1- ATP is an abbreviation for adenosine triphosphate..
2- ATP is a complex nanomachine that serves as the primary energy currency of the cell. ATP is the most widely distributed high-energy compound within the human body. This molecule is used to build complex molecules, contract muscles, generate electricity in nerves, and light fireflies. All fuel sources of Nature, all foodstuffs of living things, produce ATP, which in turn powers virtually every activity of the cell and organism.
The Function of ATP
ATP is used for many cell functions including:
1- Transport work moving substances across cell membranes.
2- Mechanical work, supplying the energy needed for muscle contraction.
3- 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.
4- A major role of ATP is in chemical work, supplying the needed energy to synthesize the multi-thousands of types of macromolecules that the cell needs to exist.
5- ATP is also used as an on-off switch both to control chemical reactions and to send messages.
Hope this helps =]