Final answer:
If step 4 of the citric acid cycle occurred near equilibrium, it would not be a control point and would respond passively to substrate and product concentrations, potentially leading to less efficient regulation and cellular energy production.
Step-by-step explanation:
If step 4 of the citric acid cycle occurred near equilibrium rather than far from it, one likely consequence is that this step would lose its ability to be a control point for the cycle. Steps that occur far from equilibrium generally have a large negative ΔG and are often regulated and irreversible. These steps dictate the pace of the cycle and can be likened to a 'valve' controlling the flow of metabolic intermediates. When such reactions occur near equilibrium, they do not exhibit a large change in free energy, thus they are more reversible and can easily proceed in either direction depending on the concentrations of reactants and products. This would mean that the reaction is less likely to be a point of regulation and control.
An implication of this change is that the reaction would then respond passively to the concentrations of its substrates and products rather than being actively regulated by the cell's metabolic needs. As a consequence, the regulation of the citric acid cycle as a whole might become less efficient, leading to less optimal cellular energy production. In this case, the reaction itself would not necessarily need to be coupled to ATP hydrolysis because ATP coupling is usually characteristic of reactions that need to be driven in a particular direction despite an unfavorable equilibrium position. However, the overall production of ATP and other related metabolic processes could be adversely impacted due to the potential dysregulation of the cycle's flux.