The cellular processes that depend on the energy from ATP are intracellular signalling, DNA and RNA synthesis, transportation across cell membranes and assembly of the cytoskeleton. Breakdown of ATP into ADP is the major source of energy for cells.
Assembly of the cytoskeleton occurs when ATP is used to assemble smaller molecules into macro molecules. ATP is necessary for transportation of molecules across cell membranes because it is needed to transport vesicles containing these molecules to the cell membrane. Intracellular signalling requires ATP in order to activate kinase molecules to move the signal throughout the interior of a cell. DNA and RNA synthesis uses the energy from removing two phosphate groups from ATP when incorporating it into the nucleic acid.