Paired reactions in which one molecule is oxidised while another is reduced are called:

1. Removing an electron from a molecule oxidises it. 2. That electron does not stay unbonded; it shifts to a second compound, reducing it. 3. Because oxidation and reduction usually occur together, these pairs of reactions are called oxidation reduction reactions, or redox reactions. 4. A compound that reduces another is a reducing agent, and one that oxidises another is an oxidizing agent. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 7 'Cellular Respiration', sections 7.1-7.7_