Plants use environmental sources of energy and raw materials for their construction of glucose. In general, plants are autotrophs , or self-nourishing organism. Plants use carbon dioxide, present in the air and dissolved in aquatic habitats, as their carbon source. Plant, some bacteria, and protistans are photoautotrophs. Photoautotrophs produce organic compounds by a metabolic process referred to as photosynthesis .
Photosynthesis is the main route by which carbon and energy enter the web of life.
Before we study the process of photosynthesis, we should first study where this process takes place. In plants, photosynthesis takes place in the chloroplasts. Chloroplasts specialize in producing and briefly storing food. All chloroplasts have two outermost membranes surrounding the stroma, which is a largely fluid interior. The thylakoid, another membrane, weaves through the stroma.