The synthesis of ATP from ADP and inorganic phosphate is a(n)______ reaction that is coupled to a reaction known as ______. A. Endergonic: Chemiosmosis B. Exergonic; Chemiosmosis C. Chemical; ATP synthase D. Chemiosmotic; ATP synthase
Hint: Chemiosmosis is an important type of diffusion that happens over the plasma membrane. Chemiosmosis takes consideration, into concentration as well as an electrical charge. Hence, chemiosmosis exclusively has to do with the movement of ions across the plasma membrane.
Complete answer: In an endergonic reaction, the change of free energy is positive. This type of reaction consumes energy rather than producing it. Hence, it requires energy from outside to be driven by external forces. ATP or adenosine triphosphate is synthesized by joining of ADP and inorganic phosphate. It is coupled with a process called chemiosmosis. As chemiosmosis provides energy for the ATP synthesis reaction, it is an endergonic reaction. The movement of ions across a membrane-bound structure long an electrochemical gradient is called chemiosmosis. Here, the membrane has to be semi-permeable, such as the cell membrane. The formation of ATP occurs as H+ (hydrogen) ions move across the mitochondrial membrane during cellular respiration or photosynthesis.
So, the correct option is A. Endergonic: Chemiosmosis
Note: In chemistry, an exergonic reaction is a reaction in which change of free energy is negative. It means the reaction releases free energy and does not consume it. As energy is not consumed, the reaction can occur spontaneously, without any force of external factors. ATP synthase is a multi-subunit enzyme responsible for ATP synthesis.