Explain the term 'energy currency'. Which substance acts as energy currency in plants and animals?

Explanation

The term energy currency refers to that molecule which provides energy for cellular acitivities, whenever required. ATP is termed as energy currency because the energy is present in the form of high energy bonds of ATP. Other energy yielding molecules are GTP, CTP, UTP, etc.

The conversion of ATP to ADP yields about 7.3 kcal/ mol of energy. This is the energy source in a variety of bilogical processes occurring in both plants and animals.
Justification for the term 'energy currency' for ATP can be given as
(i) Store small packets of energy as soon as it is available thus, minimising its wastage.
(ii) Can make energy available to a distant location in cell away from where the site it is produced.
(iii) Can carry out heavy work/activity by continuosly supplying large amount of energy through is accumulation at one place.