Cell Bio: Cytoskeleton and Cytoplasm

Question 1

Cytoskeletal filaments from smallest to largest

Answer 1

1. microfilaments
2. intermediate filaments
3. microtubules

Question 2

Two components that make up mictrotubules

Answer 2

Alpha and beta tubulin

Question 3

B tubule is oriented towards + or - end of MT?

Answer 3

+ end, one distal to nucleus

Question 4

Dynein moves which way

Answer 4

retrograde (from + to - ends)

Question 5

Kinesin moves which way

Answer 5

anterograde ( - to + end)

Question 6

Cilia are important in what three places in body

Answer 6

1. respiratory tract
2. paranasal sinuses
3. fallopian tubes

Question 7

What structure links peripheral 9 doublets in the 9+2 arrangement of microtubules in a cilia?

Answer 7

Axonemal dynein (ATPase that causes bending of cilia)

Question 8

What disease results from axonemal dynein arm defect?

Answer 8

Primary ciliary dyskinesis, aka Kartagener’s Syndrome

Question 9

Main 4 issues in Kartagener’s syndrome?

Answer 9

1. bronchiectasis
2. chronic sinusitis
3. infertility
4. situs inversus (50% of cases)
   * bronchiectasis + chronic sinusitis + situs inversus is pretty diagnostic; situs inversus b/c cilia important in organ placement during development

Question 10

What intermediate filament is present in connective tissue ( fibroblasts, leukocytes, endothelium) that can be stained for? What CA can the stain be useful in detecting?

Answer 10

Vimentin–> stains can help ID sarcomas

Question 11

What int. filament is found in muscle cells? Stains can help ID what CA?

Answer 11

Desmin–> myosarcomas (rhabdomyosarcoma, leiomyosarcomas, etc.)

Question 12

What int. filament can be stained for in epithelial cells? What CA?

Answer 12

Cytokeratin–> carcinomas (cancers of epithelial cell origin)

Question 13

What int. filament is found in glial cells? CA stains?

Answer 13

GFAP (glial fibrillary acid proteins)–> astrocytomas (glioblastoma)

Question 14

What int. filament is found in neurons?

Answer 14

Peripherin

Question 15

What int. filament is found specifically in the axons within neurons? CA?

Answer 15

Neurofilaments–> neuroblastomas (in adrenal medulla in kids)

Question 16

*What int. filaments are found in the nuclear envelope and the DNA within?

Answer 16

Laminins (A, B, C types)

Question 17

What two dz can result form mutated laminins?

Answer 17

1. Progeria (early aging of cells, wrinkly skin on 5 y.o.)

2. Muscular dystrophy

Question 18

What structures allow for coordinatd movement of cilia on different cells?

Answer 18

Gap junctions

Question 19

What are 5 drugs/ drug classes that interfere with microtubule function?

Answer 19

1. Vinca alkyloids –> Vincristine, Vinblastine
2. Taxanes –> Paclitaxel, Docetaxel
3. Benzimidazoles –> Mebendazole, Albendazole, Thio-
4. Griseofulvin–> antifungal
5. Colchicine

Question 20

What disease results from impaired microtubule-dependent sorting of endosomal proteins in late multivesicular endosomes?

Answer 20

Chediak-Higashi syndrome–> due to mutation in lysosomal trafficking regulator gene (LYST); recurrent pyogenic infections, partial albinism, peripheral neuropathies

Question 21

3 lysosomal storage dz

Answer 21

1. Gaucher
2. Niemann-Pick
3. Tay-Sachs