ER, Golgi & Secretion

Question 1

What is the ER attached to?

Answer 1

nuclear envelope

Question 2

What is the ER made of?

Answer 2

tubules and cisternae

Question 3

What is the function of the ER

Answer 3

calcium store

Question 4

What are located on the rough ER

Answer 4

ribosomes

Question 5

What are translated on ribosomes?

Answer 5

transmembrane protein

Question 6

What are the functions of the Rough ER?

Answer 6

Protein folding, storage, transport, detoxification

Question 7

What does the rough ER store

Answer 7

proteins

Question 8

What are the functions of the smooth ER?

Answer 8

phospholipid synthesis, steroid hormone production, synthesis & storage of glycerides and glycogen

Question 9

Does the smooth ER store calcium?

Answer 9

YES

Question 10

What do secretory granules contain (in acinar cells)?

Answer 10

digestive enzymes

Question 11

What are secretory granules packed with digestive enzymes called?

Answer 11

zymogen granules

Question 12

What causes vesicle fusion and enzyme release?

Answer 12

Ca2+ release

Question 13

Is the release of calcium SUFFICIENT or NECESSARY to release digestive enzymes?

Answer 13

SUFFICIENT

Question 14

What do zymogen granules fuse with?

Answer 14

plasma membrane

Question 15

what happens when zymogen granules fuse with the plasma membrane?

Answer 15

digestive enzymes are released into the extracellular space

Question 16

What is the sarcoplasmic reticulum?

Answer 16

ER in muscle cells

Question 17

How is mobilisation of calcium important for the cell

Answer 17

muscle contraction - interaction of calcium & troponin expose myosin binding site

Question 18

What is the Golgi formed from?

Answer 18

Several flattened cisternae

Question 19

Which face of the Golgi is close to the ER

Answer 19

forming face - cis face

Question 20

From which face of the Golgi do vesicles bud off from?

Answer 20

Maturing face - trans face

Question 21

Meaning of juxta-nuclear

Answer 21

lies close to the nucleus

Question 22

TRUE or FALSE - Golgi is juxtanuclear

Answer 22

TRUE

Question 23

How do cisternae communicate with the ER and cell membrane

Answer 23

Using vesicles and tubules

Question 24

What is the function/s of the Golgi

Answer 24

modify and package secretions, renewal & modification of PM, deliver material to organelles & PM

Question 25

What are the three types of vesicle coats

Answer 25

COPI, COPII, and clathrin

Question 26

What is the function of vesicle coats

Answer 26

aid formation of the vesicle

Question 27

What do vesicle coats prevent

Answer 27

fusion

Question 28

When are vesicle coats discarded?

Answer 28

before fusion with target

Question 29

Where are t-SNAREs located

Answer 29

target membrane

Question 30

Where are v-SNAREs located

Answer 30

vesicle membrane

Question 31

What are the functions of SNAREs?

Answer 31

promote fusion, ensure each vesicle goes to the right place

Question 32

What type of proteins are SNAREs

Answer 32

transmembrane proteins with large cytoplasmic domains

Question 33

What happens when two SNAREs fuse?

Answer 33

form alpha helical bundles, membranes are close together

Question 34

Where does fusion of SNAREs usually occur?

Answer 34

Nerve terminals for the docking of synaptic vesicles

Question 35

What are the two models for progression through the golgi?

Answer 35

vesicular transport model, cisternal maturation

Question 36

What are the three pathways controlling movement of vesicles?

Answer 36

Signal mediated diversion to lysosomes, constitutive secretory pathway, signal mediated diversion to secretory vesicles

Question 37

What forms COPII vesicles

Answer 37

ER exit sites

Question 38

What is the function of endocytosis

Answer 38

take up large components

Question 39

What are lysosomes full of

Answer 39

hydrolytic enzymes

Question 40

What is the function of lysosomes

Answer 40

hydrolyses and lipases

Question 41

What is the function of pseudopods?

Answer 41

engulfing

Question 42

What are pseudopods?

Answer 42

arms that come out of the cell

Question 43

What is key for function of the endocytic pathway

Answer 43

gradient of pH

Question 44

Describe phagocytosis

Answer 44

uptake of really large particles

Question 45

What is frustrated phagocytosis

Answer 45

when associated macrophages dont fuse

Question 46

What type of signalling does phagocytosis use

Answer 46

autonomous

Question 47

Describe dictyostelium

Answer 47

express actin related protein

Question 48

What is macropinocytosis

Answer 48

ruffling of the membrane

Question 49

what is the function of macropinocytosis

Answer 49

trap and internalise material

Question 50

Describe the receptors on LDLs

Answer 50

internalised

Question 51

What can clathrin be easily purified from

Answer 51

bovine brain or placenta

Question 52

Describe the structure of clathrin coated pits

Answer 52

hexagonal and pentagonal - polymerises to form lattice

Question 53

Why is clathrin coat removed

Answer 53

to allow access to SNAREs

Question 54

What is the function of dynamin

Answer 54

helps pinch off clathrin coated vesicles

Question 55

What is the function of Rab proteins

Answer 55

define intracellular organelles and ensure they maintain their identity

Question 56

What is the function of dictyostelium

Answer 56

take up yeast and mobilise actin cytoskeleton