Question

Which one of the following is known as the energy currency of a cell?
A. Adenosine diphosphate
B. Adenosine triphosphate
C. Pyruvate
D. Glucose

Answer 1

Hint: The direct formation of ATP in a metabolic pathway is known as oxidative phosphorylation. The ATP formed as a result of the transfer of electrons. The electrons transfer from NADH to ${FAD}{H}_{2}$ and then to ${O}_{2}$ through a series of electron carriers.

Complete answer:
ATP is an Adenosine triphosphate molecule and is known as an energy-rich molecule. It can store and transport chemical energy in the cells. The ATP molecules play an essential role in nucleic acid synthesis.

Fats produce the most ATP per gram. This is because the fats contain the most reduced form of carbons. It produces twice as much energy as compared to the oxidation of carbohydrates.

ATP hydrolysis is a reaction in which water is used. The reaction of ATP hydrolysis is: ${ATP + }{H}_{2}{O} \to {ATP + }{P}_{i}$

In this reaction, for every molecule of ATP that is hydrolyzed, a mole of ATP is formed through the condensation of ADP and inorganic phosphate. Therefore, there is no net production of water molecules because there is no net charge present on the ATP molecule.

Hence, the correct answer is option (B).

Note: Respiration is important for all living beings present on the earth. This is done with the help of the respiratory system. The respiratory system helps humans to respire in order to produce energy in the form of ATP. The energy is later used to do various works. The glycolysis and the citric acid cycle are the two cellular respiration that makes ATP by using substrate-level phosphorylation. It is a process in which ATP is formed by adding a phosphate group to ADP physically. This process occurs in the cytoplasm.