Answer:
ATP is used for many cell functions including moving substances across cell membranes, supplying the energy needed for muscle contraction, supplying the needed energy to synthesize the multi-thousands of types of macromolecules that the cell needs to exist. It supplies energy not only to heart muscle (for blood circulation) and skeletal muscle (such as for gross body movement), but also to the chromosomes and flagella to enable them to carry out their many functions. ATP is also used as an on-off switch both to control chemical reactions and to send messages.