Lecture 1/19 - Central Dogma Flashcards
Does DNA polymerase require a primer
Yes it requires an RNA primer. It can’t get started de novo
Joining of Okazaki fragments
ligase
Requirements for DNA transcription
RNAP, template DNA, UTP, ATP, GTP, CTP and Mg++ or Mn++ ion
How many different tRNAs
61 (3/64 are stop codons)
CAP (catabolic activator protein)
CRP (c-AMP Response Protein)
Name the site where RNA Polymerase II (RNAPII) would bind in order to transcribe this gene
into mRNA
Promoter region
Name the two possible sites where the transcription factor, SREBP, might bind
promotor or enhancer region
What must be loosened or moved out of the way for effective RNAPII binding?
Histones
When cholesterol levels drop, the SREBP moves to the Golgi. Describe what happens that
enables SREBP to activate transcription
Protease clips SREBP to free it from transmembrane domain and it diffuses to nucleus to find its target DNA element
The 45 S pre-rRNA of eukaryotes
a.
Is transcribed by RNA Polymerase I from DNA in the nucleolus region of the nucleus
b. FALSE (not translated) Is processed into 28 S, 18 S, and 5.8 S rRNA pieces that are translated into proteins by
existing ribosomes in the cytoplasm
c.
Provides part of ribosomal structure after it is processed and combined with ribosomal
proteins
d. Is the source of the enzymatic activity for peptidyl transferase present in ribosomes
The synthesis of mRNA in eukaryotes requires…
a.
RNA polymerase II
b. General (basal) transcription factors such as TFIID, TFIIB
c.
DOES NOT need An RNA primer
d. A free 3’ hydroxyl group to which the incoming nucleotide will be attached
Histone acetylases
a.
Loosen the binding of histones to DNA by adding acetyl groups to histones
b. Are recruited by coactivators that may be bound to transcription factors
c. FALSE
Repress transcription until the acetyl group is removed by Histone deacetylases
d. FALSE Are enzymes that are part of the histone H2a, H2b, H3, and H4 structures
Single strand binding proteins
Keep the strands apart
DNA polymerase adds to which end
3’
Which ways does replication proceed in the transcription bubble
Both ways
Topoisomerase (gyrase)
Responsible for straightening out the helixes (unwinds)
Single strand binding proteins
Keep the strands apart
DNA polymerase adds to which end?
3’
Which ways does replication proceed in the transcription bubble?
Both ways
Helicase
The enzyme responsible for separating DNA strands
How many DNA polymerase III’s are in replication bubble
2
Removal of okazaki RNA primers
RNase H and DNA polymerase I
Differences between DNA and RNA polymerase
- RNA polymerase only copies template strand (anti-sense strand)
- Doesn’t require primer
- Doesn’t have editing function
- w/ sigma - holoenzyme; w/o sigma - core enzyme
Function of A site in ribosome
Where we bring in a new amino acid
