Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 1 Cell Biology > Cell biology II > Flashcards

Cell biology II Flashcards

1
Q

What is the contribution, in percentage, of proteins to the plasmalemma?

A

25-75%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Beta-amyloid precursor protein is important in what (five) cellular processes?

A

1) Neuronal migration during development2) Synaptic formation and repair3) Cell signaling4) Long-term potentiation5) Cell adhesion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the causative molecule involved in Creutzfeld-Jakob disease?

A

A variant prion protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the normal prion protein (PrP) involved in, normally?

A

Cell surface, glycosylated GPI anchor within lipid rafts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the variant prion protein do in Creutzfeld-Jakob disease?

A

Crosslinks filaments that are resistant to proteolysis and accelerates formation of other variants of the same form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Normal prion proteins are implicated in what cellular processes?

A

1) Neuroprotective against ischemia2) Control Circadian rhythms3) Serve to organize myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do carrier proteins do?

A

Transport one or two chemicals in one direction, or two molecules in opposite directions without energy expenditure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are protein pumps?

A

Transport proteins requiring the direct expenditure of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the Na/K pump do?

A

1) Cleaves ATP to transport three Na out of the cell and two K into the cell2) Functions to regulate intracellular volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does digoxin do?

A

Partially inhibits Na/K pump, leading to decreased activity of Ca/Na transporter. Result is an increase in sarcoplasmic [Ca]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are multidrug resistant transporters (MDRs)?

A

Subfamily of primary transporter proteins that are ATPases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where is MDR-1 expressed?

A

1) Kidney2) Intestine3) Liver4) BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does overexpression of MDR cause?

A

Causes some cancer cells to become resistant to cytotoxic drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is MDR-1 overexpression combatted pharmacologically?

A

1) RNA interference2) Pharmacological inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does MDR-2 transport?

A

Direct bilirubin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which transporter is responsible for direct bilirubin?

A

MDR-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which protein is defective in Dubin-Johnson Syndrome?

A

MDR-2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

A defect in MDR-2 leads to what disease?

A

Dubin-Johnson Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is MDR-3 expressed?

A

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the function of MDR-3?

A

Flippase of phosphatidylcholine - flips it to the the outer canalicular membrane of hepatocytes so that it may be excreted into bile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are aquaporins?

A

Protein channels for water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the protein channels for water called?

A

Aquaporins

23
Q

How many isoforms of aquaporins are there?

A

12

24
Q

Aquaporin-2 is expressed by what type of cell?

A

Renal collecting tubule cells

25
Q

Renal collecting tubule cells express what protein channel, specifically?

A

Aquaporin-2

26
Q

What induces translocation of aquaporin receptors to the plasma membrane of collecting tubule cells?

A

Vasopressin

27
Q

What does the translocation of aquaporin receptors to the plasma membrane of collecting tubule cells do to water reabsorption across their apical domain?

A

Increases reabsorption

28
Q

Nephrogenic diabetes insipidus results from mutation of both ________ genes

A

Aquaporin-2

29
Q

Mutations in both genes of aquaporin-2 results in what disease?

A

Nephrogenic diabetes insipidus

30
Q

What kind of channel is CFTR?

A

Chloride channel

31
Q

What does CFTR regulate in addition to chloride?

A

Na and HCO3-

32
Q

Na and HCO3- is regulated by what channel?

A

CFTR

33
Q

Where are glycolipids found, exclusively?

A

Noncytosolic lipid monolayer (also found in some intracellular membranes)

34
Q

What glycolipid serves as a receptor for cholera toxin?

A

Ganglioside Gm1

35
Q

Ganglioside Gm1 serves as a receptor what what toxin?

A

Cholera toxin

36
Q

What does cholera toxin do once it binds to ganglioside Gm1 receptor?

A

Ramps up synthesis of cAMP, leading to efflux of Na and water into intestinal lumen

37
Q

Carbohydrates in the plasmalemma have what charge?

A

Negative

38
Q

What are the five pathways for endocytosis?

A

1) Macropinocytosis2) Clathrin-mediated endocytosis3) Non-coated-mediated endocytosis4) Caveolae-mediated endocytosis (Simian virus 40)5) Phagocytosis

39
Q

Where does macropinocytosis occur?

A

Thyroid cells as they take up thyroglobulin and dendritic cells for immune surveillance

40
Q

Macropinocytosis relies on what type of cytoskeletal element?

A

Actin

41
Q

Is macropinocytosis specific or nonspecific for its substrate?

A

Nonspecific

42
Q

What molecule is required to pinch off the vesicle in clathrin-mediated endocytosis?

A

Dynamin (GTPase)

43
Q

Can clathrin-mediated endocytosis be mediated by receptors?

A

Yes

44
Q

What are two examples of receptor-mediated clathrin-mediated endocytosis?

A

1) Cholesterol (in LDL form) 2) Protein hormones

45
Q

Where are cargo receptors located in clathrin-mediated endocytosis?

A

Coated pits

46
Q

What molecule associates with the intracellular portion of the cargo receptor in clathrin-mediated endocytosis?

A

Adaptin

47
Q

What is the role of adaptin in clathrin-mediated endocytosis?

A

Associates with the intracellular portion of the cargo receptor

48
Q

What condition occurs when there is a decrease or defect in LDL receptors?

A

Atherosclerosis

49
Q

Recycling of synaptic vesicles is performed by what type of endocytosis?

A

Clathrin-mediated endocytosis

50
Q

Cholera and Shiga toxins enter the cell via what endocytotic mechanism?

A

Non-coated-mediated endocytosis

51
Q

Is phagocytosis receptor-mediated?

A

Yes, generally (zipper-mediated)

52
Q

Phagocytosis is dependent on what type of cytoskeletal component?

A

Actin

53
Q

Does phagocytosis require clathrin?

A

No

54
Q

What do phagosomes fuse with?

A

Lysosomes

Year 1 Cell Biology (40 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions