1D Foundations 4 - Cell Biology-Cytoplasm & Cytoskeleton

Question 1

What are the 4 basic types of filaments that make up the cytoskeleton?

Answer 1

Microfilaments
Intermediate filaments
Myosin
Microtubules

Question 2

Major role played by Actin?

Answer 2

Cellular motility

Question 3

Major role of Myosin?

Answer 3

Generates muscle contraction

Question 4

Vimentin has which functions?

Answer 4

Support cellular membranes. Keeo certain organelles fixed in cytoplasm

Question 5

Vimentin is a structural component of and include?

Answer 5

Connective tissue.

Fibroblasts, Leukocytes, Endothelium

Question 6

Desmin is a structural component of?

Answer 6

Muscle cells (smooth, skeletal, heart)

Question 7

Cytokeratin is a structural component of?

Answer 7

Epithelial cells (keratin in desmosomes and hemidesmosomes)

Question 8

Glial fibrillary acid proteins (GFAP) is a structural component of?

Answer 8

Astrocytes, Schwann cells, other neuroglia

Question 9

Peripherin is a structural component of?

Answer 9

Neurons

Question 10

Neurofilaments (L, M. H molecular weight) are structural components of?

Answer 10

Axons within neurons

Question 11

Nuclear lamins (A, B, C) are structural components of?

Answer 11

Nuclear envelope and DNA within

Question 12

Mention 7 Intermediate filament structures

Answer 12

Vimentin
Desmin
Cytokeratin
Glial fibrillary acid protein (GFAP)
Peripherin
Neurofilaments (L, M, H molecular weight)
Nuclear lamins (A, B, C)

Question 13

Nuclear lamin mutation disorders:

Answer 13

Progeria

Muscular dystrophy

Question 14

Staining Vimentin can indicate which cancer(s)?

Answer 14

• Sarcomas

- Some carcinomas

Question 15

Stain of Desmin can identify which cancer?

Answer 15

Myosarcoma (Rhabdomyosarcoma or leiomyosarcoma)

Question 16

Stain of Cytokeratin can identify which cancer?

Answer 16

Carcinoma (cancer of epithelial cells)

Question 17

Stain of GFAP can identify which cancer?

Answer 17

Astrocytomas, Glioblastoma

Question 18

Stain of Neurofilaments can identify which cancers?

Answer 18

Neuroblastomas (Childhood cancer that arises from sympathetic ganglion of the adrenal medulla).
Primitive neuroectodermal tumours

Question 19

Microtubules consists of?

Answer 19

Alpha- & beta-tubulin making up heterodimers put together in a cylindrical structure in a helical fashion.

Question 20

Microtubules are incorporated into which structures?

Answer 20

-Flagella and cilia
-Mitotic spindles
(Grows slowly and collapses quickly)

Question 21

Drugs that block microtubule polymerization

Answer 21

Vinca alkaloids (cancer drugs):

• Vincristine
• Vinblastine

Question 22

Drugs that hyperstabilize microtubules (so they can’t break down and separate chromosomes during mitosis)

Answer 22

Taxanes (cancer drugs):

• Paclitaxel
• Docetaxel

Question 23

Drugs that act on microtubules (antihelminthics)

Answer 23

Benzimidazoles

• Mebendazole
• Albendazole
• Thiabendazole

Question 24

Drugs that act on microtubules (Antifungal)

Answer 24

Griseofulvin

Question 25

Drugs that act on microtubules (anti-gout, anti-inflammatory)

Answer 25

Colchicine (prevent phagocyte movement)

Question 26

Name two molecular motor proteins that are involved in axonal transport

Answer 26

Dynein and Kinesin

Question 27

Kinesin and Dyenein moves from to on the microtubule?

Answer 27

Kinesin: - –> + (Anterograde)
Dynein: + –> - (Retrograde)

Question 28

Cilium structure?

Answer 28

9+2 Microtubule doublet arrangement and 9 Dynein arms

Question 29

Where does one find cilia?

Answer 29

Respiratory tract:
-Trachea
-Bronchioles
Paranasal sinuses
Fallopian tubes

Question 30

How is coordinated ciliary movement coordinated between ciliated cells?

Answer 30

Through Gap junctions

Question 31

What is the cause of Primary Ciliary Dyskinesia?

Answer 31

Immotile cilia due to dynein arm defect

Question 32

Symptoms of Primary Ciliary Dyskinesia?

Answer 32

• Infertility
• Bronchiectasis
• Chronic sinusitis
• 50% has situs inversus

Question 33

Triad of Kartagener syndrome?

Answer 33

• Situs inversus
• Bronchiectasis
• Chronic sinusitis

Question 34

Soluble things in the cytoplasm?

Answer 34

• Water
• Electrolytes (Na+,P, Mg2+, Ca2+)
• Enzymes (e.g. protein kinase A)
• tRNA & amino acids)
• Sugars
• Phosphates
• Vitamins
• Cellular waste

Question 35

Insoluble things in the cytoplasm?

Answer 35

• Glycogen (Liver and muscle cells)
• Lipid droplets (adipocytes, hepatocytes undergoing fatty change)
• Pigment (e.g. hemosiderin (iron))

Question 36

Pathologic inclusions in the cytoplasm?

Answer 36

• Cytomegalovirus (owl’s eye inclusions)
• Rabies virus (Negri bodies)
• Herpes virus (Cowdry (type A inclusions) bodies)

Question 37

Cytoplasmic inclusions in neurodegenerative diseases?

Answer 37

-Alzheimer disease (Neurofibrillary tangles from Tau proteins)
Parkinson disease (Lewy bodies)

Question 38

Lysosomal storage disorders?

Answer 38

• Gaucher
• Niemann-Pick
• Tay-Sachs

Question 39

Mucopolysaccharidoses types?

Answer 39

• Hurler

- Hunter

Question 40

Incluson (I) cell disease?

Answer 40

Lysosomal enzymes does not get the Mannose-6-Phosphate address tag which they need to get to the lysosome (because of deficiency in phosphotransferase). Result: Lysosome fills up with undigested junk

Question 41

Chediak-Higashi syndrome

Answer 41

Immunodeficiency syndrome. Lysosomes in phagocytes are defective.
Mutation in the lysosomal trafficking regulator gene (LYST). Results in recurrent pyogenic infections, partial albinism and peripheral neuropathy