other

Question 1

treatment for moderate Type II diabetes

Answer 1

• drugs that stimulate insulin secretion= sulfonylureas

- drugs that improve insulin sensitivity= thiazolidinediones

Question 2

mechanism of action of sulfonylureas

Answer 2

they increase insulin secretion by activating certain membrane channels;

these are the same channels which are activated when glucokinase acts as a sensor of glucose and leads to ATP production, the ATP activating these channels

Question 3

metformin

Answer 3

-first line of treatment for type 2 diabetes
-supressess liver gluconeogenesis
(as, normally insulin lowers PEPCK activity in cells but in diabetes when this inhibition is lifted gluconeogenesis can increase and contribute to hyperglycemia further)

Question 4

Diphtheria toxin

Answer 4

• protein synthesis inhibitor
• catalyses covalent modification of eEF2
• inhibits the eEF2 function of translocation in translation in eukaryotes
• leads to death
• one of the deadliest substances known

Question 5

Ricin

Answer 5

• (protein synthesis inhibitor)
• targets eukaryotes
• depurinates a single adenosine from 28SrRNA
• this inactivates the ribosome and the elongation factors can no longer bind
• it acts catalytically–therefore, one ricin molecule can inactivate 50,000 ribosomes

Question 6

streptomycin

Answer 6

• antibiotic
• binds to 30S ribosomal subunit
• inhibits initiation at high concentrations
• at lower concentrations, causes misreading of mRNA- resulting mutations slow the rate of bacterial growth
• it was the first really effective drug against tuberculosis

Question 7

Tetracycline

Answer 7

• inhibits binding of aminoacyl-tRNA to the 30S subunit

- it is a broad-spectrum antibiotic, also effective against rickettsial organisms,mycoplasmas and certain protozoa

Question 8

Oxazolidines

Answer 8

(e. g. linezolid)
- synthetic antibiotics that are highly resistant against gram-positive bacteria
- they inhibit the formation of the initiation Met tRNA-30S subunit-mRNA complex

Question 9

Chloramphenicol

Answer 9

• antibiotic
• inhibits peptidyl transferase activity of the 50S subunit
• relatively toxic to humans as it affects mitochondrial protein synthesis
• not used as a general anti-bacterial agent; it is used to target typhoid fever and bacterial meningitis

Question 10

Erythromycin

Answer 10

-binds to 50S subunit at the entrance to the peptide exit tunnel and blocks the progression of the nascent peptide
(“molecular constipation”)

Question 11

Actinomycin D

Answer 11

• blocks all RNA synthesis immediately
• binds tightly to dsDNA (by intercalating between neighbouring GC base pairs)
• too toxic for clinical use generally
• its inhibition of growth of rapidly dividing cells makes it an effective therapeutic agent in the treatment of some cancers

Question 12

Rifamycin (rifampicin)

Answer 12

• an antibiotic
• blocks all bacterial RNA synthesis by binding the b-subunit of RNA polymerase
• doesn’t affect eukaryotic transcription significantly
• used in treatment of tuberculosis

Question 13

Camptothecin

Answer 13

topoisomerase I inhibitor drug as anti-cancer

Question 14

etoposide, doxorubicin

Answer 14

Topoisomerase II inhibitors as anti-cancer

Question 15

Ciprofloxacin

Answer 15

Topoisomerase I inhibitor as anti-biotic