What type of reactions are characterized by the gain of electrons?

Reduction reactions are characterized by the gain of electrons. In the context of redox (reduction-oxidation) reactions, reduction involves a substance gaining electrons, which reduces its overall charge. This process is essential in various biological systems, such as cellular respiration and photosynthesis, where electron transfer facilitates energy production and storage.

Understanding reduction is also crucial when studying oxidation reactions, which involve the loss of electrons. The interplay between reduction and oxidation is fundamental to many metabolic pathways that organisms rely on for energy and maintaining cellular functions. Therefore, recognizing that reduction specifically means gaining electrons is key to grasping the broader concepts of electron transport and energy transfer in biological systems.