Basic Membrane Trafficking

?
what is the first type of protein that is synthesised in the RER?
Transmembrane proteins
1 of 52
what is the second type of protein that is synthesised in the RER?
Proteins destined for exocytosis
2 of 52
When is RER 'rough'?
When ribosomes attach for protein translation
3 of 52
what is the process of transporting proteins to the RER called?
co-translational translocation
4 of 52
Why doesn't a protein fold up in co-translational tranlocation?
One end of the protein is attached to Ribosome the other is attached to ER
5 of 52
What must a protein have that is destined to the RER?
Signal sequence
6 of 52
where is the signal sequence located on protein destined to RER?
N-terminus
7 of 52
what is the signal sequence recognised by?
Signal Recognition Particle
8 of 52
What does the SRP bind too?
The signal sequence of synthesised protein and ribosome
9 of 52
what happens when the Signal recognition particle binds?
Translation is paused/stoped
10 of 52
what is a SRP composed of?
RNA and 6 Proteins
11 of 52
what recognises the SRP on the RER?
SRP receptor (Signal recognition particle receptor)
12 of 52
What does the SRP Receptor do?
Guides the ribosome to the Protein Translocator and translation continues.
13 of 52
Multiple ribosomes may translate one mRNA strand, what are these called?
Polyribosomes or Polysomes
14 of 52
What happens to mRNA after translation
mRNA is degraded in the cytoplasm
15 of 52
If a protein is destined to be released from the cell, where will it be sent too in the ER?
The lumen
16 of 52
If a protein is destined to be membrane bound, where will it be sent too in the ER
Embedded in the ER membrane
17 of 52
What modification takes place on the protein in the RER?
Glycosylation
18 of 52
What is added during Glycosylation and where on the protein?
14 sugar oligosaccharide attached to the asparagine side chain(N-terminus)
19 of 52
what is the name given to a protein when it has been glycosylated
Glycoprotein
20 of 52
After folding of protein what is cleaved from the Glycoprotein
3 x glucose and 1 x Mannose sugars
21 of 52
If the protein is folded incorrectly what is added back
1 x glucose molecule
22 of 52
What enzyme is responsible for the adding back of a glucose molecule
glucosyl Transferase
23 of 52
What does a incorrectly folded protein bind too?
Chaperone
24 of 52
Give a example of a chaperone
Calnexin
25 of 52
what is triggered when there is a accumulation of incorrectly folded proteins?
Unfolded Protein Response
26 of 52
What does a unfolded protein response involved?
1. Inhibit protein synthesis 2. Increase transcription of chaperones 3. Degraded of misfolded proteins
27 of 52
If proteins continue to be missfolded what happens
Apoptosis (Program cell death)
28 of 52
When are COPI Coated vesicles used
Transport of cargo from the Golgi
29 of 52
when are COPII coated vesicles used
Transport of proteins from the RER
30 of 52
when are CLATHRIN coated vesicles used
Transport of cargo from the cell membrane and golgi to endosomes/lysosomes
31 of 52
What are the three pathways of membrane trafficking
Secretory, endocytic and retrieval
32 of 52
What molecule is responsible for membrane specificity
Rab-GTP
33 of 52
What protein activated Rab-GDP
GEF(Guanosine Exchange Factor)
34 of 52
What recognises Rab-GTP on target membrane
Rab-GTP effector protein
35 of 52
what deactivates/Hydrolyses Rab-GTP
Rab-GAP (GTPase activating protein)
36 of 52
what is released with Rab-GDP to prevent reactivation
Rab-GTP dissociation inhibitor
37 of 52
What proteins are responsible for membrane fusion?
V-snares and T-snares
38 of 52
What is produced when multiple vesicles fuse together?
Vesticular tubular clusters
39 of 52
How are Vesticular tubular clusters transported?
via microtubules
40 of 52
What is the GOLGI responsible for?
Processing of proteins/ensuring correctly folded and to sort cargo to correct pathway
41 of 52
what do lysosomes do?
Degraded/breakdown unwanted materials using enzymes
42 of 52
what is the usual pH of a lysosome
4.5 - 5pH
43 of 52
What must cargo destined to lysosomes from golgi have?
Clathrin coated vesicle with Mannose-6-phosphate tag
44 of 52
How are lysosomes formed?
Late endosomes bind to lysosome to form endolysosome which digests material then become lysosome
45 of 52
how is a mannose-6-phosphate added to protein
Glucose molecule is added which is then phosphorylated
46 of 52
what is formed from cargo/material entering the cell?
Early endosome
47 of 52
if endocytosed material is destined to be recycled what does it form?
Recycling endosome
48 of 52
If material is destined to be broken down what happens to the early endosome
becomes a late endosome and forms a lysosome
49 of 52
what are the TWO methods on exocytosis?
Constitutive secretory pathway & Regulated secretory pathway
50 of 52
what is the constitutive secretory pathway?
unregulated membrane fusion (no timing)
51 of 52
what is regulated secretory pathway?
requires a signal for release, stored in vesicles close to the cell membrane
52 of 52

Other cards in this set

Card 2

Front

what is the second type of protein that is synthesised in the RER?

Back

Proteins destined for exocytosis

Card 3

Front

When is RER 'rough'?

Back

Preview of the front of card 3

Card 4

Front

what is the process of transporting proteins to the RER called?

Back

Preview of the front of card 4

Card 5

Front

Why doesn't a protein fold up in co-translational tranlocation?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Human Biology resources:

See all Human Biology resources »See all Biochemistry resources »