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.
This requires energy, and one way of providing this is from the oxidation of glucose which is an exergonic reaction. There are two reasons why energy from the oxidation of glucose is not used directly to drive chemical reactions in the cell: the hydrolysis of ATP releases small amounts of energy compared to the oxidation of glucose, and in a controlled way.