If you have not already done so, download Avogadro for free and watch the tutorials if necessary.
Import with Avogadro the adenosine molecule (sequence Fileà importà Fetch by chemical name), the glycoside forming ADP and ATP, composed by one adenine molecule and one of ribose.
Optimize the geometry so you can see all the atoms in the molecule. Referring to the following structure, insert two phosphate groups into the adenosine molecule in order to build the correct ADP molecule.
Then add the third phosphate group to form the ATP molecule. Study the properties of the three molecules created. What are the biological functions of ATP and ADP molecules?