What are antibiotics? Describe the discovery of penicillin and explain why antibiotics must be used judiciously.
How to lay out the answer. Follow the frame, then write it in your own words.
1 · Define in one line. Antibiotics are chemicals produced by some microbes that kill or retard the growth of disease-causing microbes.
2 · Discovery. Fleming, working on Staphylococci, saw no growth around a mould in an unwashed plate; the mould Penicillium notatum made penicillin.
3 · Development. Chain and Florey established its full potential; used in World War II; Nobel Prize 1945 to all three.
4 · Production and value. Antibiotics made plague, whooping cough, diphtheria and leprosy treatable. Extra, beyond the textbook: high-yielding strains are grown in fermentors and the antibiotic is purified.
5 · Judicious use (extra points, not listed in your textbook).
Only on prescription; no self-medication.
Complete the course.
Not for viral infections like the common cold.
Misuse selects resistant bacteria.
6 · Link to daily life. Never ask a chemist for antibiotics for a cold or viral fever.
7 · Close in one line. So antibiotics are life-saving only if we use them wisely.
Scoring tip: Name Staphylococci, Penicillium notatum and all three Nobel winners. Then explain resistance in one or two sentences using the idea of selection.
