Question

how is adp converted to atp?
by the addition of one adenosine molecule
by the addition of one phosphate group
by the removal of one adenosine molecule
by the removal of one phosphate group

Explanation:

ADP (adenosine diphosphate) has two phosphate groups. ATP (adenosine tri - phosphate) has three phosphate groups. So, ADP is converted to ATP by the addition of one phosphate group. Adenosine molecule is not added or removed in this conversion. Removing a phosphate group from ADP would not form ATP.

Answer:

by the addition of one phosphate group