the nucleus Flashcards
1
Q
what does the nucleus contain?
A
- chromatin
- double membrane
- envelope
- inner membrane
- outer membrane
- meshwork of intermediate filaments
- nucleolus
- nucleoskeleton
- organisation
- perinuclear space
- pores
- structure
2
Q
functions of the nucleus
A
- gene transcription + translation
- ribosome assembly
- mRNA production
- mRNA splicing
- rRNA cleavage
- rRNA production
- tRNA production
3
Q
how many protein subunits does the nuclear pore contain
A
several hundred
4
Q
how many pores does the nucleus contain
A
several thousand
5
Q
how does transport throught the nuclear pore occur
A
gated and in both directions
6
Q
how do large molecules move through the pore?
A
> 60 kDa
need import and export signals
7
Q
how do molecules between 5-60 kDa move through a pore?
A
slowly
8
Q
how do small molecules move through the nuclear pore?
A
< 5 kDa
diffuse rapidly
9
Q
how many copies of gene encoding rRNA do cells contain?
A
around 200
10
Q
where is rRNA produced from?
A
rDNA
11
Q
how much of the total RNA in a cell does rRNA make up?
A
80%
12
Q
Roughly, how many ribosomes per cell?
A
10,000,000
