Endomembrane System

Question 1

Rough ER Jobs

Answer 1

1- adding carbs to glycoprotein
2- folding of polypeptides
3- fixing misfolded proteins
4- assembly of multimeric proteins

Question 2

Smooth ER Jobs

Answer 2

1- drug detoxification
2- carb metabolism
3- calcium storage
4- steroid biosynthesis

Question 3

Hydroxylation

Answer 3

NADPH dependent process of adding OH groups to drugs to make them easier to excrete

Question 4

cytochrome p-450

Answer 4

protien catalyst of hydroxylation

Question 5

glucose-6-phosphatase

Answer 5

converts glucose-6-phosphate to free glucose in carb metabolism

Question 6

HMG-CoA reductase

Answer 6

commited step in cholesterol biosynthesis

Question 7

flippases

Answer 7

transfer phospholipids from the cytoplasm to the ER lumen

Question 8

phospholipid exchange (transfer) proteins

Answer 8

move phospholipids to designated organelles (mitochondria, chloroplast, or peroxisomes)

Question 9

Golgi Role

Answer 9

further processing, sorting, and packaging of membrane lipids

Question 10

N-glycosylation/O-glycosylation

Answer 10

Addition of side chains to the N of asparagine or OH of serine, threonine, or tyrosine to create a glycoprotein

Question 11

Core oligosaccharide

Answer 11

2x N-acetylglucosamine, 9x mannose, 3x glucose. Beginning side chain of all glycoproteins until trimmed and modified in the ER lumen

Question 12

cotranslational glycosylation

Answer 12

addition of oligosaccharide as the polypeptide is being formed

Question 13

calnexin/calreticulin/ERp57/UGGT

Answer 13

form a protein complex to promote proper folding and disulfide bond formation of glycoproteins

Question 14

terminal glycosylation

Answer 14

further processing of glycoproteins withing the golgi, involving removal and addition of units to the core oligosaccharide

Question 15

protein tag

Answer 15

targets the protein to a transport vesicle that will take it to the right location

Question 16

posttranslational import

Answer 16

uptake of completed polypeptides with targeting signals into their designated organelle (after translation in cytoplasm)

Question 17

cotranslational import

Answer 17

polypeptide is brought into the ER as synthesis occurs (stays in endomembrane system)

Question 18

signal hypothesis

Answer 18

polypeptides destined for ER have an ER signal sequence that direct the mRNA to the RER

Question 19

preprotein

Answer 19

protein containing an ER signal sequence

Question 20

SRP (signal recognition particle)

Answer 20

mediates the contact of the ribosome to the ER

Question 21

translocon

Answer 21

structure of ER membrane responsible for translocation of polypeptides across the ER membrane

Question 22

retention tag

Answer 22

protien tag that keeps them in the ER

Question 23

retrieval tag

Answer 23

tag on proteins that return from the golgi to the ER

Question 24

mannose-6-phosphate

Answer 24

tag that sends lysosomal proteins to lysosomes

Question 25

Hsp70

Answer 25

chaperone that keeps the protein unfolded during posttranslational import

Question 26

sec62/63/7172 and Sec6

Answer 26

protein complex that targets cytosolic proteins for translocation

Question 27

BiP + ATP hydrolysis

Answer 27

pulls polypeptide into ER lumen

Question 28

constitutive secretion

Answer 28

vesicles move directly to cell membrane and fuse with plasma membrane

Question 29

regulated secretion

Answer 29

vesicles accumulate in the cell and fuse with membrane ONLY in response to specific signals

Question 30

polarized secretion

Answer 30

exocytosis limited to specific surface of the cell

Question 31

Clathrin depended endocytosis

Answer 31

ligands bind to receptors on the membrane surface to internalize macromolecules

Question 32

fluid-phase endocytosis

Answer 32

pinocytosis for nonspecific internalization of extracellular fluid

Question 33

coated vesicles

Answer 33

vesicles in protien/lipid transport covered in layers of protein (clathrin/COPI/COPII)

Question 34

caveolin/clathrin/COPI/COPII

Answer 34

proteins associated with coating vesicles for transport

Question 35

Clathrin/adaptor protien(AP)/dynamin

Answer 35

coats involved in clathrin-coated vesicles

Question 36

triskelion

Answer 36

3-legged structure of clathrin proteins

Question 37

AP complexes

Answer 37

sites of regulation of clathrin assembly/disassembly (ATP/GTP dependent)

Question 38

dynamin

Answer 38

required for constricting and closing clathrin vesicles

Question 39

COPI/COPII

Answer 39

involved in retrograde transport from golgi to ER and between golgi cisternae

Question 40

SNARE/SNAP protein

Answer 40

Involved in proper sorting and targeting of vesicles. Allow recognition between vesicles and targets

Question 41

v-SNARE

Answer 41

SNARE proteins found in vesicles

Question 42

t-SNARE

Answer 42

SNARE proteins found on target membranes

Question 43

acid hydrolases

Answer 43

Enzymes found in lysosomes. Activation is the last step in lysosomal development from endosome --> lysosome

Question 44

Heterophagic lysosome

Answer 44

contain substances that originated outside the cell

Question 45

autophagic lysosome

Answer 45

contain materials originating inside the cell

Question 46

residual body

Answer 46

lysosomes once digestion ceases

Question 47

autophagy

Answer 47

method of breaking down cellular structures that are damaged or unneeded

Question 48

macrophagy

Answer 48

form of autophagy where an organelle is wrapped in a double membrane from the ER forming an autophagosome

Question 49

microphagy

Answer 49

form of autophagy in which a small vacuole is surrounded by a single membrae bilayer

Question 50

glycogeneosis/hurler/tay-sachs

Answer 50

lysosomal storage diseases leading to the accumulation of substances that cannot be broken down

Question 51

plant vacuole

Answer 51

Act as lysosomes as well as maintaining turgor pressure, regulating pH, and storage

Question 52

peroxisome

Answer 52

Vesicle stemming from the ER that contains catalase and cyrtalline. 1- Peroxide metabolism 2- Detoxification 3- Fatty acid oxidation 4- Metabolize N-containing compounds 5- Catabolism of unusual substances

Question 53

plant peroxisomes

Answer 53

associated with aspects of cell energy metabolism and in close contact with mitochondria and chloroplasts

Question 54

glycoxysomes

Answer 54

specialized plant peroxisome in seedlings

Question 55

peroxins

Answer 55

proteins required for the process of increasing number of peroxisomes in a cell