What is the primary characteristic of all reactions in biochemistry?

In biochemistry, one primary characteristic of all reactions is that they have a specific ΔG, which represents the change in free energy during a reaction. This value indicates whether a reaction is energetically favorable or not. A negative ΔG signifies that the reaction can occur spontaneously and releases energy, while a positive ΔG indicates that energy must be input for the reaction to proceed.

The significance of ΔG is rooted in the principles of thermodynamics as applied to biological systems. This concept is crucial for understanding metabolic pathways and how cells convert energy from nutrients to sustain life. Hence, this characteristic serves as a fundamental criterion for assessing the likelihood of a biochemical reaction occurring under given conditions.

While temperature can influence biochemical reactions, and catalysts may facilitate them, the defining trait across all reactions is indeed the specific ΔG, as it fundamentally determines the feasibility and directionality of the reaction itself.