Chlorophyll

Chlorophyll is a green electromagnetic spectrum, hence the green color of chlorophyll-containing tissues like plant leaves.^[1] The ideal spectrum of light is between 400 and 700 nanometers.

Chlorophyll and photosynthesis

Chlorophyll is vital for methanol), these chlorophyll pigments can be separated in a simple paper chromatography experiment, and, based on the number of polar groups between chlorophyll a and chlorophyll b, will chemically separate out on the paper. The function of the reaction center chlorophyll is to use the energy absorbed by and transferred to it from the other chlorophyll pigments in the photosystems to undergo a charge separation, a specific reductant used to reduce CO₂ into sugars as well as for other biosynthetic reductions.

Reaction center chlorophyll-protein complexes are capable of directly absorbing light and performing charge separation events without other chlorophyll pigments, but the absorption cross section (the likelihood of absorbing a photon under a given light intensity) is small. Thus, the remaining chlorophylls in the photosystem and antenna pigment protein complexes associated with the photosystems all cooperatively absorb and funnel light energy to the reaction center. Besides chlorophyll a, there are other pigments, called accessory pigments, which occur in these pigment-protein antenna complexes.

Chemical structure

Chlorophyll is a chlorin pigment, which is structurally similar to and produced through the same metabolic pathway as other Ian Fleming,^[4] and in 1990 Woodward and co-authors published an updated synthesis.^[5]

The different structures of chlorophyll are summarized below:

When leaves degreen in the process of plant senescence chlorophyll is converted a group of colorless tetrapyrroles known as nonfluorescent chlorophyll catabolites (NCC's) with the general structure:

These compounds have also been identified in several ripening fruits.^[6]

Spectrophotometry

Measurement of the absorption of light is complicated by the solvent used to extract it from plant material, which affects the values obtained,

• In diethylether, chlorophyll a has approximate absorbance maxima of 430 nm and 662 nm, while chlorophyll b has approximate maxima of 453 nm and 642 nm.^[7]
• The absorption peaks of Chlorophyll a are at 665 nm and 465 nm. Chlorophyll a fluoresces at 673 nm. The peak molar absorption coefficient of chlorophyll a exceeds 10⁵ M⁻¹ cm⁻¹, which is among the highest for organic compounds.

Chlorosis

Main article: Chlorosis

Chlorosis is a condition in which leaves produce insufficient chlorophyll, turning them yellow. Chlorosis can be caused by lack of nitrogen.

See also

• bacteriochlorophyll
• chlorophyllin, a semi-synthetic derivative of chlorophyll
• Grow light

References