Final answer:
Work in a chemical system requires an input of free energy for endergonic reactions, overcoming the activation energy barrier to proceed. This constant energy input maintains the organization, growth, and reproduction in living systems.
Step-by-step explanation:
To perform work in a chemical system, such as in biological systems, there must be energy transformations. When considering thermodynamics in chemical reactions, work is associated with energy changes. The question refers to endergonic reactions, which require an input of free energy as they do not occur spontaneously. These endergonic processes need energy for the system to proceed with its chemical transformations, increasing the system's enthalpy (∆Hrxn).
Both endergonic and exergonic reactions need to overcome an initial activation energy barrier. This input of energy allows the system to reach the transition state necessary for the reaction to proceed. Whether a reaction is endergonic or exergonic, all biological systems require a constant input of free energy to maintain organization, grow, and reproduce, as encapsulated in the laws of thermodynamics.
For example, in the case of synthesizing a sugar molecule by bonding with a phosphate group, the reaction would be endergonic. It would require an input of free energy from the surroundings because the process leads to a net absorption of energy.