Exam 3- Vesicular Transport

Question 1

what are the 2 directions that vesicular traffic can go

Answer 1

antero and retro

Question 2

Anterograde

Answer 2

out of cell

toward PM

Question 3

retrograde

Answer 3

into cell

toward ER

Question 4

parent compartment

Answer 4

where the buds arise from

Question 5

Target compartment

Answer 5

where the buds are directed to

Question 6

what is vesicular transport

Answer 6

transport of cellular material through the cell within membrane-bound vesicles. This occurs by the budding off of vesicles (with packaged material within) from one compartment and then fusion of the vesicle with the membrane of another compartment

Question 7

What is cargo

Answer 7

the proteins carried in the vesicles for transport

Question 8

what are coat proteins

Answer 8

Cytosolic proteins that drive the process of budding, coat membrane causing a deformity, ultimately forming a bud. Have the ability to form trimers that adopt a triskelion shape or SOCCER BALL

Question 9

What triggers budding?

Answer 9

Polymerization of the COAT proteins is the event that drives budding (vesicle formation) in the secretory pathway.

Question 10

What are the coats used at different stages during the secretory pathway?

Answer 10

COP-I – retrograde, Golgi to ER

COP-II – anterograde, ER to Golgi

Clathrin- from Golgi to PM, in both directions

Question 11

What type of proteins select the coat to be used?

Answer 11

The adaptor proteins. KKXX- recognized by the adaptor, recruits COP-I for retrograde direction

Question 12

What are the v-SNARES

Answer 12

vesicles from ER have vSNARE that bind specific tSNARE on the golgi

Question 13

What are the t-SNARES

Answer 13

target compartment, have V-SNARE that it can interact with.

Question 14

what happens when v and t SNARES interact

Answer 14

once these proteins embrace, mediation of membrane fusion occurs. Changes the conformation of snares and results in membrane fusion.

Question 15

Why is the cytoskeleton relevant for vesicular transport? What’s the role of Kinesin?

Answer 15

the cytoskeleton microtubules create tracks that the vesicles can move along.
Kinesin is for anterograde
Dynein is for retrograde

Question 16

what is endocytosis?

Answer 16

Bringing contents into the cell

Question 17

What is exocytosis?

Answer 17

secrete out of the cell

Question 18

Where (in which compartment) are membrane receptors recycled?

Answer 18

the lysosome

Question 19

Where do the secretory and endocytotic pathways meet?

Answer 19

endosome

Question 20

-What types of enzymes are present in Lysozomes? What property do they have in common?

Answer 20

Nucleases, proteases, glycosidases, lipases, phosphatases, sulfatases, phosphlipases. Which can degrade every macromolecule in the cell.

Question 21

What’s the pH of the Lysozome? How is that important?

Answer 21

pH is approximately 5.0, which is important because these enzymes can only work at a low pH through the use of an H pump.