The chemical reactants on the left produce on the right
adp+p+energy->

The chemical reactants on the left produce Adenosine triphosphate (ATP) on the right.

Explanation:

Adenosine triphosphate (ATP) can be described as the energy molecule which is used by almost every cell of an organism's body to carry out normal functions of a cell.

Adenosine triphosphate (ATP) is an unstable molecule hence it usually occurs as ADP ( Adenine diphosphate) or AMP (adenine monophosphate). When a phosphate atom attaches to ADP, ATP is produced. The breakdown of ATP releases adenine diphosphate, phosphate along with the release of energy.

The chemical reactants on the left produce ATP on the right.

Explanation:

The energy in the cell is in the form of ATP which means it is the energy currency of the cell.  The hydrolysis of ATP produces ADP, phosphate group and energy. The reaction is reversible and since the produced ATP gets used up quickly the generation of ATP from ADP and phosphate is a an important reaction.

The reaction of hydrolysis is represented as

Since ATP is an energy source mere combination of ADP and phosphate group cannot  produce ATP. The reaction requires input energy.