A cell model is shown. Students were instructed to review the types and number of structures that are present in this cell model. Which three cell types could be represented by the model?

Water has a solvent capacity in wich happens all the metabolic reactions

Carbohydrates are used as a source of quick energy, because it´s used a very small amount of ATP to degrade carbohydrates compare to the lipids that need more ATP to be degraded.   In addition to that, the carbohydrates are easly found in nature, easier than lipids.  They are at the base of the trophic chain, present in the plant, fruits and vegetables.