Cell biology V Flashcards Preview

Year 1 Cell Biology > Cell biology V > Flashcards

Flashcards in Cell biology V Deck (41):
1

Is vesicular transport selective or general?

Selective

2

What is the direction of transport for COP II?

Anterograde - from ER to Golgi

3

What is the direction of transport for COP I?

Retrograde - from Golgi to ER

4

What is the purpose of retrograde transport?

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

5

What are two examples of v-SNAREs?

Synaptotagmin and synaptophysin

6

What is the purpose of SNARE proteins?

Allow vesicle to recognize its target domain

7

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

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

8

What effect do tetanus toxins have on neurons?

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

9

Are mitochondria acidophilic or basophilic?

Acidophilic

10

Define pleomorphic

Ovoid or threadlike structures - motile and can change shape

11

What is the diameter of a typical mitochondrion?

0.5 - 1 um

12

How many mitochondria are there in erythrocytes?

None

13

What is the lifespan of a typical mmitochondrion?

10 days

14

How do mitochondria reproduce?

Fission (can also fuse with each other)

15

Which mitochondrial membrane is selectively permeable?

Inner mitochondrial membrane

16

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

Cardiolipin

17

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

Hepatocytes, cardiac, and muscle cells

18

The cristae of mitochondria are tubular in what cell type?

Steroid-secreting cells

19

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

No

20

What cellular processes occur in the mitochondrial matrix?

TCA cycle, fatty acid B-oxidation

21

Which disease displays "parking lot inclusions" in affected mitochondria?

Myoclonic epilepsy with ragged red fibers (MERRF)

22

What does catalase do?

Enzymatically forms water and oxygen from hydrogen peroxide

23

Where does plasmalogen synthesis occur?

Peroxisome

24

Where are peroxisomal enzymes synthesized?

Cytoplasm

25

What causes Zellweger syndrome?

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

26

What happens to peroxisome levels during chronic administration of antilipidemics?

Increase

27

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

Myelination

28

What are the components of the cytoskeleton?

1) Microtubules2) Microfilaments3) Thick filaments4) Intermediate filaments

29

What is the diameter of microtubules?

24 nm

30

How many longitudinally arranged protofilaments make up a microtubule?

13

31

What makes up the protofilaments of microtubules?

Tubulin dimer subunits

32

What cofactors are required for microtubule synthesis?

1) GTP2) Mg ions

33

What role does gamma-tubulin have in microtubule synthesis?

Microtubules polymerize from a ring of gamma-tubulin

34

What drugs inhibit polymerization of microtubules?

1) Colchicine2) Vinblastine3) Vincristine

35

What drug inhibits depolymerization of microtubules?

Taxol

36

What are the functions of microtubules?

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

37

What is the function of kinesin?

Long-range transport of vesicles toward the periphery

38

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

Serotonin

39

What is the function of dynein?

Long-range transport of vesicles toward the nucleus

40

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

Kinesin

41

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

Dynein