Example is conversion of NAD+ to NADH+ is an example of reduced in metabolism.
Step-by-step explanation:
Oxidation and reduction or redox reaction means transfer of electron from one atom to another in a compound.
In photosynthesis and respiration redox reaction are seen.
The substance that gain the electrons in metabolic reaction is said to be reduced.
In respiration process oxygen is being reduced. The NAD+ accepts hydrogen ion and 2 e- to become NADH+H+. These are electron carriers.
The reactions can be seen in glycolysis, Kreb's cycle.