Complete the following sentence -
ADP+Pi`to`ATP is an_________reaction, ATP`to`ADP+Pi is an_______reaction, and the conversion of ADP+Pi to ATP__________energy.

Options

A. Exergonic, endergonic, releases
B. Exergonic, endergonic, requires
C. Endergonic, exergonic, requires
D. Exergonic, endergonic does not involve

Answer

To complete the sentence, we need to understand the types of reactions involved in the conversion of ADP and inorganic phosphate (Pi) to ATP, and the reverse reaction.

1. **ADP + Pi to ATP**: This reaction involves the synthesis of ATP from ADP and inorganic phosphate. This process requires energy input, which is characteristic of an **endergonic reaction**. Therefore, we fill in the first blank with "endergonic".

2. **ATP to ADP + Pi**: This reaction is the breakdown of ATP into ADP and inorganic phosphate, which releases energy. This is characteristic of an **exergonic reaction**. Thus, we fill in the second blank with "exergonic".

3. **The conversion of ADP + Pi to ATP requires energy**: Since the first reaction (ADP + Pi to ATP) is endergonic, it indicates that energy is needed for this conversion. Therefore, we fill in the third blank with "requires".

Putting it all together, the completed sentence reads:
"ADP + Pi to ATP is an **endergonic** reaction, ATP to ADP + Pi is an **exergonic** reaction, and the conversion of ADP + Pi to ATP **requires** energy."