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.
require heat to be added or they liberate heat. The RATE of heat generated (or consumed) is dependant on the rate of the reaction. And most reaction rates are temperature dependant. For that matter, most reactions, especially organic ones, yield different products at different temperatures. So good temperature control is critical to prevent runaway reactions or poor yields and temperature control is dependant on reaction rate.