Cell biology V

Question 1

Is vesicular transport selective or general?

Answer 1

Selective

Question 2

What is the direction of transport for COP II?

Answer 2

Anterograde - from ER to Golgi

Question 3

What is the direction of transport for COP I?

Answer 3

Retrograde - from Golgi to ER

Question 4

What is the purpose of retrograde transport?

Answer 4

To return membrane, v-SNARE, and missorted proteins back to the ER

Question 5

What are two examples of v-SNAREs?

Answer 5

Synaptotagmin and synaptophysin

Question 6

What is the purpose of SNARE proteins?

Answer 6

Allow vesicle to recognize its target domain

Question 7

What effect do the neurotoxins of tetanus and botulism have on SNAREs?

Answer 7

The toxins enter nerve terminals and proteolyse SNARE proteins, preventing vesicles containing neurotransmitters from docking with pre-synaptic membranes of the nerve cell

Question 8

What effect do tetanus toxins have on neurons?

Answer 8

Enter inhibitory neurons, proteolyse SNAREs, and release brake on the neuron

Question 9

Are mitochondria acidophilic or basophilic?

Answer 9

Acidophilic

Question 10

Define pleomorphic

Answer 10

Ovoid or threadlike structures - motile and can change shape

Question 11

What is the diameter of a typical mitochondrion?

Answer 11

0.5 - 1 um

Question 12

How many mitochondria are there in erythrocytes?

Answer 12

None

Question 13

What is the lifespan of a typical mmitochondrion?

Answer 13

10 days

Question 14

How do mitochondria reproduce?

Answer 14

Fission (can also fuse with each other)

Question 15

Which mitochondrial membrane is selectively permeable?

Answer 15

Inner mitochondrial membrane

Question 16

Which molecule is responsible for the decreased permeability of the inner mitochondrial membrane?

Answer 16

Cardiolipin

Question 17

The cristae of mitochondria are shelf-like in what cell type?

Answer 17

Hepatocytes, cardiac, and muscle cells

Question 18

The cristae of mitochondria are tubular in what cell type?

Answer 18

Steroid-secreting cells

Question 19

Does the morphology of cristae have an effect on mitochondria function?

Answer 19

No

Question 20

What cellular processes occur in the mitochondrial matrix?

Answer 20

TCA cycle, fatty acid B-oxidation

Question 21

Which disease displays “parking lot inclusions” in affected mitochondria?

Answer 21

Myoclonic epilepsy with ragged red fibers (MERRF)

Question 22

What does catalase do?

Answer 22

Enzymatically forms water and oxygen from hydrogen peroxide

Question 23

Where does plasmalogen synthesis occur?

Answer 23

Peroxisome

Question 24

Where are peroxisomal enzymes synthesized?

Answer 24

Cytoplasm

Question 25

What causes Zellweger syndrome?

Answer 25

Peroxisomal enzymes are not transported into the peroxisome due to defective import protein on the unit membrane of the peroxisome

Question 26

What happens to peroxisome levels during chronic administration of antilipidemics?

Answer 26

Increase

Question 27

What process in nerve cells is impaired due to defective plasmalogen synthesis?

Answer 27

Myelination

Question 28

What are the components of the cytoskeleton?

Answer 28

1) Microtubules2) Microfilaments3) Thick filaments4) Intermediate filaments

Question 29

What is the diameter of microtubules?

Answer 29

24 nm

Question 30

How many longitudinally arranged protofilaments make up a microtubule?

Answer 30

13

Question 31

What makes up the protofilaments of microtubules?

Answer 31

Tubulin dimer subunits

Question 32

What cofactors are required for microtubule synthesis?

Answer 32

1) GTP2) Mg ions

Question 33

What role does gamma-tubulin have in microtubule synthesis?

Answer 33

Microtubules polymerize from a ring of gamma-tubulin

Question 34

What drugs inhibit polymerization of microtubules?

Answer 34

1) Colchicine2) Vinblastine3) Vincristine

Question 35

What drug inhibits depolymerization of microtubules?

Answer 35

Taxol

Question 36

What are the functions of microtubules?

Answer 36

1) Structural support of cytoplasm2) Organelle support3) Cell division4) Motility of cilia and flagella5) Long-range transport of vesicles via motor proteins

Question 37

What is the function of kinesin?

Answer 37

Long-range transport of vesicles toward the periphery

Question 38

A defect in kinesin has been shown to decrease the transport of receptors for what hormone?

Answer 38

Serotonin

Question 39

What is the function of dynein?

Answer 39

Long-range transport of vesicles toward the nucleus

Question 40

What molecule is responsible for long-range transport of vesicles toward the periphery of the cell?

Answer 40

Kinesin

Question 41

What molecule is responsible for long-range transport of vesicles toward the nucleus?

Answer 41

Dynein