Accessory pigment other accessory pigments is sometimes referred to as a "pigment bed". The different chlorophyll and non-chlorophyll pigments associated with the photosystems all have different absorption spectra, either because the spectra of the different chlorophyll pigments are modified by their local protein environment or because the accessory pigments have intrinsic structural differences. The result is that, in vivo, a composite absorption spectrum of all these pigments is broadened and flattened such that a wider range of visible and infrared radiation is absorbed by plants and algae. Most photosynthetic organisms do not absorb green light well, thus most remaining light under leaf
Carbon fixation in the chloroplasts of plants and algae, and in the cyanobacteria. It also fixes carbon in the anoxygenic photosynthetic in one type of proteobacteria called purple bacteria, and in some non-phototrophic proteobacteria. In photosynthesis, energy from sunlight drives the carbon fixation pathway. "Oxygenic" photosynthesis is used by the primary producers—plants, algae, and cyanobacteria. They contain the pigment chlorophyll, and use the Calvin cycle to fix carbon autotrophically. The process works like this: In the first step, water is dissociated into electrons, protons, and free oxygen. This allows the use of water, one of the most abundant substances on Earth, as