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
Light-dependent reactions excited state and then is transferred to another molecule in the reaction center. This reaction, called photoinduced charge separation, is the start of the electron flow and is unique because it transforms light energy into chemical forms. The reaction center is in the thylakoid membrane. It transfers light energy to a dimer of chlorophyll pigment molecules near the periplasmic (or thylakoid lumen) side of the membrane. This dimer is called a special pair because of its fundamental role in photosynthesis. This special pair is slightly different in PSI and PSII reaction center. In PSII, it absorbs photons with a wavelength