chapter 7 Flashcards
(27 cards)
DNA topoisomers
relaxes super coiling
Helicase (DNAB)
unwinds the double helix
SSB
prevents the reannealing of separated strands
primase
synthesizes RNA primers
DNA polymerase III
synthesizes DNA
DNA polymerase I
removes and replaces RNA primers with DNA
DNA ligase
joins DNA (okazaki) segments
3 steps of the polymerase chain reaction
denaturation
annealing
extension
is produced by protein-encoding genes and is a short-lived intermediary between DNA and protein
the only type of RNA that undergoes translation
messenger RNA (mRNA)
do not encode proteins but instead perform functional roles in the cell
functional RNAs (fRNA)
encoded in dozens of forms, responsible for binding an amino acid and depositing it for inclusion into a growing protein chain
transfer RNA
combines with numerous proteins to form ribosomes
ribosomal RNA (rRNA)
promoter
site where RNA polymerase attaches to template
cap
5’ end
poly(A) tail
3’ end
splicing
removes introns and joins exons
introns
non-coding sequences that interrupt coding sequence (intervening sequence)
exons
sequences that remain in the final mature mRNA
transcription and RNA processing are coupled in prokaryotes or eukaryotes
eukaryotes
main components of translation
- mRNA
- transfer RNA
- ribosomes
what are the ingredients necessary for a PCR reaction??
dNTPs , primers, template DNA, heat stable taq polymerase
where does RNA polymerase add nucleotides and do they need a primer
3’-OH end and no
translation
RNA directed synthesis of a polypeptide
in ____ , the 5’ end of a pre-mRNA is modified by the addition of a ____
eukaryotes, 5’cap