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They pass through a series of compounds to photosystem I, losing energy along the way.
Photosystem I, like photosystem II, emits high-energy electrons in the light, and the electrons from photosystem II replace these.
Photosystem II contains chlorophyll molecules. When a photon (quantum of light) reaches one of these chlorophyll molecules, the light energy activates an electron.
This is then passed to the reaction center of the photosystem, where there are two molecules of chlorophyll P680. These pass the electrons to plastoquinone, which, like the chlorophylls, is embedded in the thylakoid membrane. The plastoquinone changes its position within the membrane, and passes the electrons to cytochromes b6 and f.
At this stage the electrons part with a significant proportion of their energy, which is used to pump protons (H+) into the thylakoid lumen. These protons will later be used to generate ATP by chemiosmosis. The electrons now pass to plastocyanin, which is outside the membrane on the lumen side.
Photosystem I is affected by light in much the same way as photosystem II. Chlorophyll P700 passes an activated electron to ferredoxin, which is in the stroma (the liquid outside the thylakoid). Ferredoxin in turn passes the electrons on, reducing NADP+ to NADPH + H+.
Photosystem I accepts electrons from plastocyanin. So, effectively, photosystem II donates electrons to photosystem I, to replace those lost from photosystem I in sunlight.
How does photosystem II recover electrons? When it loses an electron, photosystem II becomes an oxidizing agent, and splits water: 2H2O forms 4H+ + 4e- + O2. The electrons return photosystem II to its original state, and the protons add to the H+ concentration in the thylakoid lumen, for later use in chemiosmosis. The oxygen diffuses away.
Wiki User
∙ 15y ago
Wiki User
∙ 13y agoThe electrons of photosystem 1 go down an electron transport chain (protein ferredoxin) were the reach the enzyme NADP+ reductase. Here the electrons (one at a time) will reduce (give electrons to) NADP+. Two electrons turns NADP+ and H+ into NADPH. NADPH will be used later during the Calvin cycle.
From Photons
Wiki User
∙ 11y ago1. Photolysis of water and formation of energy rich compounds; O2 comes out
2. CO2 assimilation by utilizing the energy from energy rich compounds
Wiki User
∙ 11y agoNADPH ....yeah i think...cats
Anonymous
Wiki User
∙ 12y agoIt becomes part of the NADPH
Wiki User
∙ 13y agoFrom energy in Photons
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What is the explanation for the pathway of electron transport chain?
It's a pathway where electrons are transported from photosystem 2 to photosystem 1.
True or false an electron transport chain connects photosystem 1 and photosystem2?
true
Where do electrons get their energy in photosystem I?
From energy in photons
Is the energy from sunlight trapped by chlorophyll located in the electron transport chain?
No, the energy trapped by chlorophyll is located in photosystem I and II. Light energy is first captured by PS II and an electron is then transferred to a primary electron acceptor known as plastoquinone. Pq then transfers it's electron to the cytochrome complex that transfers its energy to the electron transport system which passes it on to plastocyanin which in turn gives its electron to PS I where it is re-excited by photons. This process is known as the electron transport but the energy captured by chlorophyll is located in the photosystems.
What are the products of a non-cyclic electron flow?
In photosynthesis, the noncyclic electron flow produces enzymes called cytochrome b6f complex. Its function is to catalyze the electron transfer of plastoquinol to plastocyanin.
What happens when an excited electron is passed to an electron acceptor in a photosystem?
When an excited electron is passed to an electron acceptor in a photosystem, energy in sunlight is transformed to chemical energy.
What happen to the light energy that is trapped by the chloroplast during the first stage of photosynthesis?
Light energy is not exactly trapped. The light energy excites the electron in the reaction centres of photosystem I and photosystem II. The electron excites and transfers to the electron transport chain ( chain of electron carriers), this produces ATP. Then the electron of photosystem II is transferred by photosystem I and the electron of the photosystem I is used with H+ and NADP to form NADPH. Photosystem II gets back an electron from photolysis of water.
What fills the electron hole in photsystem 1 and 2?
In photosystem 2- water(photolysis) In photosystem 1 - electron from photosystem 2
What happens to electrons when pigments in photosystem absorb lights?
Photosystem's electron travel through the electron transport chain(etc) where ATP is produced and then back to the photosystem. In non-cyclic photophosphorylation, Photosystem II electron then is absorbed by photosystem I, photosystem I electron used to form NADPH and photosystem II gets its electron from photolysis of water. For you unfortunate children using Novanet: They move through an electron transport chain to photosystem 1.
What happens to electrons when pigments in photosystem II absorbs light?
they move through an electron transport chain to photosystem 1
What protein complex absorbs in energy that used to produce NADPH?
Photosystem 1
What is the role of photosystem 1 in the light reactions?
is a cluster of pigments, with a perticular chlorophyl in the center. The energy is absorbed and is then passed to the Hugh energy electrons, NADP will then pick up the electrons and make NADPH
Where does photosystem 2 and photosystem 1 occur?
1. Photosystem I is found in the membrane facing the inside of the grana and Photosystem II is found in membrane facing the stromaTHYLAKOID MEMBRANE
The production of ATP in photosynthesis is called?
it requires energy to be lost from the downhill movement of the excited electron from photosystem 2 to photosystem 1. the energy lost is coupled to ATP formation
What is the explanation for the pathway of electron transport chain?
It's a pathway where electrons are transported from photosystem 2 to photosystem 1.
An electron transport chain connects photosystem1 and photosystem2?
They return to Photosystem I
What happens to the light energy that is trapped by the chloroplast during the first stage of photoynthesis?
It is used to convert 6H2O+6CO2 into C6H12O6+O2, which is glucose and oxygen. The light energy is also converted to energy which the plant uses. The plant also uses the glucose it makes and releases the O2as a byproduct.
