ANSWER
Complex of snRNPs
Removes introns from pre-mRNA and splices exons together
RNA polymerase
ANSWER
DNA dependent RNApol
4
