1. What are antibiotics?
- 1) Anti-ulcer drugs
- 2) Anti-microbial drugs
- 3) Anti-cancer drugs
- 4) Nutrient supplements
Answer: 2)
Explanation: Antibiotics are metabolites having antimicrobial activity. Therefore, they are widely used for curing of human ailments caused by microbes. The first antibiotic discovered was penicillin by Alexender Fleming.
2. Who discovered the first antibiotic?
- 1) Kary Mullis
- 2) Francis Crick
- 3) Louis Pasteur
- 4) Alexander Fleming
Answer: 4)
Explanation: The antibiotic penicillin was discovered by Alexander Fleming in 1929, but its commercial production commenced only during the early 1940s. Fleming was also the first to raise a concern about the potential of bacteria developing resistance due to the exploitation of antibiotics, a problem which poses a major threat to healthcare in this era.
3. How many antibiotics have still been isolated?
- 1) 3000
- 2) 7000
- 3) 2000
- 4) 5000
Answer: 2)
Explanation: Although more than 7,000 antibiotic compounds have been isolated till date, only 100 or so are being used to treat human, animal and plant diseases. The first antibiotic discovered was penicillin by Alexender Fleming.
4. Antibiotics are mainly produced by _______
- 1) Fungi and bacteria
- 2) Fungi
- 3) Algae
- 4) Bacteria
Answer: 1)
Explanation: Antibiotic compounds can be used either in their natural form or in their semi-synthetic derivatives. The semi synthetic derivatives are produced by isolating the antibiotic nucleus and subjecting it to certain chemical modification. Antibiotics are produced by both fungi and bacteria.
5. How inoculum is prepared in the production of antibiotics?
- 1) On suspension
- 2) First on solid media than on liquid media
- 3) On liquid media
- 4) On solid media
Answer: 2)
Explanation: Inoculum development begins on solid media, and then liquid media are used; the media used are specific for inoculum development. Spore suspension is prepared for inoculum. This will be then transferred to the fermenter.
6. Penicillin is active against ________
- 1) All bacteria
- 2) All virus
- 3) Gram-ve bacteria
- 4) Gram +ve bacteria
Answer: 4)
Explanation: First discovered by Alexander Fleming in 1929. Natural penicillin is active against a variety of gram +ve bacteria organisms. They are labile in acids and become inactive when its beta-lactam ring is cleaved by beta-lactamase enzyme.
7. Penicillin inhibits cell wall synthesis.
- 1) Unpredictable
- 2) Incomplete statement
- 3) False
- 4) True
Answer: 4)
Explanation: Penicillin is an inhibitor of cell wall synthesis. They bind to penicillin-binding protein (PBP) present in the cell. This results in peptidoglycan synthesis, leading to death to cell death.
8. Penicillium chrysogenum produce penicillin.
- 1) Unpredictable
- 2) Incomplete statement
- 3) False
- 4) True
Answer: 4)
Explanation: Penicillium chrysogenum or P. Notatum (formerly) is a species of fungus. Common in temperate and subtropical regions. It has rarely caused human disease. It is the source of several β-lactam antibiotics, most significantly penicillin. Other secondary metabolites include roquefortine C, Meleagris, etc.
9. What is the precursor of penicillin?
- 1) L-α aminoadipic acid
- 2) phenylacetic acid
- 3) Isopenicillin N
- 4) Benzylpenicillin
Answer: 2)
Explanation: Benzylpenicillin (Penicillin G) is a narrow spectrum antibiotic used to treat infections caused by some bacteria. It is a natural penicillin antibiotic administered intravenously or intramuscularly. Penicillin G may also be used in cases such as prophylaxis against susceptible organisms.
10. pH required for the production of penicillin will be ________
- 1) 5.0
- 2) 6.5
- 3) 7.5
- 4) 8.0
Answer: 2)
Explanation: The pH should be has to be between 6.4 and 6.8 during the active production phase of penicillin. All the necessary precursors, ammonia, sugar, carbon dioxide, oxygen is controlled, by thorough monitoring of temperature and pH for optimal antibiotic production.
11. The doubling time of Penicillium notatum is ________
- 1) 3 hrs
- 2) 4 hrs
- 3) 5 hrs
- 4) 6 hrs
Answer: 4)
Explanation: Growth phase is of 40 hrs duration with a doubling time of 6 hrs. Oxygen supply becomes critical during this phase due to an increase in viscosity of the medium. Production phase duration is 120 to 180 hrs.
12. How is penicillin stored?
- 1) Sublimation
- 2) Distillation
- 3) Crystallization
- 4) Filtration
Answer: 3)
Explanation: Pure metal salts of penicillin can be safely sterilized by dry heat if desired. Thereafter, the aqueous solution of penicillin is subjected to crystallization. The alkali metal salts of penicillin are extremely soluble in water, and methods therefore known for crystallizing them have employed organic solvents under nearly anhydrous conditions.
13. Streptomycin is _____ antibiotic.
- 1) Medium spectrum
- 2) Narrow and broad spectrum
- 3) Broad spectrum
- 4) Narrow spectrum
Answer: 3)
Explanation: Streptomycin has amino cyclohexanol moiety. It is effective against gram -ve organisms but yet it is broad-spectrum antibiotic. It is used for the treatment of tuberculosis. Its side effect is nephrotoxicity.
14. How is streptomycin recovered?
- 1) Size exclusion chromatography
- 2) Ion exchange chromatography
- 3) Hydrophobic chromatography
- 4) Paper chromatography
Answer: 2)
Explanation: Streptomycin is an antibiotic which is used to treat a number of bacterial infections. It is an extracellular product so they are removed by adsorption to ion exchange columns in chromatography. The period of operation is short and streptomycin sulfate is obtained in a single fraction with an overall yield of approximately 60 percent at a purity of 400 to 600 units per mg.
15. pH range required for streptomycin production is _______
- 1) 9-10
- 2) 4-5
- 3) 5-8
- 4) 7-8
Answer: 4)
Explanation: The optimum temperature for fermentation should be in the range of 25 to 30°C. The optimum pH range should be in the range of 7.0 and 8.0. High rate of streptomycin production occurs in the pH range of 7.6 to 8.0.
