1. The correct option is ADENOSINE TRIPHOSPHATE, ATP. ATP is the basic unit of energy transfer in the living cells. ATP is the principal energy source for metabolic functions, in the cells, ATP are consumed by endothermic metabolic reactions and they are produced by exothermic metabolic reactions.
2. To form ATP, A THIRD PHOSPHATE GROUP HAS TO BE ADDED TO ADP. ADP has two phosphate groups while ATP has three phosphate group. ADP is usulally converted to ATP by the addition of a single phosphate group.
3. ADP and ATP work together and the two can be interconverted. ATP can be hydrolysed to ADP and ADP can be converted to ATP by the addition of a single phosphate group. When energy is needed inside a cell, the ATP will split off one of its phosphate group and become ADP. This split off process produce a high qunatity of energy which is then available for the cell to use.
