Here's the breakdown:

* Photosynthetic bacteria DO obtain energy from light. This is the primary way they generate energy, similar to plants. They use chlorophyll or other pigments to capture light energy.

* Some photosynthetic bacteria CAN use inorganic molecules as electron donors. This is called anoxygenic photosynthesis and it differs from the more familiar oxygenic photosynthesis used by plants and algae.

Here's an example:

* Purple sulfur bacteria use hydrogen sulfide (H₂S) as an electron donor. They oxidize H₂S into sulfur, releasing electrons that flow through an electron transport chain to generate ATP (energy).

Key points:

* Not all photosynthetic bacteria use inorganic molecules as electron donors. Many use water like plants do.

* Anoxygenic photosynthesis doesn't produce oxygen as a byproduct.

Let me know if you'd like to know more about anoxygenic photosynthesis or different types of photosynthetic bacteria!