Streptokinase is an enzyme (a protease) produced by the bacterium Streptococcus. After modification by genetic engineering, it is used as a "clot buster" to remove blood clots from the blood vessels of patients who have had a myocardial infarction (heart attack). Memory hook: "Strepto-KINASE breaks the clot" — Streptococcus makes the enzyme that dissolves clots, so a patient's blood can flow again.
Streptococcus (bacterium) produces the enzyme streptokinase, which after modification by genetic engineering acts as a clot buster to dissolve clots after a heart attack (myocardial infarction).
Your doubts, answered
Is streptokinase a bacterium or an enzyme?
Streptokinase is an enzyme, not a bacterium. It is a bioactive molecule produced BY the bacterium Streptococcus. Students confuse the two because the names sound similar. Remember: Streptococcus = the microbe (producer); streptokinase = the product (the clot-dissolving enzyme).
Which microbe produces streptokinase?
The bacterium Streptococcus produces streptokinase. In NEET match-the-column questions this exact pairing is tested again and again: Streptococcus sp. is paired with streptokinase. Do not confuse it with Trichoderma polysporum (cyclosporin A) or Monascus purpureus (statins).
What is the difference between streptokinase and streptomycin?
Both start with 'strepto' but are very different. Streptokinase is an enzyme (clot buster) from Streptococcus. Streptomycin is an antibiotic made by the actinomycete Streptomyces. Different microbe, different job: streptokinase dissolves clots, streptomycin kills or stops bacteria.
Why is streptokinase 'modified by genetic engineering'?
NCERT specifically says streptokinase is 'modified by genetic engineering' before medical use. Genetic engineering improves the molecule so it works safely and effectively as a clot buster in humans. NEET has directly used the phrase 'modified by genetic engineering', so keep that wording in mind.
What is myocardial infarction and how does streptokinase help?
Myocardial infarction means a heart attack, caused when a clot blocks blood flow in the vessels supplying the heart. Streptokinase acts as a clot buster: it dissolves the clot, restores blood flow, and helps the patient. This 'clot buster after heart attack' link is the most tested fact.
⚠️ The NEET trap ✗ Streptokinase is a microbe/bacterium used to treat liver disease or produce curd. ✓ Streptokinase is an ENZYME produced by the bacterium Streptococcus; it is a clot buster that removes clots from blood vessels after a heart attack (myocardial infarction) — not for curd, ethanol, or liver disease. 🧠 NTA swaps the producer with the product, or gives a wrong use (liver/curd/ethanol). Lock: Streptococcus makes streptokinase, and its ONLY job in NCERT is dissolving clots.
Real NEET questions
NEET 2025
Streptokinase produced by bacterium Streptococcus is used for
A · Liver disease treatment
B · Removing clots from blood vessels ✓
C · Curd production
D · Ethanol production
Solution: Streptokinase, produced by the bacterium Streptococcus and modified by genetic engineering, is a 'clot buster' used to remove clots from the blood vessels of patients who have had a myocardial infarction. It is not used for curd, ethanol, or liver disease.
ReNEET 2026
Which of the following is used as a clot buster?
A · Streptokinase ✓
B · Penicillin
C · Cyclosporin A
D · Statins
Solution: Streptokinase, from Streptococcus and modified by genetic engineering, dissolves clots after a heart attack. Cyclosporin A is an immunosuppressant, statins lower cholesterol, and penicillin is an antibiotic.
NEET 2024
Match List I with List II. A. Clostridium butylicum – I. Ethanol; B. Saccharomyces cerevisiae – II. Streptokinase; C. Trichoderma polysporum – III. Butyric acid; D. Streptococcus sp. – IV. Cyclosporin-A
