biochem

Question 1

quinolones MOA

Answer 1

inhibits topoisomerase II (DNA gyrase) which inhibits DNA replication

Question 2

Rifampin MOA

Answer 2

inhibits RNA polymerase which inhibits transcription

Question 3

alpha-amanitin MOA

Answer 3

toxic substance in mushrooms that inhibits RNA Pol 2

Question 4

Chloramphenicol MA

Answer 4

Peptidyl transferase, preventing peptide bond formation

Question 5

Clindamycin MOA

Answer 5

Binds 50S large subunit, preventing translocation of ribosome

Question 6

Macrolides MOA

Answer 6

Binds 50S large subunit, preventing translocation of ribosome

Question 7

list macrolides

Answer 7

erythromycin, azithromycin

Question 8

aminoglycosides MOA

Answer 8

Binds 30S small subunit, preventing initiation of translation

Question 9

list aminoglycosides

Answer 9

Gentamicin, neomycin, and tobramycin

Question 10

Tetracycline MOA

Answer 10

Binds 30S small subunit, preventing codon-anticodon pairing

Question 11

mebendazole/thiabendazole MOA

Answer 11

inhibit microtubule synthesis in parasites

Question 12

actinomycin D MOA

Answer 12

inhibits eukaryotic and prokaryotic transcription

Question 13

cause of SCID

Answer 13

adenosine deaminase deficiency- buildup of ATP and dATP prevents DNA synthesis

Question 14

Cause/ Sx of Lesch Nyhan syndrome

Answer 14

Defective purine salvage to to absent hypoxanthine-guanine phosphoribosyl transferase (which converts hypoxanthine to IMP and guanine to GMP). HGPRT: hyperuricemia, gout, pissed off (aggression, self mutilation), retardation, dystonia

Question 15

xeroderma pigmentosum genetic defect

Answer 15

defective nucleotide excision repair of pyrimidine dimers

Question 16

Hereditary non-polyposis colorectal cancer genetic defect

Answer 16

mismatch repair

Question 17

ataxia telangiectasia gene defect

Answer 17

non-homologous end joining

Question 18

inclusion dz- cause and Sx

Answer 18

inherited lysosomal storage disease (aka I cell disease). Defect in phosphotransferase > failure of golgi to phosphorylate mannose residues on glycoproteins > proteins are secreted extracellularly rather than delivered to lysosomes. Results in coarse facial features, clouded corneas, restricted joint movemnt, high plasma lysosomal enzyme levels. fatal in childhood

Question 19

drugs that act on microtubules

Answer 19

“microtubules get constructed very poorly”- Mebendazole (anti-helminthes), griseofulvin (anti fungal), colchicine (anti gout), vincristine/vinblastine (anti cancer), paclitaxel (anti cancer)

Question 20

Kartagener syndrome cause and sx

Answer 20

Immotile cilia due to dynein arm defect- results in male and female infertility due to immotile sperm and dysfunctional fallopian tube cilia. Also, bronchiectasis, recurrent sinusitis and situs inversus

Question 21

list stains for intermediate filaments in CT, muscle, epithelial cells, neuroglia and neurons

Answer 21

Vimentin (CT), Desmin (muscle), cytokeratin (epithelial), GFAP (neuroglia), and neurofilaments (neurons)

Question 22

cardiac glycosides- list, and MOA

Answer 22

digoxin and digitoxin- inhibit Na/K pump leading to elevated intracellular Na and inhibition o Na/Ca exchanger > elevated intracellular Ca leads to increased cardiac contractility

Question 23

Osteogenesis imperfecta cause and Sx

Answer 23

decreased production of otherwise normal type I collagen due to problems forming triple helix (skin, bone, tendons). Fractures, blue sclera (translucent CT), hearing loss, lack of dentin in teeth

Question 24

Ehlers Danlos- cause and Sx

Answer 24

hypermobility: decreased collagen type 1 (bone, skin, tendons). Vascular type: decreased collagen type 3 (blood vessels). Hyperextensible skin, easy bruising, berry and aortic aneurysms, organ rupture

Question 25

Goodpasture cause

Answer 25

Abs against collagen type IV in basement membrane

Question 26

Scurvy- what causes it

Answer 26

deficiency in Vit C leads to inability to hydroxylate proline and lysine, so collagen is weak

Question 27

Menkes disease- cause and Sx

Answer 27

CT dz caused by impaired copper absorption and transport, leads to decreased activity of lysyl oxidase (Cu is cofactor). Results in brittle, kinky hair, growth retardation and hypotonia

Question 28

Marfan syndrome cause

Answer 28

defect in fibrillin, a glycoprotein that forms a sheath around elastin

Question 29

emphysema cause

Answer 29

alpha 1 antitrypsin deficiency- results in excess elastase activity

Question 30

Southern vs Northern vs Western blots

Answer 30

SNW DRP: southern is DNA, Norhtern is RNA, western is protein