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The function of Chl f in photosynthetic reactions is uncertain and the ecological distribution of Chl f remains unknown. Chl f has been shown to support some of the roles in photosynthetic reactions, in both the energy transfer and in the charge separation processes. [4] [5] [6] Chl f is produced from chlorophyllide f by chlorophyll synthase.
Chlorophyll f was announced to be present in cyanobacteria and other oxygenic microorganisms that form stromatolites in 2010; [13] [14] a molecular formula of C 55 H 70 O 6 N 4 Mg and a structure of (2-formyl)-chlorophyll a were deduced based on NMR, optical and mass spectra. [15]
Photosynthetic reaction centre proteins are main protein components of photosynthetic reaction centres (RCs) of bacteria and plants. They are transmembrane proteins embedded in the chloroplast thylakoid or bacterial cell membrane. Plants, algae, and cyanobacteria have one type of PRC for each of its two photosystems.
The reaction begins with the excitation of a pair of chlorophyll molecules similar to those in the bacterial reaction center. Due to the presence of chlorophyll a, as opposed to bacteriochlorophyll, Photosystem II absorbs light at a shorter wavelength. The pair of chlorophyll molecules at the reaction center are often referred to as P680. [1]
Chlorophyll and haem share a common precursor in the form of Protoporphyrin IX, and share the same characteristic closed tetrapyrrole ring structure. In contrast to bilins, haem and chlorophyll carry a metal atom in the center of the ring, iron or magnesium, respectively.
The light-harvesting complex (or antenna complex; LH or LHC) is an array of protein and chlorophyll molecules embedded in the thylakoid membrane of plants and cyanobacteria, which transfer light energy to one chlorophyll a molecule at the reaction center of a photosystem. The antenna pigments are predominantly chlorophyll b, xanthophylls, and ...
The chlorosome is equipped with rod-like BChl c aggregates with protein embedded lipids surrounding it. [12] Chlorosomes are found outside of the membrane which covers the reaction centre. [13] Green sulphur bacteria and some Chloroflexia use ellipsoidal complexes known as the chlorosome to capture light. Their form of bacteriochlorophyll is green.
The cyclic light-dependent reactions occur only when the sole photosystem being used is photosystem I. Photosystem I excites electrons which then cycle from the transport protein, ferredoxin (Fd), to the cytochrome complex, b 6 f, to another transport protein, plastocyanin (Pc), and back to photosystem I. A proton gradient is created across the ...