Endomembrane System

Question 1

what is the vesicle receptor proteins function

Answer 1

to regulate intracellular trafficking to the proper recipient membrane, regulate vesicle recipient membrane fusion

Question 2

4 basic steps of vesicle transport

Answer 2

1. budding off = vesicle buds off the donor membrane compartment
2. transported = nascent vesicle is transported through the cytosol to the recipient membrane compartment
3. fusing = vesicle fuses with proper membrane compartment
4. repeat or reverse

Question 3

what does it mean by motor proteins

Answer 3

when it involves molecular motors and cytoskeleton highways to direct vesicle movement within the cell

Question 4

Where does the biosynthetic pathway take place

Answer 4

materials are transported from the golgi to the PM or released out

Question 5

Describe the secretory pathway for constitutive secretion

Answer 5

ER derived materials are transported from the Golgi to the PM or released out. The transport vesicle membrane components are incorporated into he PM to release luminal cargo into the extracellular space

Question 6

Explain regulated secretion

Answer 6

occurs in specialized cells only
the ER derived materials from the Golgi are stored in secretory granules to be stimulated by a cellular signal, the secretory granules then fuse with the PM and release their lumenal cargo into the extracellular space

Question 7

explain the endocytic pathway

Answer 7

operates in the opposite direction of the secretory pathway so materials from the PM receptor proteins are incorporated into the cell and then transported to endosome and lysosomes

Question 8

What is the lumen in the endoplasmic reticulum

Answer 8

an aqueous space inside the ER tubules and cisternae

Question 9

how are cisternae and tubules mediated

Answer 9

the shapes are mediated by reticulons in constant flux (hairpin V shaped secondary structures and regulate the ER membrane curvature)

Question 10

is the rough ER mostly made of cisternae or tubules

Answer 10

cisternae with bound ribosomes

Question 11

what is the rough ER for

Answer 11

membrane and phospholipid synthesis

Question 12

is the smooth ER made of cisternae or tubules

Answer 12

mostly curved tubules lacking ribosomes

Question 13

what is the smooth ER function

Answer 13

involved in CA2+ storage and hormone synthesis

Question 14

What are ER exit sites (ERES)

Answer 14

regions where transport vesicles bud off from the ER on their way to the Golgi

Question 15

what is the outer nuclear membranes structure and function

Answer 15

Structure = continuous with the RER and contains NUPs and attached ribosomes
Function = they make direct contact with the mitochondria or PM and are involved in membrane lipid exchange