Three groups of drugs are used to reduce the stickiness of platelets, thus preventing platelets from clumping together to form platelet plugs. The anti-platelet drugs are most effective in preventing abnormal blood clots from forming in arteries (as opposed to veins). Aspirin and dipyridamoleâ (Aggrenox).
In order to react, colliding molecules must have a total kinetic energy equal to or greater than some minimum value [Figure 14.13(b)]. The minimum energy required to initiate a chemical reaction is called the activation energy, Ea. The value of Ea varies from reaction to reaction.
Activation energy: a chemical reaction is the difference between the energy of the activated complex and the energy of the reactants. Catalyst: substance that increases the rate of a chemical reaction by reducing the activation energy, but which is left unchanged by the reaction. Entropy: The measure of the disorder of a system, usually denoted by the letter S.