Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cell Bio > 2-protein trafficking > Flashcards

2-protein trafficking Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Eukaryotic cells are highly organized with ____________

A

specialized sub-compartments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

different organelles have _______

A

distinct ionic and pH compositions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

cellular anatomy is _______

A

highly dynamic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

protein traffic is required to _________

A

establish and maintain compartmental identity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

where are proteins produced

A

ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

proteins contain:

A

recognition motifs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

examples of diverse recognition motifs:

A
  1. signal sequence
  2. signal patch
  3. post translational modification
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

recognition motifs are recognized by _____ which ______

A

machinery
facilitates transport to the appropriate organelle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the default pathway

A

cytosol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

3 major mechanisms for protein targeting to organelles

A
  1. gated transport
  2. transmembrane transport
  3. vesicular transport
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

in nuclear/gated transport, what gets imported into the nucleus?

A

-all histones needed to make nucleosomes
-all ribosomal proteins needed for the association of rRNA
-all gene transcription factors
-all splicing factors needed to process pre-mRNA into mature mRNA molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

in nuclear/gated transport, what gets exported from the nucleus?

A

-all ribosomal subunits containing both rRNA and proteins
-mRNA molecules
-tRNA molecules
-transcription factors that are returned to the cytosol to await reuse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is gated transport?

A

-protein traffic between cytosol and nucleus through nuclear pore complexes.
-pore complexes function as selective gates that actively transport selected macromolecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is transmembrane transport?

A

-protein translocators directly transport proteins across a membrane from the cytosol into a space that is distinct.
-Transported in unfolded state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is vesicular transport?

A

-membrane enclosed transport vesicles transport proteins from one compartment to another.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

signals for nuclear/gated transport?

A

-nuclear localization signals (NLS)
-nuclear export signals (NES)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are nuclear export signals (NES)

A

import proteins out of the nucleus via exportins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

are nuclear localization signals cleaved after usage?

A

no, they remain in the cell in case the cell divides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how is nuclear transport regulated?

A

transcriptional control

20
Q

what are nuclear localization signals (NLS)

A

import proteins into nucleus via importins

21
Q

how do nuclear import/export signals work?

A

-NLS/NES signals are recognized by import/export receptors, proteins that act as taxis.
-Import/export receptors may interact with the cargo directly or indirectly.

22
Q

many compartments are bounded by membranes composed of _______

A

lipid bilayers

23
Q

in transmembrane protein transport, transport to organelles like ER/mitochondria crosses

A

lipid bilayer barriers

24
Q

basic concept or vesicular transport

A

-all vesicle transfer processes involves budding and fusion
-cargo is contained within a transport vesicle
-fusion is regulated and specific

25
Q

2 pathways of vesicular transport

A

-exocytic pathway
-endocytic pathway

26
Q

example of exocytic pathway

A

site of protein synthesis in ER through Golgi to the plasma membrane

27
Q

example of endocytic pathway

A

from plasma membrane through endosomes to lysosomes

28
Q

what do transport vesicles do?

A

-carry material between compartments of the exocytic and endocytic pathway

29
Q

all newly synthesized proteins destined for secretion from the cell or for organelles in the exocytic/endocytic pathways share a common entry point______

A

at the ER membrane

30
Q

the signal for protein translocation across the ER membrane is

A

signal sequence

31
Q

as translation occurs, the signal sequence is recognized by ___

A

SRP (signal recognition particle)

32
Q

how do proteins enter ER?

A
  • SRP recognized signal sequence in cytosol and binds to it
    -brings the ribosome and nascent protein to the surface of ER membrane
    -translocator imports the protein as it is synthesized across the ER membrane
    -signal sequence is removed after translocation via signal peptidase
33
Q

what happens to proteins in the ER

A

bind to core N-linked glycosylation that work as chaperones to facilitate correct protein binding

34
Q

how is protein trafficking regulated

A

only correctly folded proteins are allowed to enter transport vesicles

35
Q

what happens to proteins after it enters the ER?

A

-proteins are transported in vesicles to the Golgi
-further processes and sorted for transport
-endocytic vesicles are derived from plasma membrane
-endocytic vesicles traffic to endosomes where proteins can be recycled or transported

36
Q

what are the different golgi processing fates?

A

-N linked oligosaccharides on proteins destined for plasma membrane are modified to terminate with sialic acid residues
-Diff post translational modifications create signals for diverse destinations
-N linked oligosaccharides destined for lysosome are modified by becoming phosphorylated on a mannose residue

37
Q

a donor of vesicular transport

A

buds membrane bound transport vesicles that carry cargo

38
Q

an acceptor of vesicular transport

A

receives cargo by fusion of incoming membrane-bound transport vesicles carrying cargo

39
Q

what is M6P signal?

A

every protein that enters the lysosome must be tagged with M6P to enter

40
Q

M6P groups are recognized by what?

A

transmembrane M6P receptor proteins which are present in Golgi

41
Q

how does the protein go from the golgi to the lysosome?

A
  1. M6P groups are recognized by transmembrane M6P receptor proteins
  2. Receptor proteins bind to lysosomal hydrolases which help pack the hydrolases into clathrin coated vesicles that bud from golgi
  3. vesicles deliver contents to a late endosome and onto lysosome
42
Q

in late endosomes, lysosomal hydrolases ______ from the M6P receptor

A

dissociate

43
Q

M6P receptor protein binds M6P tag at the pH of the golgi network and releases it _____

A

at a slightly more acidic luminal pH of late endosomes

44
Q

what is endocytosis

A

intracellular vesicle-mediated transport route that originates at the plasma membrane

45
Q

what does endocytosis enable the cell to do?

A

-acquire nutrients including macromolecules, internalize receptors, and maintain cell surfaces

46
Q

what are possible fates for transmembrane receptor proteins that have been endocytosed?

A
  1. returned to same plasma membrane (recycling)
  2. to a diff domain of the plasma membrane (transcytosis)
  3. follow the pathway to lysosomes (degredation)

Cell Bio (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions