A photosystem consists of 1) a light-harvesting complex and 2) a reaction center.   Privacy There are other forms of plastoquinone, such as ones with shorter side chains like PQ-3 (which has 3 isoprenyl side units instead of 9) as well as analogs such as PQ-B, PQ-C, and PQ-D, which differ in their side chains. Do not make any stray marks on the, Answer Sheet. But, plastocyanin is a small water-soluble blue-copper protein that accepts a pair of electrons from the cytochrome b 6 f complex and passes it to photosystem I in the thylakoid space. It is composed of many molecules of chlorophyll a, chlorophyll b and carotenoids. Both cytochrome b ƒ –ƒ and plastoquinone (PQ) are oxidized by far red light and reduced by light of shorter wavelength. Photosystem II (PSII) functions to capture light energy and transfer it to plastoquinone, the first molecule in an electron transport chain that leads to the production of ATP. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students. In light reaction, plastoquinone facilitates the transfer of electrons from (1) PS-I to NADP + (2) PS-I to ATP synthase (3) PS-II to Cytb 6 f complex (4) Cytb 6 f complex to PS-I Answer (3) Sol. Answer_and_Solution_NEET-2020_Code-G5(1).pdf, Delhi Technological University • POLS MISC, Ans_Solutions_NEET2020_(Code-H1)_qUFwey3.pdf, Delhi Technological University • FINANCE 101, Delhi Public School, R.K. Puram • BIOLOGY 123, Copyright © 2021. The cytochrome complex, an enzyme composed of two protein complexes, transfers the electrons from the carrier molecule plastoquinone (Pq) to the protein plastocyanin (Pc), thus enabling both the transfer of protons across the thylakoid membrane and the transfer of electrons from PSII to PSI. In gel electrophoresis, separated DNA fragments can be visualized with the help of . Plastoquinone (PQ) is an isoprenoid quinone molecule involved in the electron transport chain in the light-dependent reactions of photosynthesis. for writing particulars on this page/marking responses. After excitement, e – is passed from PS-II (P 680) to primary electron acceptor (Pheophytin). Fourier transform infrared spectroscopy can be used to obtain information about the structural changes that accompany electron transfer in photosystem II. 16. The overall function of light-dependent reactions, the first stage of photosynthesis, is to convert solar energy into chemical energy in the form of NADPH and ATP, which are used in light-independent reactions and fuel the assembly of sugar molecules. copy number of the linked DNA in the vector. It uses the energy of sunlight to transfer electrons from water to a mobile electron carrier in the membrane called plastoquinone: H 2 O → P680 → P680 * → plastoquinone. - [Voiceover] In a previous video, we gave an overview of the light dependent reactions which are essentially occurring across the thyla or within or across the thylakoid membranes, right that we zoomed in on one and we saw okay we have some energy from light exciting the electrons within that chlorophyll pair, that P680 chlorophylled A pair. Can you explain this answer? On completion of the test, the candidate must handover the Answer Sheet to the Invigilator before leaving, The candidates should ensure that the Answer Sheet is not folded. Course Hero, Inc. C water C plastoquinone (Pq) C plastocyanin (PC) C ATP C ferredoxin (Fd) light | EduRev NEET Question is disucussed on EduRev Study Group by 128 NEET Students. It not only transfers the electrons for PS I but also is responsible for ATP production. Explain how during light reaction of photosynthesis, ATP synthesis is a chemiosmotic phenomenon. These photosystems absorb and utilize the solar energy efficiently in the thylakoid membranes. Each candidate must show on demand his/her Admission Card to the Invigilator. light-reactions - 4 stages primary photoevent - light photon captured by pigment, exciting the electrons in the pigment; charge separation - energy transferred to reaction center (special chlorophyll pigment) transfers energetic electron to acceptor molecule, starts electron transport Course Hero is not sponsored or endorsed by any college or university. The electrons are transferred (by way of plastoquinone — PQ in the figure) to the cytochrome b 6 /f complex where they provide the energy for chemiosmosis. The reaction center chlorophyll contains electrons that can be transferred when excited. Name the enzyme that facilitates opening of DNA helix during transcription. No part of the Test Booklet and Answer Sheet shall be detached under any circumstances. : 011-47623456, In light reaction, plastoquinone facilitates the, plastoquinone. The process of photosynthesis: the light reactions Light absorption and energy transfer. Due to the higher midpoint potential of plastoquinone in the Q A site than Pheo − the charge-separated state is stabilized, reducing the probability of a back reaction between Q A − and P680 +. Cytochrome b6f engages in two different processes with the electrons it receives from plastoquinone: non-cyclic transport and cyclic electron transport. In light reaction, plastoquinone facilitates the transfer of electrons from (1) Cytb 6f complex to PS-I (2) PS-I to NADP+ (3) PS-I to ATP synthase (4) PS-II to Cytb 6f complex Answer (4) Sol. Use of Electronic/Manual Calculator is prohibited. In addition to the two electrons, Qb also picks up two protons from the stroma. The most common form of plastoquinone, known as PQ-A or PQ-9, is a 2,3-dimethyl-1,4-benzoquinone molecule with a side chain of nine isoprenylunits. Plastoquinone (PQ) in turn, plastoquinone facilitates the transfer of, The sequence that controls the copy number, of the linked DNA in the vector, is termed, sequence is responsible for controlling the. B) The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. After excitement, e – is passed from PS-II (P 680 ) to primary electron acceptor (Pheophytin). The reaction center of PSII (called P680) delivers its high-energy electrons, one at the time, to the primary electron …   Terms. 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