Endoplasmic reticulum

Question 1

Important for intracellular —-storage

Answer 1

Ca+

Question 2

RER makes most__ destined for secretion

Answer 2

protein

Question 3

___embedded in the ER gives the rough appearance

Answer 3

ribosomes

Question 4

Rough Er is the site of protein—- and —— also lipid —-

Answer 4

production and modification
lipid synthesis

Question 5

Smooth ER is involved in lipid——, production of ——-and detoxification of —-

Answer 5

metabolism production of lipoprotein particles and detoxification of lipid soluble drugs

Question 6

Transition ER are areas of—

Answer 6

smooth ER which form transport vesicles fro delivery to the Golgi

Question 7

Smooth ER is important for intracellular —storage

Answer 7

Ca2+

Question 8

Smooth microsomes have —-density and stop sedimenting and float at low sucrose concentration

Answer 8

low

Question 9

Rough microsomes have a —-density and stop sedimenting and float at high sucrose concentration

Answer 9

high

Question 10

ER reseals upon homogenization to form ——

Answer 10

microsomes

Question 11

Proteins are either imported ——-or——-

Answer 11

co-translationally or post-translationally

Question 12

Proteins are built from —- to —- term

Answer 12

N to C

Question 13

The endomembrane system is composed of

Answer 13

the ER, Golgi, endosomes and lysosomes

Question 14

RER appears in the ——micrographs b/c?

Answer 14

EM b/c of the ribosomes

Question 15

RER is important for

Answer 15

protein folding and processing

Question 16

What are the three ways proteins get translated?

Answer 16

translated completed
unfolded and then transported inot the ER lumen
co-translationally translocated

Question 17

The smooth ER is important for?

Answer 17

storing calcium and detoxifying drugs

Question 18

Both RER and SER are important for?

Answer 18

lipid biosynthesis

Question 19

Proteins can enter the ER by which two ways?

Answer 19

post-translationally or co-translationally translocated

Question 20

Co-translational translocation is dependent on?

Answer 20

an N-terminal signal sequence
the signal recognition patricle(SRP)
the SRP receptor and the translocon

Question 21

What do stop transfer sequences allow for?

Answer 21

transmembrane domains to insert in cell membranes

Question 22

What do start transfer sequences allow?

Answer 22

Non-N-terminal portions of the protein to iniate translocation

Question 23

Combination of start and stop sequences allow?

Answer 23

production of multi pass transmembrane proteins as well as transmembrane proteins with C rather then N terminus to the ER lumenal side

Question 24

What is N-linked glycosylation?

Answer 24

During translocation a block of 14 carbohydrates may be covalenty attached to the nitrogen on a asparagin residue within the recognition sequence Asn-X-Ser/Thr

Most proteins made at the RER are N-glycosylation in a co-translational manner by Oligosaccharyltransferase( a transmembrane protein complex of the RER)

Question 25

The N-linked carbohydrates are only added in the —-and modified in the —-

Answer 25

ER Er and Golgi

Question 26

p450 enzymes are associated with

Answer 26

SER membranes

Question 27

p450 can?

Answer 27

oxidize drugs, this increases their solubility and may introduce OH groups which are sites for conjugation

Question 28

What is conjugation?

Answer 28

is the process by which fairly large soluble molecules are covalently attached to OH groups which allows drugs to be removed by kidneys or intestines

Question 29

What is the Golgi important for?

Answer 29

protein modification and sorting

Question 30

The golgi is the site for?

Answer 30

O-linked glycosylation, which makes up about 10% of all protein glycosylation

Question 31

What are the three components of the Golgi?

Answer 31

cis Golgi network medial cisternae tran Golgi network proteins have to move through this network in endosomes !> stationary cisternae model-vesiclules moving 2.cisternal maturation model-Sack matures into trans Anterograde movement is ER-Golgi-plasma membrane Retrograde Vesicleus-golgi-ER

Question 32

The three compartments of the Golgi carry out ——functions thus requiring a —-of enzymes

Answer 32

distinctive specific set These enzymes must have either a system for retention or retrieval

Question 33

____secretion occurs continuously

Answer 33

constitutive

Question 34

—-secretion requires specific signal

Answer 34

regulated

Question 35

Acid hydroplanes are modified by? This allows them to? What happens when the pH drops? What happens when this fails?

Answer 35

A mannose-6-phosphate(M6P) moiety in the golgi. This allows the, top binds to a M6P receptor which they are then packed into vesicles going to the lysosomes. As the pH drops, the cargo and receptor separate, with the receptor returning to the Golgi and the cargo going on to the lysosome. Failure leads to one or more hydrolases in the lysosomes, which mean cellular components are not broken down correctly. These diseases are collectively called as lysosomal storage diseases.

Question 36

Secretion via vesicles is called?

Answer 36

ecocytosis

Question 37

____can physically move vesicles around the cell. This requires any inputs of energy.

Answer 37

Motor proteins

Question 38

What are the three types are motor proteins?

Answer 38

Kinesins dyneins myosins

Question 39

____move towards the plus end of the mircotubules

Answer 39

kinesins

Question 40

____move towards the minus end of the mircotubules

Answer 40

dyneins

Question 41

___move along microfilaments

Answer 41

myosins

Question 42

Endocytosis

Answer 42

taking components from outside the cell in vesicles

Question 43

___is similar to endocytosis but it involves cytoskeletal rearrangements and it can be used to bring very large macromolecules even other cells into the cell

Answer 43

phagocytosis

Question 44

Selection of endocytosis can be______ or ______

Answer 44

non-selective-pinocytosis selective-receptor-mediated

Question 45

___form the vesicle, and they may be important for cargo selection by associating directly or indirectly with receptors

Answer 45

Coat proteins

Question 46

The LDL-receptor associates indirectly with the____, allowing for selective uptake of LDL

Answer 46

coat protein clathrin

Question 47

What are the three coat proteins?

Answer 47

Clathrin COPI COPII

Question 48

Clathrin

Answer 48

out from the Golgi and in from plasma membrane triskelion-3 large and 3 small polypeptides polymerizes into a soccer ball shape Coat assembly initiated by ARFs(GTPase) Dynamin(GTPase) pinches off membrane

Question 49

COPI

Answer 49

back from Golgi to ER initiated by ARF

Question 50

COPII

Answer 50

out from ER utilizes Sar1 for initiation

Question 51

Initiation of coat formation if mediated by

Answer 51

monomeric GTPases

Question 52

Pinching off the vesicle requires a —

Answer 52

second monomeric GTPases called dynamin

Question 53

Vesicular targeting requires a third monomeric GTPas called

Answer 53

Rab

Question 54

SNARE complexes?

Answer 54

mediate membrane fusion of vesicles and target membranes. Generally there is a single helix on a vesicle and 3 on the target membrane. These spontaneously fold into a four helical bubble when they are close. The energy released from formation is used to drive membrane fusion, which is an unfavourable process