Histology - Nucleus Flashcards
0
Q
Nucleolus
A
The center of ribosomal (rRNA) synthesis
1
Q
Peptidyl transferase
A
In a rRNA-based enzyme of the large subunit
2
Q
Chromatin
A
The genetic material of the cell
3
Q
Nucleoplasm
A
Containing macromolecules and nuclear particles involved in the maintainance of the cell
4
Q
Nuclear envelope
A
- Inner and outer nuclear membranes
- Perinuclear cisterna
- Nuclear pores
5
Q
Inner nuclear membrane
A
- In contact with the nuclear lamina
- > Composed of lamins A, B, and C
- > Located at the periphery of nucleoplasm
- > Support the lipid bilayer membrane and the perinuclear chromatin
- Integral proteins on the inner nuclear membrane
6
Q
Outer nuclear membrane
A
- Continuous woth RER
- Surrounded with vimentin
- > Vimentin is a loose network of intermediate filament
- Usually possess ribosomes that actively synthesize transmembrane proteins that are destined for the outer or inner membrane
7
Q
Nuclear pore complex
A
Glycoproteins (nonmembranous structures) + nuclear pore = nuclear pore complex
8
Q
Nonmembranous structures
A
Glycoproteins
9
Q
Nuclear pore function
A
- Simple diffusion of ions and small molecules
- “Receptor-mediated transport” for macromolecules and particles larger than 11nm
- Importins -> NLSs
- Exportins -> NESs
Both exportins and imprtins are RAN-regulated - Nucleoplasmic shuttling (NS)
-> Proteins that carry this signal interact with mRNA
10
Q
Nuclear lamina
A
- IS IN THE INNER NUCLEAR MEMBRANE
- Interwoven meshwork of intermediate filaments
- Composed of: Lamins A, B, and C
- Location: The periphery of the cytoplasm
11
Q
nonmembranous structures
A
E.g glycoproteins
12
Q
Cytoplasmic ring is composed of…..
A
- 8 subunits –> located on the rim of the cytoplasmic aspect of the nuclear pore
13
Q
Importins
A
Nuclear localization signals (NLSs)
14
Q
Exportins
A
Nuclear export signals (NESs)
