SEVERAL MEMBRANE BOUND PROTEIN COMPLEXES ARE INVOLVED IN THE ENERGY CONVERSION PROCESSES. COMPARE THE PHOTOSYSTEM II AND PHOTOSYSTEM I PROTEIN COMPLEXES COMPONENTS BY TABULATING THE DIFFERENCES AND SIMILARITIES?
Differences:
Photosystem II (PSII) Protein Complex Components:
1. Reaction center proteins: PSII contains a reaction center protein called P680, which has an absorption peak at around 680 nm.
2. Antenna pigments: PSII has various antenna pigments like chlorophyll a, chlorophyll b, and carotenoids that capture light and transfer the energy to the reaction center.
3. Oxygen evolving complex (OEC): PSII has an OEC that is responsible for the oxidation of water, releasing oxygen as a byproduct.
4. Cytochrome b6f complex: This protein complex is involved in electron transfer between PSII and PSI.
Photosystem I (PSI) Protein Complex Components:
1. Reaction center proteins: PSI contains a reaction center protein called P700, which has an absorption peak at around 700 nm.
2. Antenna pigments: PSI also has antenna pigments like chlorophyll a, chlorophyll b, and carotenoids that capture light and transfer the energy to the reaction center.
3. Ferredoxin: PSI transfers electrons to ferredoxin, which acts as an electron carrier in various metabolic reactions.
4. NADP+ reductase: This enzyme is involved in the reduction of NADP+ to NADPH, which serves as a carrier of high-energy electrons for subsequent metabolic processes.
Similarities:
1. Both PSII and PSI are protein complexes found in the thylakoid membrane of chloroplasts.
2. Both complexes contain reaction center proteins that absorb light energy and transfer it to the electron transport chain.
3. Both complexes have antenna pigments that capture light energy and transfer it to the reaction center.
4. Both complexes are involved in the process of photosynthesis and play a crucial role in energy conversion.
To compare the components of the Photosystem II (PSII) and Photosystem I (PSI) protein complexes, we can create a table to highlight their differences and similarities:
Differences:
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| PSII | PSI |
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| Absorbs light at shorter | Absorbs light at longer |
| wavelengths (around 680nm) | wavelengths (around 700nm) |
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| Contains a manganese cluster | Contains a lesser |
| involved in the electron | known electron acceptor |
| transport chain | and multiple iron-sulfur |
| | clusters |
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| Generates oxygen as a | Does not generate oxygen |
| byproduct | as a byproduct |
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| Transfers electrons from | Transfers electrons to |
| water to plastoquinone | ferredoxin |
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| Located in the | Located on the outer |
| membrane stacks called | surface of the thylakoid |
| grana | membrane |
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Similarities:
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| PSII | PSI |
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| Both are photosynthetic | Both absorb light energy |
| protein complexes involved | and convert it into |
| in the conversion of light | chemical energy |
| energy into chemical energy | |
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| Both contain chlorophyll | Both contain pigments such |
| and accessory pigments | as chlorophylls and |
| | carotenoids |
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| Both participate in the | Both transfer electrons |
| electron transport chain | during the light-dependent |
| during the light-dependent | reactions of photosynthesis |
| reactions of photosynthesis | |
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| Both contribute to the | Both help in the generation |
| proton gradient used to | of ATP and NADPH for the |
| generate ATP and NADPH | Calvin cycle |
| during photosynthesis | |
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This table summarizes some of the key differences and similarities between the PSII and PSI protein complexes.