What does it means when a molecule becomes oxidized? Reduced?

Question

What does it means when a molecule becomes oxidized? Reduced?

Answer 1

Basically reduction is the transfer of one or more electrons to a molecule. Oxidation is the opposite the aqcuisition of one or more electrons from another molecule.

Answer 2

Molecule becomes oxidized when it receives oxygen or donate electron/electrons or donate hydrogen.So, by this it is called reducing agent.In contrast,molecule is reduced when it donate oxygen or accept electron/electrons or accept hydrogen.(It is an oxidising agent).

Answer 3

Oxidation is electron loss and reduction is electron gain (OIL RIG)

EG. In respiration NAD is reduced to NADH.

In photosynthesis NADP is reduced to NADPH.

ATP formation involves redox reactions as electrons are passed from carrier to carrier becoming oxidised and reduced in the process.