[Campbell Biology P.196] The text states that spontaneous changes can be 'harnessed by the c... | Practice Question

The text states that spontaneous changes can be 'harnessed by the cell to perform work.' Based on the understanding of spontaneous reactions, what is their primary characteristic that makes them useful for cellular work?

  • A: They absorb energy from the surroundings, increasing the cell's energy.
  • B: They lead to an increase in the system's order, promoting complex structures.
  • C: They occur rapidly, thus speeding up metabolic processes.
  • D: They decrease the system's free energy, releasing energy that can be coupled to do work.

Explanation

Spontaneous reactions are defined by a negative ΔG, meaning they release free energy. This released free energy can then be 'harnessed' or coupled with non-spontaneous endergonic reactions to drive cellular work, such as ATP synthesis or active transport.