Secretory pathways I

Question 1

Proteins move through _______ across a membrane from the cytosol into an organelle

Answer 1

translocators

Question 2

Peptide synthesis is initiated on

Answer 2

ribosomes in the cytoplasm

Question 3

A signal sequence is reached during synthesis that signals for the

Answer 3

translocation of the growing peptide into the ER

Question 4

_______ binds the translated signal sequence and free ribosome

Answer 4

A signal recognition particle

Question 5

SRP has a _______ rich binding binding pocket that allows it to be flexible in terms of what it binds

Answer 5

methionine

Question 6

SRP then binds _______ and halts _______

Answer 6

• GTP

- elongation of the peptide

Question 7

The ribosome and peptide are brought to

Answer 7

SRP receptors on the cytosolic face of the ER

Question 8

The growing peptide is transferred to a

Answer 8

translocon complex

Question 9

SRP dissociates from the complex as _______ is hydrolyzed

Answer 9

GTP

Question 10

SRP dissociates from the complex as GTP is _______

Answer 10

hydrolyzed

Question 11

Elongation of the peptide continues, feeding the growing peptide into the

Answer 11

lumen of the ER

Question 12

After synthesis is complete, the signal sequence is cleaved by _______ and the _______ dissaciates and is recycled

Answer 12

• signal peptidase

- ribosome

Question 13

Cargo proteins are released into

Answer 13

the lumen of the ER

Question 14

Transmembrane proteins differ in that they contain a transmembrane domain called the

Answer 14

stop transfer sequence

Question 15

Type 1 transmembrane proteins have their amino terminus

Answer 15

inside the lumen

Question 16

Type 2 transmembrane proteins have their amino terminus

Answer 16

outside the lumen