The chemical equation for respiration of a molecule of glucose is: C6H12O6 + 6O2 -> 6CO2 + 6 H2O. This is the same reaction as when a marshmallow catches fire and burns. In this oxidation-reduction reaction, which molecule(s) is(are) reduced?

Oxidation reaction is defined as the reaction in which an atom looses its electrons.or it can also be understood by saying increase in number of oxygen atoms and decrease in number of hydrogen atom.

Reduction reaction is defined as the reaction in which an atom gains electrons. or it can also be understood by saying decrease in number of oxygen atoms and increase in number of hydrogen atom.

[tex] C_6H_{12}O_6 + 6O_2\rightarrow 6CO_2 + 6 H_2O[/tex]

In the given reaction ,carbon in glucose molecule is going under oxidation as number of oxygen atom per carbon atom is increasing.

And oxygen gas molecule is going under reduction as oxygen atom from [tex]O_2[/tex] gets attached to two hydrogen atoms.