This article maybe helpful for you.

https://www.nature.com/articles/s41596-019-0204-0

Dear Irene,

Metabolite network maps of glycolysis and the TCA cycle can be found in every biochemistry textbook book for undergraduate students

As you seem to already have the Mass isotopomer data of different metabolites (obtained from 13C feeding experiments followed by GC-MS), This is the typical workflow you can adopt ahead:

1. Do mass correction to remove the contribution of natural abundances of isotopes (You can use IsoCorr or similar tools- https://academic.oup.com/bioinformatics/article/28/9/1294/312644).

2. The resulting Mass isotopomer distribution data can be used to map metabolism of your cells (see here how we did it Article The Entner-Doudoroff and Nonoxidative Pentose Phosphate Path...

https://www.mdpi.com/2218-1989/8/4/66)

3. You can further define the carbon transition network in INCA or any other 13C MFA software (See tutorial as well as examples that come with the package).

4. Metabolic Modelling/Flux analysis in the platform needs - Substrate Uptake rates, Biomass components efflux rates (which you might have measured or borrowed from literature on your system). Your measured isotopomer data also goes as input while flux analysis. The model predicts isotopomer distribution and compares with your measured and provides the fit as statistically acceptable or not (You may need to play with the model iteratively until you get confidence on the flux values). More reading will help - https://www.nature.com/articles/s12276-018-0060-y and references there off.

Sounds a bit complex, but once you try one can master it.

Best wishes