Stemming the flow
Proteins are vital for blood clotting
One of blood’s amazing properties is that it contains a liquid toolkit that starts the repair of blood vessels if they spring a leak. A collection of soluble proteins is activated when tissue is damaged. These proteins unite to make an insoluble complex, which is the beginning of a blood clot.
When you cut yourself, you do not bleed for long. A cascade of reactions is triggered, which leads to the activation of the enzyme thrombin from its precursor protein prothrombin.
Thrombin, in turn, converts the soluble protein fibrinogen into insoluble fibrin, which builds the scaffolding for a clot.
Poisonous snakes often harm their prey by interfering with blood clotting. Snakes produce more than 100 thrombin-like enzymes, which cause blood to coagulate inside the blood vessels.