What is the fundamental difference between the nutritional needs of autotrophic and heterotrophic prokaryotes?

In general, autotrophic organisms are able to produce inorganic carbon molecules, while heterotrophs absorb or ingest carbon molecules to produce energy. Autotrophic prokaryotes, in particular, use carbon dioxide in order to produce organic molecules. On the other hand, heterotrophs consume autotrophs or products produced by autotrophs as energy resources.