Final answer:
Photoautotrophs, such as plants, algae, and cyanobacteria, convert light energy into chemical energy through photosynthesis, providing an energy source for all members of an ecosystem.
Step-by-step explanation:
The type of organism responsible for converting light energy into chemical energy that can be used by all members of an ecosystem is known as a photoautotroph. Examples of such organisms include plants, algae, and a group of bacteria called cyanobacteria. These organisms perform photosynthesis, using sunlight to produce organic molecules like glucose, which serves as an energy source for themselves as well as for other organisms that are unable to produce their own food, known as heterotrophs.