Chapter 12

Question 1

network of membrane-enclosed tubules and sacs (cisternae) - extends from nuclear membrane throughout cytoplasm.

Answer 1

ER

Question 2

the secretory pathway

Answer 2

Rough ER → Golgi → secretory vesicles → cell exterior

Question 3

Proteins synthesized on _______ stay in the cytosol or are transported to the nucleus and other organelles.

Answer 3

free ribosomes

Question 4

Proteins synthesized on __________ are translocated directly into the ER through translocon.

Answer 4

membrane-bound ribosomes

Question 5

Proteins move into the ER during their synthesis on membrane-bound ribosomes.

Answer 5

Cotranslational translocation

Question 6

Proteins move into the ER after translation has been completed on free ribosomes.

Answer 6

Posttranslational translocation

Question 7

cytosol is a _____ environment

Answer 7

reducing

Question 8

the ER is a ______ environment

Answer 8

oxidizing

Question 9

misfolded proteins removed from ER by

Answer 9

ERAD

Question 10

If an excess of unfolded proteins accumulates, a signaling pathway called the ______ is activated.

Answer 10

unfolded protein response (UPR)

Question 11

Eukaryotic membranes are made of 3 lipid types:

Answer 11

phospholipids, glycolipids, and cholesterol.

Question 12

Most of phospholipids are synthesized on the _____ side of the ER membrane from water-soluble precursors (glycerol).

Answer 12

cytosol

Question 13

passage of polar head groups through the membrane occurs by:

Answer 13

flippases

Question 14

a targeting sequence at the carboxy terminus that directs retrieval back to the ER. (2 examples)

Answer 14

KDEL or KKXX

Question 15

Most glycolipids and sphingomyelin are synthesized in the

Answer 15

Golgi.

Question 16

receives molecules from the ERGIC

Answer 16

cis compartment

Question 17

most modifications are done here

Answer 17

medial/trans compartments

Question 18

the sorting and distribution center

Answer 18

trans-Golgi network

Question 19

Transport vesicles with secretory proteins are coated with

Answer 19

coat proteins.

Question 20

COPII-coated vesicles carry proteins from the

Answer 20

ER to the ERGIC

Question 21

COPI-coated vesicles carry proteins to

Answer 21

their early compartments

Question 22

Clathrin-coated carry proteins

Answer 22

in both directions

Question 23

Interaction between transport vesicles and target membranes is mediated by

Answer 23

tethering factors

Question 24

membrane-enclosed organelles that contain enzymes to break down all types of biological polymers

Answer 24

lysosomes

Question 25

Gaucher disease affects what organelle

Answer 25

lysosomes

Question 26

Lysosomes digest material taken up from outside the cell by

Answer 26

endocytosis

Question 27

turnover of the cell’s own components.

Answer 27

autophagy