Where do the electrons in photosystem II come from?
Photosystem II obtains replacement electrons from water molecules, resulting in their split into hydrogen ions (H+) and oxygen atoms. The oxygen atoms combine to form molecular oxygen (O2), which is released into the atmosphere.
Where does photosystem II obtain its electrons quizlet?
The photosystem pulls replacement electrons from water molecules, which break apart into oxygen and hydrogen ions. The oxygen leaves the cell as O2. The electrons enter an electron transfer chain in the thylakoid membrane.
How does an electron get from photosystem 2 to photosystem 1?
After the photon hits, photosystem II transfers the free electron to the first in a series of proteins inside the thylakoid membrane called the electron transport chain.
Does photosystem II come first or second in the electron transport chain?
photosystem II. There are two types of photosystems in the light-dependent reactions, photosystem II (PSII) and photosystem I (PSI). PSII comes first in the path of electron flow, but it is named as second because it was discovered after PSI.
What is the source of replacement electrons for those released from photosystem II?
The source of replacement electrons for those released from photosystem 2 are electrons from the split of water.
How many electron transport chains are in photosystem II?
Answer and Explanation: In photosynthesis, there are two electron transport chains.
What occurs in photosystem II?
Photosystem II is the first link in the chain of photosynthesis. It captures photons and uses the energy to extract electrons from water molecules.
What excites the electrons out of photosystem II?
First, a photon excites an electron in the pigment molecules of photosystem II's antenna complex, and resonance occurs until the energy reaches the reaction center. The electrons of photosystem II will be replaced by electrons stripped from water, producing oxygen gas as a by-product.
How do electrons enter the electron transport chain?
It occurs in mitochondria in both cellular respiration and photosynthesis. In the former, the electrons come from breaking down organic molecules, and energy is released. In the latter, the electrons enter the chain after being excited by light, and the energy released is used to build carbohydrates.
What is the source of replacement electrons?
Photosystem I obtains replacement electrons from the electron transport chain. ATP provides the energy and NADPH provides the hydrogen atoms needed to drive the subsequent photosynthetic dark reaction, or Calvin cycle.
Where does photosystem 1 get its electrons?
Photosystem I receives electrons from plastocyanin or cytochrome c6 on the lumenal side of the thylakoid membrane and uses light energy to transfer them across the membrane to ferredoxin on the stromal side. It can also function in a cyclic electron transport pathway.
Which of the following is a source of replacement electrons for photosystem II during photosynthesis?
In (a) photosystem II, the electron comes from the splitting of water, which releases oxygen as a waste product.
Where do electrons that are excited by the energy in sunlight come from?
The light excites an electron from the chlorophyll a pair, which passes to the primary electron acceptor. The excited electron must then be replaced. In (a) photosystem II, the electron comes from the splitting of water, which releases oxygen as a waste product.
What is the source of replacement electrons for those released from photosystem I?
Photosystem I obtains replacement electrons from the electron transport chain. ATP provides the energy and NADPH provides the hydrogen atoms needed to drive the subsequent photosynthetic dark reaction, or Calvin cycle.
How are electrons transported to the membrane at the beginning of the electron transport chain?
The electron transport chain is a series of electron transporters embedded in the inner mitochondrial membrane that shuttles electrons from NADH and FADH2 to molecular oxygen. In the process, protons are pumped from the mitochondrial matrix to the intermembrane space, and oxygen is reduced to form water.
Where does the electron transport chain take place in photosynthesis?
the thylakoid membrane In photosynthetic eukaryotes, the electron transport chain is found on the thylakoid membrane.
How are electrons generated in photosynthesis?
This is accomplished by the use of two different photosystems in the light reactions of photosynthesis, one to generate ATP and the other to generate NADPH. Electrons are transferred sequentially between the two photosystems, with photosystem I acting to generate NADPH and photosystem II acting to generate ATP.
Does photosystem 2 use an electron transport chain?
In the photosynthetic photosystem II, electrons are transferred from the manganese-containing oxygen evolving complex (OEC) to the oxidized primary electron-donor chlorophyll P680•+ by a proton-coupled electron transfer process involving a tyrosine-histidine pair.
Where does the supply of electrons come from?
Where does the supply of electrons come from and where do they end up at the end of L-D set of reactions? It comes from splitting water molecules and the electrons end up reducing NADP+ into NADPH. What are the products results specifically from photosystem 1 and photosystem 2? The products are O2, ATP, and NADPH.
Where do photosystem 1 electrons come from?
Photosystem I receives electrons from plastocyanin or cytochrome c6 on the lumenal side of the thylakoid membrane and uses light energy to transfer them across the membrane to ferredoxin on the stromal side.
How do electrons gain energy in photosystem?
Answer and Explanation: Electrons in Photosystem I gain their energy when chlorophyll or carotenoid molecules absorb light and get into a photoexcited state.
What is a product of the electron transport chain started by photosystem II?
High-energy electrons form when pigments in photosystem II absorb light. The electrons pass through electron transport chains, a series of electron carrier proteins. The movement of electrons through an electron transport chain causes a thylakoid to fill up with hydrogen ions and generates ATP and NADPH.
Where does the electron transport chain take place in the mitochondria?
inner mitochondrial membrane Electron transport chain (ETC) occurs in the inner mitochondrial membrane, where the OXPHOS takes place through the action of ATP synthase, (37).
Where are electrons generated in photosynthesis?
From photosystem II, electrons are carried by plastocyanin (a peripheral membrane protein) to photosystem I, where the absorption of additional photons again generates high-energy electrons.
Where do electrons come from in light reactions?
Light reactions occur when plants synthesize food from carbon dioxide and water, referring specifically to the part of energy production that requires light and water to generate electrons needed for further synthesis. Water provides the electrons by splitting into hydrogen and oxygen atoms.
Where does the supply of electrons come from and where do they end up at the end of light dependent set of reactions?
Where does the supply of electrons come from and where do they end up at the end of LD set of reactions? comes from the splitting of water and ends up in NADPH+.
What does photosystem 2 do in photosynthesis?
Photosystem II is the first link in the chain of photosynthesis. It captures photons and uses the energy to extract electrons from water molecules.
Where does electron transport take place?
The electron transport chain activity takes place in the inner membrane and the space between the inner and outer membrane, called the intermembrane space.
Where does the first electron come from in photosynthesis?
What is the source of electrons in photosynthesis? In photosynthesis water is the source of electrons and their final destination is NADP+ to make NADPH.
How are electrons transferred in photosynthesis?
Electrons are transferred sequentially between the two photosystems, with photosystem I acting to generate NADPH and photosystem II acting to generate ATP. The pathway of electron flow starts at photosystem II, which is homologous to the photosynthetic reaction center of R. viridis already described.