What is the difference between Cymru and Gymru? croeso i gymru.
Contents
| Cyclic Photophosphorylation | Noncyclic Photophosphorylation |
|---|---|
| Does not occurs | Occurs |
| Product | |
| ATP | Reduced coenzymes and ATP |
| Electron acceptor | |
In Cyclic PhotophosphorylationP700 is the active reaction center. In non-Cyclic PhotophosphorylationP680 is the active reaction center. Electrons passes in a cyclic manner. Electrons passes in a non – cyclic manner. Electrons return back to Photosystem I.
Cyclic photophosphorylation This transport chain produces a proton-motive force, pumping H+ ions across the membrane and producing a concentration gradient that can be used to power ATP synthase during chemiosmosis.
The photophosphorylation process which results in the movement of the electrons in a cyclic manner for synthesizing ATP molecules is called cyclic photophosphorylation. In this process, plant cells just accomplish the ADP to ATP for immediate energy for the cells.
The ATP and NADPH from the light-dependent reactions are used to make sugars in the next stage of photosynthesis, the Calvin cycle. In another form of the light reactions, called cyclic photophosphorylation, electrons follow a different, circular path and only ATP (no NADPH) is produced.
In this way, electron completes a whole cycle starting from electron activation by energy, leaving chlorophyll, enters into electron transport chain and again back to original position i.e. chlorophyll (a reaction centers). Hence, this type of photophosphorylation is called cyclic photophosphorylation.
In linear electron flow (unbroken arrows) energy from absorbed photons is used to oxidise water on the luminal face of photosystem II (PS II). … In cyclic electron flow, energy from absorbed photons causes the oxidation of the reaction centre (P700) in PS I.
With the cyclic pathway, plants can save some time and energy. Since photosystem I is accepting electrons that are returned to it, it is not accepting electrons from the previous electron transport chain. Therefore, the first electron transport chain will be backed up, which means that photolysis will not occur.
What is the role of water in cyclic photophosphorylation? It provides electrons and protons. Where do the electrons from photosystem I ultimately go after they are passed through the electron transport proteins? They return to photosystem I.
Noncyclic electron transport produces ATP AND NADPH. Cyclic electron transport only produced ATP. A plant needs both processes to make enough ATP necessary for the Calvin Cycle.
Cyclic photophosphorylation can be defined as the synthesis of ATP coupled to electron transport activated by Photosystem I solely, and can therefore proceed in long-wave-length light (03BB 2265 700 nm). This proces is unaffected by the specific inhibitors of Photosystem II, such as CMU, DCMU and orthophenanthroline.
Cyclic Photophosphorylation is the process in which organisms (like prokaryotes), just accomplish the conversion of ADP to ATP for immediate energy for the cells. This type of photophosphorylation usually occurs in the thylakoid membrane.
What is the role of water in noncyclic photophosphorylation? It directly generates ATP. It harvests light energy. It collects the electrons for the Calvin-Benson cycle.
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, b6f, to another transport protein, plastocyanin (Pc), and back to photosystem I.
Electrons cycle back to reduce P870, so this is a cyclic electron transport chain leading to generation of ATP through cyclic photophosphorylation. Unlike in oxygenic photosynthesis, where NADPH is the terminal electron acceptor, no NADPH is made because electrons are cycling back into the system.