CBG Lecture 33&34: Cell Architecture and Nuclear Transport Flashcards Preview

HELENP CBG: Cell Architecture, Communication and Regulation > CBG Lecture 33&34: Cell Architecture and Nuclear Transport > Flashcards

Flashcards in CBG Lecture 33&34: Cell Architecture and Nuclear Transport Deck (100)
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1

what are main organelles of eukaryotic cell

nucleus
SER/RER
Golgi apparatus (&golgins)
Peroxisomes
Lysosomes
Endosomes

2

outline the structure of the nucleus

nucleolus, nucleoplasm,nuclear lamina and innteer/outer nuclear envelope, perinuclear space with pores

3

what is the nucleae lamina

gives nucleus structure- filamentous proteins that form a meshwork on the inside of the inner nuc,ear membrane providing anchorage sites for chroms and nuclear pore

4

what happens to the nuclear lamina during mitosis

disassmebled and interacts with chromatin

5

what holds chromosomes in a non random arrangement

interaction of chroms with lamins holding chroms in fixed position in nucleoplasm

6

what controls the transort in and out of the nucleus

nuclear pore complex

7

what is the nucleus directly connected to

RER

8

what does concentration of NPCs of a nucleus depend on

increase nucleus activity, increase concentration NPCs

9

how many NPCs does a typical nucleus contain

3k-4k

10

what is role of the nucleus

half the cell mass
store DNA : euks-nucleus and endosymbionts, proks:nucleoid and plasmid
protection of genome from dynamic cytoskeleton and protection from condensation of genome during mitosis
regulate gene expression - TFs localise to nucleus
processing mRNA
bidirectional traffic
create ribosomes, mRNA and tRNA (nucleolus) ribosome constuction = rRNA and proteins - protein manufacturing in cytosol

11

how does nucleus protect the genome

from dynamic skeleton - causes condensation during mitosis

12

discuss the atomic-scale structure of the ribosome

LSU - 49proteins &2RNA
SSU = 33 proteins&1RNA molecule

13

what is the nuclear lamina

meshwork of interocnnected proteins called lamins that give shape and stability
interacts with proteins on inner nuclesar membrane
interacts with chromatin
disassembled during mitosis

14

what is an NPC

nuclear pore complex
v big macromolecule 125MDa - composed of 30 different nuclearporin proteins

15

what is structure of NPC

3 main parts
1.cytoplasmic fibrils
2.central framework
3.nuclear basket

16

what is inside the central framework of the NPC

an FG (phenol&glycine rich) meshwork core: transport conduit - permeability barrier

17

what was used to determine architecture of NPC

crosslinking of neighbouring proteins)
mass spec/proteomics
Immuno EM
analytical ultracentrifugation

18

how to separate RER from SER

by centrifugation

19

what is the ER

a network of interconnected branching tubules extending throughout the cytosol

20

how much of total cell volume does ER cisternal space occupy

Er lumen occupies >>10%

21

what is ERs major contribution to cell

Er membrane makes major contribution to mitochondrial and peroxisomal membranes by producing most of their lipids

22

where are almost all of the proteins that will be secreted to the cell exterior and those destined for lumen of Golgi/lyossomes initially secreted to

ER - ER captires selected proteins from the cytosol as they're being syntheszed

23

what makes RER different from SER

has membrane bound ribosomes that coat the surface

24

what type of ER do hepatocytes have

SER

25

what are SERs involved in

lipid and carb metabolism

26

what do SERs sequester

Ca2+ from cytosol - important for muscle cell contraction

27

what is a Golgi Apparatus

organised ordered stacks of disklike compartments called cisternae which receive lipid proteins from ER and dispatches them

28

why does Golgi have directionality

cis-trans faces for vesicle transportation

29

what does the structural integrity of Golgi depend on

microtubules and cytoskeleton

30

what helps organise the Golgi stack of cisternae

the Golgi matrix