What does ADP mean in biology?

In Biology, ADP stands for adenosine diphosphate, a nucleotide that plays a crucial role in cellular energy transfer. It consists of adenine, ribose, and two phosphate groups. ADP is formed when ATP (adenosine triphosphate) loses one phosphate group during energy release for cellular processes. It can be converted back to ATP through phosphorylation, allowing cells to regenerate their energy supply.