Chlorophyll b chloroplasts. Chlorophyll b Chlorophyll "b" is a form of chlorophyll. Chlorophyll "b" helps in photosynthesis by absorbing light energy. It is more soluble than chlorophyll "a" in polar solvents because of its carbonyl group. Its color is green, and it primarily absorbs blue light. In land plants, the light-harvesting antennae around photosystem II contain the majority of chlorophyll "b". Hence, in shade-adapted chloroplasts, which have an increased ratio of photosystem II to photosystem I, there is a higher ratio of chlorophyll "b" to chlorophyll "a". This is adaptive, as increasing chlorophyll "b" increases the range of wavelengths absorbed by the
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