Photosynthesis, which literally means « synthesis [of organic matter] by light », is the trapping of light energy from the sun and its storage as organic matter (especially carbohydrates). In doing so, plants and photosynthetic bacteria produce their own components from solar energy. (They are said to be autotrophic.). In plants and algae, photosynthesis takes place in the green parts, in particular the leaves; indeed, their cells contain small photosynthetic organelles, chloroplasts, which themselves contain chlorophyll, a green pigment that captures light energy. In plants that are not green – for example, plants with purple leaves – the process and location are the same: the chlorophyll is simply masked by pigments of other colours.