1. ATP versus ADP ATP is a high-energy molecule. Cells use ATP for functions such as building molecules and moving materials by active transport. ADP is a lower-energy molecule that can be converted into ATP by the addition of a phosphate group.

2. Question:What does “ATP” stand for? Answer:Adenosine Triphosphate Question:What are the components of ATP? Answer:ATP is made up of an adenosine molecule bonded to 3 phosphate groups Question:What is the difference between ATP and ADP? Answer:ATP has 3 phosphate groups, while Adenosine Diphosphate (ADP) only has 2 phosphate groups *Remember: tri=3 di=2

3. The energy carried by ATP is released when the bond between the second and third phosphates is broken. A phosphate group is also released at this time. The energy released from ATP is then used for various cell functions. To convert ADP back to ATP, a phosphate group must be added, along with an input of energy.