Question

The amount of energy given by one mole of ATP is –
A. 7.3 kcal
B. 721 kcal
C. 7600 kcal
D. 1000 kcal

Answer 1

Hint:ATP is the energy currency of the cell. ATP stands for Adenosine Triphosphate. It contains high energy bonds that break to produce energy.

Complete answer: ATP hydrolysis is the catabolic reaction by which chemical energy stored in the high-energy phosphoanhydride bonds in adenosine triphosphate (ATP) is released by the splitting of these bonds, as in muscles, by producing work in the form of mechanical energy. The product of this breakdown is adenosine diphosphate (ADP) and inorganic phosphate, orthophosphate (Pi). ADP can further be hydrolyzed to give energy, adenosine monophosphate (AMP), and another orthophosphate (Pi). ATP hydrolysis is the final step for the energy production from food or sunlight for useful work such as muscle contraction, the establishment of electrochemical gradients across membranes, and biosynthetic processes necessary to maintain life.
The hydrolysis of one ATP mole releases 7.3 kcal of energy (∆G = −7.3 kcal/mol of energy).

So, the answer is option A.

Additional information
The ATP molecule carries energy within cells. It is the main energy currency of the cell and is an end product of the processes of photophosphorylation, cellular respiration, and fermentation. All living beings use ATP. In addition to being an energy source, it is also used in signal transduction pathways for cellular communication and is incorporated into deoxyribonucleic acid (DNA) during DNA synthesis. It is made up of one molecule of adenosine. Adenosine is made up of adenine and ribose sugar. In addition to adenosine, there are three phosphate groups. It is soluble in water and has a high energy content by virtue of its two phosphoanhydride bonds connecting the three phosphate groups. These phosphoanhydride bonds are high energy bonds, which, when broken, release high amounts of energy.

Note: The energy of the ATP molecule is harnessed by the process of oxidative phosphorylation. There, the high-energy bonds break with the help of enzymes. The energy is used for various metabolic processes.