Exam 3: Ch 14 Receptor-Mediated Endocytosis Flashcards Preview

Cellular and Molecular Biology > Exam 3: Ch 14 Receptor-Mediated Endocytosis > Flashcards

Flashcards in Exam 3: Ch 14 Receptor-Mediated Endocytosis Deck (22):
1

phagocytosis

nonselective process where extensions of the plasma membrane enveloped ingested material, forming phagosomes

2

receptor-mediated endocytosis

receptor on cell surface binds to extracellular ligand

plasma membrane region with receptor-ligand complex buds inward and pinches off, making a transport vesicle

ex. LDL, transferrin, insulin, glycoproteins

3

receptor mediated endocytosis uses what vesicles

clathrin/AP2

4

can accidentally secreted lysosomal enzymes move back into the cell by receptor mediated endocytosis?

yes, there are M6P receptors on the cell surface

5

what happens to the transmembrane receptors proteins that uptake extracellular ligand

internalized during endocytosis then sorted and recycled back to the cell surface

6

gonads want cholesterol

send to smooth ER

7

lipoprotein

lipid protein complex

shell made of apolipoproteins

cholesterol containing phospholipid monolayer

8

LDL experiment to show how it enters cells

radiolabeled I^125 pulse-chase

electron dense label to LDL

9

order of LDL uptake

surface binding of LDL

internalization

degradation

10

what happens to LDL in lysosomes

apolipoproteins hydrolyzed

cholesterol esterases hydrolyze cholesterol esters

unesterified cholesterol leaves to be used in the cell

11

what about the late endosome causes receptor-ligand complexes to dissociate

acidic pH

receptors recycled back to membrane by exocytosis

12

the endocytic pathway delivers iron to cells without dissociation of the...

receptor-transferrin complex in late endosomes

13

major function of lysosome

degrade extracellular materials and intracellular components

14

pathway to degrade endocytosed membrane proteins in lysosome

uses an unusual vesicle that buds into the lumen of the endosome to produce a multivesicular endosome

eventual fusion with lysosome

15

autophagy

formation of a double membrane organelle known as an autophagosome that enveloped cytosolic material

occurs when cells are placed under stress so macromolecules are used for nutrients

eventual fusion with lysosome

16

what do multivesicular endosomes segregate

membrane proteins destined for lysosomal membrane

proteins destined for lysosomal degradation

17

multivesicular endosomes

endosomes containing many vesicles in their lumen formed from vesicles budding inward

fuses with lysosome to deliver internal vesicles for degradation

18

most cargo proteins entering multivesicular endosomes are tagged with

ubiquitin

19

retroviruses bud from the plasma membrane in a process similar to formation of...

multivesicular endosomes

HIV uses gag protein that attracts ESCRT protein

20

where does the autophagic vesicle come from

experiments show maybe gogi

in starvation... random

21

how do autophagic vesicles grow

fusion with transport vesicles

22

how do autophagic vesicles target the lysosome and fuse

outer membrane has proteins that target lysosome