The origin of replication (also called the replication origin) is a particular sequence in a genome at which replication is initiated.
It is the interaction of two or more substances, resulting in chemical changes in them. Chemical reactions take place when some kind of energy is supplied to them. The supplied energy may be in the form of heat, light or mechanical shaking for proper contact between the reactant molecules or electricity.
In all chemical reactions, mass is always conserved... In chemical reactions, atoms rearrenge to form products... During chemical change atoms arrange and form new bonds. The new bonds are form to make the products. Chemical reactions occur when different atoms and molecules combine together and spit apart. For example, if Carbon (C) is burnt in Oxygen (O2) to form Carbon Dioxide, a <b>Chemical Reaction</b> occurs.<br />So, during chemical reactions, new product atoms are not created, and old reactant atoms are not destroyed.