Streptokinase enzyme is used for:

The correct answer is Option (1) → removing clot from blood vessels

Option (1) removing clot from blood vessels — Correct. Streptokinase is a ‘clot buster’. It is given to patients who have had a heart attack.

Option (2) clarifying fruit juices — Incorrect. Bottled fruit juices are clearer than those made at home because they are clarified by the enzymes pectinases and proteases. Streptokinase plays no part in this; it acts on clots in blood vessels.

Option (3) synthesis of cholesterol — Incorrect. Medicine works the other way here. Statins, from the yeast Monascus purpureus, lower blood cholesterol by blocking the enzyme that makes it.

Option (4) removing oily stains — Incorrect. Microbial lipases are the enzymes used in detergent formulations, where they help remove oily stains from laundry. Streptokinase is not used in detergents.

NCERT Extract:
Chemicals, Enzymes and Other Bioactive Molecules – “… Yeast (Saccharomyces cerevisiae) is used for commercial production of ethanol. Microbes are also used for production of enzymes. Lipases are used in detergent formulations and are helpful in removing oily stains from the laundry. You must have noticed that bottled fruit juices bought from the market are clearer as compared to those made at home. This is because the bottled juices are clarified by the use of pectinases and proteases. Streptokinase produced by the bacterium Streptococcus and modified by genetic engineering is used as a ‘clot buster’ for removing clots from the blood vessels of patients who have undergone myocardial infarction leading to heart attack.”