DLA 2-Vesicular transport

Question 1

ENdocytosis

Definition and 2 things to note

Answer 1

Vesicular transport in which cells eNter
1. Controls composition of plasma membrane and celullar responses to changes in external environment
2. Nutrient uptake, cell signaling and shape changes

Question 2

EXocytosis definition

Answer 2

Vesicular transport by which substances eXit the cell

Question 3

Two pathways of vesicular transport?

Hint: think timing

Answer 3

1. Constitutive (continuous)
2. Regulated-signal dependent
   **EXO FIRST then ENDO**
   if exo abolished there is no endo

Question 4

Endocytosis: Pinocytosis-micro/macro

Clarithrin in/dependant?

Answer 4

1. Micropinocytosis is continuous and is associated with caveolin and flotillin
   -Clathrin-independent
2. Macropinocytosisis regulated and clathrin-independent
   -requires rearrangement of actin cytoskeleton which causessurface membranes ruffles

Cell drinking

Question 5

Endocytosis: phagocytosis

Answer 5

Ingestion of large particles for degradation
1. Generally performed by specialized phagocytes (macrophage/neutrophils)
2. Receptor mediated-clathrin dependent actin independent
3. Extension of psudopods-actin dependent but clathrin independent

Question 6

What are the fates of ligand-receptor complexes?

Answer 6

1. Receptor recyled and ligand degraded
2. Receptor and ligand recycled
3. Receptor degraded and ligand degraded
4. Receptor & ligand transported through the cell (transcytosis)