High energy compound is

Adenosine Triphosphate (ATP) i. ATP is the universal currency of energy within the living cells. Structure of ATP is shown in Figure 5.3. ii. The hydrolysis of ATP to ADP (under standard conditions) releases -30.5 kJ/mol or-7.3 kcal/mol (DG0' = - 7.3). The energy in the ATP is used to drive all endergonic (biosynthetic) reactions. The energy efficiency of the cell is comparable to any machine so far invented. ATP captures the chemical energy released by the combustion of nutrients and transfers it to synthetic reactions that require energy. iii. At rest, Na+-K+ -ATPase (see Chapter 2) uses up one-third of all ATP formed. Other energy requiring processes are, biosynthesis of macromolecules, muscle contractions, cellular motion using kinesin, dynein, etc. iv. ATP is continually being hydrolyzed and regenerated. An average person at rest consumes and regenerates ATP at a rate of approximately 3 molecules per second, i.e. about 1.5 kg/ day!Ref: DM Vasudevan Textbook of Medical Biochemistry, 6th edition, page no: 226