Unit 1 Flashcards
1
Q
Nuclear Envelope
A
1.) Inner & Outer nuclear membranes
2.) Nuclear Lamina; Fibrous network
3.) Nuclear pore complexes; channels through which molecules can travel between nucleus & cytoplasm
2
Q
Lamins
A
- Compose nuclear lamina
- Phosphorylation / dephosphorylation of lamins controls integrity of nuclear lamina
3
Q
Emerin
A
- Lamin-binding protein
4
Q
GEF
A
- Guanine nucleotide exchange factor
- Needed for binding of GTP
5
Q
GAP
A
- GTPase activating protein
- Needed for hydrolysis of GTP to GDP (inactivation)
6
Q
NLS
A
- Nuclear localisation signal
- Found in certain proteins, lets them bind to an NLS receptor
7
Q
Importin α / β
A
1.) Bind to proteins w/ NLS
2.) Associates w/ cytoplasmic filaments
3.) Passes through NPC
8
Q
Ran
A
- GTPase
- Binds to protein-importin complex
- Forms Ran*GTP-importin β complex
- Transported back to cytoplasm where Ran*GTP is converted to Ran GDP, & is brought back to nucleus
9
Q
Exportin
A
- Transports importin α back to cytoplasm
10
Q
Chromatin
A
- Complexes of eukaryotic DNA & proteins
- Contains ~2x as much protein as DNA
- Major proteins of chromatin are histones
11
Q
Histones
A
- Small proteins containing high proportion of basic amino acids
12
Q
Cohesin
A
- Stabilize supercoiled loops of higher-ordered structures of chromatin
13
Q
Euchromatin
A
- Return to a dispersed state after mitosis
14
Q
Heterochromatin
A
- Condensed during interphase
- Constituative Heterochromatin
a.) Always condensed
b.) Mostly found around centromeres & telomeres
c.) Consists of highly repeated sequences & few games - Facultative Heterochromatin
a.) Inactivated during certain phases of the organism’s life (X-inactivation)
15
Q
Flavoproteins
A
- Contain NAD+, FAD+ prosthetic groups
- Compose complexes 1/2 in ETC
- Pass e- to Ubiquinone
