[PDF] Evolution of photosynthesis: time-independent structure of the cytochrome b6f complex. | Semantic Scholar (2024)

FAQs

What does cytochrome b6f do in photosynthesis? ›

The cytochrome b6f complex provides the electronic connection between the photosystem I and photosystem II reaction centers of oxygenic photosynthesis and generates a transmembrane electrochemical proton gradient for adenosine triphosphate synthesis.

The cytochrome b₆f complex is the photosynthetic electron transport mediator between PSII and PSI transferring electrons from water to NADP⁺.

The cytochrome b6f complex (Cyt b6f), which is reduced from the reducing side of PS II by plastoquinone (PQ) and gives up its electrons to plastocyanin, is found between grana disks and the stromal thylakoid. From: Physiology of Woody Plants (Second Edition), 1997.

In photosynthesis, the cytochrome b₆f complex functions to mediate the transfer of electrons and of energy between the two photosynthetic reaction center complexes, Photosystem II and Photosystem I, while transferring protons from the chloroplast stroma across the thylakoid membrane into the lumen.

The cytochrome b₆ f (cytb₆ f ) complex has a central role in oxygenic photosynthesis, linking electron transfer between photosystems I and II and converting solar energy into a transmembrane proton gradient for ATP synthesis^1-3.

The Cyt b₆/f complex has a unique role in chloroplast electron transport, as it can act in both linear electron transport (production of ATP and NADPH) and cyclic electron transport (ATP generation only).

What is the function of the b6-f complex? The b6-f complex receives electrons from PQ and passes them to plastocyanin (PC). This provides energy for the b6-f complex to pump protons into the thylakoid.

A cytochrome complex plays a key part in electron transport associated with the membranes of the thylakoids in the process of photosynthesis. It accepts electrons from Photosystem II through plastoquinone and contributes to proton transport across the membrane.

The Cyt b ₆ f complex stands at the crossroad of photosynthetic electron transport pathways, providing connectivity between Photosystem (PSI) and Photosysten II (PSII) and pumping protons across the membrane into the thylakoid lumen.

Structure-function studies of the cytochrome b₆f complex, the central hetero-oligomeric membrane protein complex in the electron transport chain of oxygenic photosynthesis, which formed the basis for a high-resolution (2.5 Å) crystallographic solution of the complex, are described.

Is cytochrome b6f an enzyme? ›

The cytochrome b(6)f complex is an obligatory electron transfer and proton-translocating enzyme in all oxygenic photosynthesis.

At left are shown the protein subunits of the integral membrane cytochrome b₆f complex of the cyanobacterium, Mastigocladus laminosus (Kurisu, et al., 2003), oriented with the stroma at top and lumen at bottom.

The excited electrons move to the cytochrome complex. Some of the energy from the electrons is used by the cytochrome complex to transport additional protons into the lumen. The second electron carrier, a protein inside the lumen, receives the electrons and passes them to photosystem I.

Abstract. The cytochrome b(6)f complex is an obligatory electron transfer and proton-translocating enzyme in all oxygenic photosynthesis.

The chloroplast cytochrome bf complex is an intrinsic multisubunit protein from the thylakoid membrane consisting of four polypeptides: cytochrome f, a two heme containing cytochrome b 6, the Rieske iron-sulfur protein, and a 17 kD polypeptide of undefined function.

Role of cytochrome P450 enzyme in plants. Plant hormone metabolism is also regulated by cytochrome P450 enzymes that control cell division and cell expansion, vascular differentiation, fruit growth, root development, and flower formation.