Blood is a bodily fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells. The cellular component of the blood responsible for blood clotting are the platelets. The blood clotting mechanism involves many substances like blood platelets, prothrombin, thromboplastin, Ca++, fibrinogen, vitamin K, etc.
Thromboplastin for blood clotting is secreted by platelets. In the presence of calcium, thromboplastin acts on protein prothrombin and forms a proteolytic enzyme called thrombin. Vitamin K is essential for formation of prothrombin in liver. Thrombin acts on a soluble protein fibrinogen and changes it into insoluble fibrin. Fibrin undergoes rapid polymerisation to form long fibres. The fibres form a network over the damaged wall of blood vessel and exposed part of the skin. It traps blood cells and forms a jelly like mass called blood clot. The clot contracts and solidifies. A liquid called serum is expelled.
Thus, the protein involved in coagulation provides the activation for the final step in clotting is the <u>thrombin.</u>
depth of water ranges from 0ft below the surface along major rivers and streams to a maximum estimated at more than 1200 ft below land surface on the southern slops oflarch mountain
well according to my memory and one of the save the earth communities, the great white shark is almost extinct cause of pollution, and mainly poachers, lots of poachers for soup made of shark fins.
they would cut off the fin then throw the dead shark back in the ocean.
Cholestrol streghtens the cell memebrane. Its STRUCTURE gets fixed in the cell membrane and then performs its FUNCTIONS that is to strengthen the cell membrane
