chapter 13 Flashcards
which statement about RNA is not true?
RNA is more stable molecule than DNA
which class of RNA serves as the coding instruction read by the ribosome to produce a polypeptide chain?
mRNA
which region would not be present in the final RNA transcript ?
promoter
which of the subunits does not permanently associate with the enzyme core?
sigma
frequently, important DNA regions with specific functions tend to contain short stretches of nucleotides that are conserved across different organisms (promoter sequence) are recognized by specific proteins.
what are these conserved sequences called?
consensus sequence
during the rho-independent termination of transcription in some bacteria, the formation of ____ is critical.
a hairpin loop via inverted repeats
complete the transcription of the RNA sequence using the DNA template
DNA template:
ATCGAC
RNA sequence:
UAGCUG
identify the statements that are features of a promoter
in prokaryotes, the promoter contains a -35 and -10 region upstream of the transcription start site
in both prokaryotes and eukaryotes, the promoter is located in the 5’ direction, upstream from the transcription start site
in eukaryotes, the promoter often contains a TATA box, which is where the TATA- binding protein binds
which of the following statements describes the function of the sigma factor in prokaryotic transcription?
it facilitates the binding of RNA polymerase to the promoter to initiate transcription
which of the two DNA strands as the template for transcription?
either DNA strand may be used as a template by RNA polymerase, but a single DNA strand oriented in the 3’-5’ direction is used as a template each time transcription occurs
the diagram represents DNA that is part of the RNA coding sequence a transcription unit. The bottom strand is the template strand.
5’-GCATATGCGGTAC-3’
3’- CGTATACGCCATG-5’
give the sequence found on the RNA molecule that is transcribed from the above DNA molecule.
5’- GCAUAUGCGGUAC-3’
what’s the role of the eukaryotic promoter in transcription?
the site where RNA polymerase binds to initiate transcription
classify each description to the appropriate category
transcription: acts on only one strand & catalyzed by RNA polymerase
replication: catalyzed by DNA polymerase & RNA primase is required
both: localized in the cytoplasm in prokaryotic cells
RNA polymerase carry out transcription at much lower rates than DNA polymerases carry out replication.
why is greater efficiency more important in replication than in transcription?
the product of replication is larger than the product of transcription by orders of magnitude, and DNA polymerases are faster to compensate
what happens during the initiation step of DNA replication?
a portion of the DNA unwinds and RNA polymerase attaches to the DNA within the transcription bubble
