Protein Trafficking

Question 1

Gated transport

Answer 1

specific macromolecules allows to move

Question 2

Transmembrane transport

Answer 2

protein translocators move protein by denaturing them

Question 3

vesicular ttransport

Answer 3

membrane enclsoed strucutres move proteins as cargo

Question 4

Signal sequence

Answer 4

continuous sequence at N terminus or internally embedded

Question 5

Signal patches

Answer 5

many internal sequences that are not cleaved

Question 6

nuclear pore complex

Answer 6

made of nucleoporins that have 8 subunits, cytosolic fibrils and a nuclear basket

Question 7

nuclear localization signal

Answer 7

has Lys and Arg residues; make nuclear importation specific

Question 8

nuclear import/export receptor

Answer 8

has 2 binding sites: nuclear localization signal and nuclear pore complex

Question 9

Mitochondrial transport

Answer 9

Hsp70 binds signal sequence and keeps protein unfolded until it is in the mitochondria
if in matrix-N terminal cleaved
if in inner, outer, or intermembrane-internal

Question 10

Co-translation import

Answer 10

while the protein is being made, the SRP will bind the hydrophobic stretch, stop translation, attach to SRP receptor on ER and continue peptide growth in the translocon on the ER

Question 11

ER signal sequence

Answer 11

N terminal leader is cleaved later

Question 12

Signal receptor particle

Answer 12

binds signal sequence and large subunit, stops translation and binds to its receptor

Question 13

SRP receptor

Answer 13

located on the ER and binds SRP molecule and complex, allows translation to continue to the ER

Question 14

Unfolded proteins

Answer 14

are sent back to the cytosol;

in the ER, membrane sensors detect when there are too many unfolded proteins that accumulated

Question 15

ER response to unfolded proteins

Answer 15

regulate splicing
recruit chaperones
down regulate protein translation

Question 16

exocytosis

Answer 16

move stuff out

Question 17

endocytosis

Answer 17

bring things in

Question 18

coated vesicles

Answer 18

concentrate contents and mold vesicles forming

Question 19

clathrin vesicles

Answer 19

come from PM; made of clathrin triskelions

Question 20

COPI vesicles

Answer 20

come from Golgi

Question 21

COPII vesicles

Answer 21

come from ER

Question 22

ER retrieval signal

Answer 22

C terminal Lys seq or KDEL

proteins bind COPI coats or KDEL receptors and are returned

Question 23

Golgi network

Answer 23

proteins moves cis-median-trans

Question 24

Lysosomes

Answer 24

have acid hydrolaes, H+ ATPase and zymogens

Question 25

acid hydrolases

Answer 25

hydrolytic enzymes that digest macromolecules

Question 26

H+ ATPase

Answer 26

pump H+ ions and acidify interior

Question 27

zymogens

Answer 27

inactive form of enzyme; has to be activated by proteolytic cleavage to have effect

Question 28

maturation of lysosomes

Answer 28

early endosome-encapsulate endocytosed molcules
late endosome-mild acidic interior; bring proteins in; hydrolyti digestion begins (pH=6)
endolysosome-late endosome + existing lysosome (pH 4.5-5)

Question 29

Autophagy

Answer 29

autophagosome enclosed organelle, fuses with lysosome, digests it

Question 30

Phagocytosis

Answer 30

large particles taken up

Question 31

pinocytosis

Answer 31

fluid and small molecules taken up

Question 32

constitutive secretion

Answer 32

continuous secretion without regard to environmental factors; no regulation

Question 33

regulated secretion

Answer 33

packed the same but secreted in response to a specific signal (neural or hormonal)