Gene expression in eukaryotes

HideShow resource information
What are unicellular eukaryotes sometimes called?
Protists and protozoans
1 of 34
What is the genome structure of a eukaryotic cell?
nuclear membrane, linear chromosomes, condensed chromatin by histones, multiple replication origins, singe gene transcription
2 of 34
Which organism can contain operon like structures?
C. elegans
3 of 34
Do eukaryotes have linear or circular chromosomes?
linear
4 of 34
Do eukaryotic cells have multiple replication origins?
yes
5 of 34
Do eukaryotes have multiple gene transcription?
no
6 of 34
What are similarities between eukaryotic and prokaryotic expression regulation?
RNA polymerases allow transcription, mRNA transcript translated into protein by ribosomes, genetic code is nearly universal
7 of 34
What are the three types of RNA polymerase?
polymerase I, polymerase II, polymerase III
8 of 34
what does polymerase I transcribe?
rRNAs
9 of 34
What does polymerase II transcribe?
pre mRNAs, snoRNAs, some miRNAs and snRNAs
10 of 34
What soes polymerase III transcribe?
tRNAs, small RNAs, miRNAs, some snRNAs
11 of 34
How many additional polymerases have been found in plants?
two
12 of 34
What must happen to eukaryotic DNA before transcription?
DNA must unwind from histone proteins
13 of 34
Where does protein synthesis take place?
transcription in nucleus, mRNAs then transported into cytoplasm - on ribosomes, for translation
14 of 34
How many genes does one promoter control?
one gene
15 of 34
What do basal transcription factors do?
they respond from injunctions from activators. They position RNA polymerase at the start of transcription and initiate the transcription process
16 of 34
What is the role of repressors?
they bind to selected sets of genes at sites known as silencers, and slow transcription
17 of 34
What do activators do?
these proteins bind to genes at sites called enhances and speed up rate of transcription
18 of 34
What do coactivators do?
these adapter molecules integrate signals from activators and perhaps repressors
19 of 34
Why is it that not all genes are active at any given time?
Because it requires energy for a gene to be transcribed and translated, turning genes that aren't required off conserves energy
20 of 34
What does increasing the amount of activator binding sites do?
it can increase the efficiency of recruiting the transcription machinery, such as activators and basal transcription factors
21 of 34
What is the base sequence of the beginning of the core promoter?
TATA
22 of 34
Can different sequences be mixed and matched in different combinations?
yes, a different transcriptional activator protein binds to each consensus sequence, so each promoter responds to a unique combination of activator proteins
23 of 34
What is an insulator?
a DNA sequence that blocks or insulates the effect of enhancers, they often lie between the enhancer and the promoter
24 of 34
What is transcriptional stalling?
when the progress of the RNA polymerase is stalled after the initiation of transcription, then when the right cue is present transcription elongation blocks are released so transcription can proceed
25 of 34
What does transcriptional stalling allow?
faster transcription of genes when needed
26 of 34
What specific proteins is transcriptional stalling used for?
heat-shock proteins and sometimes other genes
27 of 34
How can chromatin structure be altered?
chromatin remodelling complexes, histone modifications, DNA methylation
28 of 34
What type of histone modifications
methylation and acetylation
29 of 34
Can changes in chromatin structure affect gene expression?
yes
30 of 34
Why does chromatin structure vary over time?
to allow transcription of RNAs
31 of 34
How is chromatin remodelled?
changes in chromatin structure by repositioning nucleosomes, thus exposing binding sites on DNA (18.2 on textbook)
32 of 34
What does chromatin remodellin allow?
transcription factors to bind to DNA and initiate transcription
33 of 34
How is chromatin remodelling mediated?
by chromatin remodelling complexes binding to specific DNA sites, the complexes include transcription factors and regulatory proteins
34 of 34

Other cards in this set

Card 2

Front

What is the genome structure of a eukaryotic cell?

Back

nuclear membrane, linear chromosomes, condensed chromatin by histones, multiple replication origins, singe gene transcription

Card 3

Front

Which organism can contain operon like structures?

Back

Preview of the front of card 3

Card 4

Front

Do eukaryotes have linear or circular chromosomes?

Back

Preview of the front of card 4

Card 5

Front

Do eukaryotic cells have multiple replication origins?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Gene expression resources »