What are the differences between ADP and ATP?
Posted August 9, 2022
ADP and ATP are molecules that contain stored chemical energy to be used by the cells. Despite this common function, there are a few notable differences between the two in terms of their physical properties as well as their biochemical roles in the human body.
|Basis for comparison||ADP||ATP|
|Full Name||Adenosine Di Phosphate||Adenosine Tri Phosphate|
|Number of phosphate groups||Contains 2 phosphate groups||Contains 3 terminal phosphate groups|
|Chemical composition||Composed of 1 adenine molecule, a ribose sugar and two phosphate groups||Composed of 1 adenine molecule, a ribose sugar and three phosphate groups|
|Method of generation||Generated as a result of de-phosphorylation of ATP molecule by enzymes known as ATPases||Generated as a result of photophosphorylation, aerobic respiration, and fermentation in biological systems|
|Energy state of molecule||Is the lower-energy molecule of the two because of the absence of the high-energy pyrophosphate bond||Is the higher-energy molecule of the two because of the presence of the pyrophosphate bond- a high-energy bond between the last two phosphates|
|Molar mass||427.201 g/mol||507.18 g/mol|
|Energy releasing mechanism||ADP + H2O → AMP + PPi||ATP + H2O → ADP + Pi|