Biochemical reactions differ from chemical reaction since they generally use enzyme as the catalyst. Additionally, the biochemical reactions follow complex pathways and in general, the balanced equations are not written or they are written for the entire pathways (as a single equation).
For example, For lactate fermentation, the overall reaction is:
Glucose + 2 ADP + 2Pi `<=>` 2Lactate + 2ATP + 2 H2O
this composite reaction is made up of a large number of intermediate reaction steps.
Here is an example of a balanced biochemical reaction:
`0.90866G6P^(2-) + 0.06483HG6P^(-) + 0.02651MgG6P + 0.23634H^(+) + H_(2)O-> `
`Glucose + 0.67349 HPO_(4) ^(2-) + 0.30117 H_(2)PO_(4) ^(-) + 0.02534MgHPO_(4) + 0.00118 Mg^(2+)`
This reaction is generally written as G6P + H2O -> Glucose + HPO4 -
The biochemical reactions are complex because of presence of several intermediate steps, division of electrons between substrate and energy production, generation of intermediate metabolites, etc.
Hence, we typically write balanced biochemical reactions only when needed.
Hope this helps.
Please check the first and the second reactions in the images