What are cytochromes and how do they function in photosynthesis?
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.
What is the function of the cytochrome?
Cytochromes are proteins that contain heme as their prosthetic group and whose principal biological function, in the cells of animals, plants, and microorganisms, is electron transport.
Is cytochrome c used in photosynthesis?
It is located in the thylakoid lumen, and functions in photosynthesis in the transfer of reducing equivalents from cytochrome f of the cytochrome b6f complex to Photosystem I (Merchant and Dreyfuss, 1998). There is considerable variation across species in the pI of both cytochrome c6 and plastocyanin.
What is the function of the cytochrome complex in photosynthesis quizlet?
The cytochrome complex transfers protons across the thylakoid membrane and transfers electrons from PS-II to PS-I. The products of the light dependent reaction are used to power the Calvin cycle to produce glucose.
What is the role of cytochromes in the electron transport chain?
Cytochrome c is functionally involved in the electron transport chain of mitochondria. That electron transport is part of the pathway for synthesis of ATP. The role of cytochrome c is to carry electrons from one complex of integral membrane proteins of the inner mitochondrial membrane to another (Fig.
What are cytochromes simple definition?
Definition of cytochrome : any of several intracellular hemoprotein respiratory pigments that are enzymes functioning in electron transport as carriers of electrons.
What is the function of cytochromes in cellular respiration?
Cytochromes are haem-proteins. They act as an electron carriers and are involved in the redox reaction in the living system. They are involved in the electron transport system in the mitochondria.
What is the role of cytochrome in respiration?
Cytochrome c is primarily known for its function in the mitochondria as a key participant in the life-supporting function of ATP synthesis. However, when a cell receives an apoptotic stimulus, cytochrome c is released into the cytosol and triggers programmed cell death through apoptosis.
What is the role of ATP and Nadph in photosynthesis?
So in summary, there are two main roles of NADPH and ATP: (1) they tie the light dependent reactions and the light independent reactions together and (2) they act as sources of energy to take the energy from the sun to the light independent reactions to make the plants food.
What is CAM pathway?
Crassulacean acid metabolism, also known as CAM photosynthesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions that allows a plant to photosynthesize during the day, but only exchange gases at night.
How do cytochromes move electrons?
Electron transfer from cytochrome c occurs by electrostatic binding to subunit II, which should be followed by electron transfer through the CuA center to heme a or heme a3, see Figure 1. Heme a is coordinated by two axial histidine ligands (His102 and His421) provided from different helices.
How do cytochromes differ from hemoglobin?
The tertiary structure of cytochrome c consists of a single polypeptide chain with a covalently bonded heme ring (Salemme, 1977). Unlike myoglobin and hemoglobin proteins, cytochrome c does not have the 6th position of the heme ring available to bind with ligands (Faustman et al., 1996).