What are the 3 Parts in Light Reaction
- Photoexcitation and Photolysis
- Electron Transport
- Photophosphorylation( chemiosmosis)
What is the process of Photoexcitation and Photolysis
- Excites electrons of the electron carriers from using the photon that was ammited by the Light Energy
- The energy from light photon are use to split water to oxygen which releases more energy
Process of Electron Transport in Light Reaction
- To do electrochemical Gradients (pumping hydrogen ions against its concentration gradients)
- Helps for the final step for Light Reaction
Process of Photophosphorylation (chemiosmosis) in Light Reaction
-ATP synthesis due to electrochemical gradient and the proton motive force
What happens if the excited electro does not get accepted by electron carriers
- They are gonna go back to ground state
- Heat and light are realized
Where Chlorophyll found?
- Is found in the thylakoid membrane
- Is a cluster of PIGMENT
How many pigments in Photosystem Structure? Where is the primary electron acceptor located in the Photosystem Structure?
- There are a few hundred pigments
- The Primary electron acceptor (PEA) is located beside reaction center chlorophyll
What are the 2 types of Photosystems
- Photosystem 1 P700
- Photosystem 2 P680
- The number shot optimal wavelength for absorption
Where does the Electro Transport Chain occurs?
-In the thylakoid membrane
What are the three proton in Thylakoid membrane that help with moving Primary Electron Acceptors between complexex?
- Plastquinone (Pq)
- Plastocyanin(Pc)
- Ferredoxin(Fd)
What are the four complex in the Electron Transport chain of Thylakoid membrane?
ETC -Photosystem 2 (PS2)(P680) -Cytochrome Complex -Photosystem 1 (PS1)(P700) -NADP+ reductase (an enzyme) ATP Synthesis -ATP Synthase
Thylakoid Proteins: Photosystem 2
P680
- Occurs first
- PS@ absorb Light
- Excited electron go in the reaction centre chlorophyll and is captured by the Primary Electron Accepter (PEA)
- P680 loses an electron and now it will be oxidized (P680+)
Thylakoid Proteins: Plastquinone (Pq)
- Helps the Primary Electron Accepter (PEA) to travel through ETC
- Electron -> plastiquions
- Since it is mobile, helps transfer that electron to the next complex
Thylakoid Proteins: Cytochrome Complex
- The Pq helps transfer the electron from PS2 to Cytochrome Complex
- While that is happening, the proton from the stroma are pumped agains its concentration gradient and into Lumen
- Those Proton will later be used to synthesis ATP in ATP synthesis step
Thylakoid Proteine: Plastocyanin (Pc)
- Electron form Cytochrome Complex is transferred through the use of Plastocyanin
- This Pc is located on the lumen side of the Thylakoid membrane
Thylakoid Proteine: Photosystem 2 (PS1)(P700)
- Another ETC occurs where this system takes the light photon form surrounding and uses it to excite electrons
- This excited electron is captured by PEA and is send to the next stage leaving the system (PS1) oxidized
- But the Pc that carried the electron will donate its electron to PS1 so it could go back to being neutral
Thylakoid Proteine: Ferradoxin (Fd)
- The PEA is now transferred to a mobile proton called Ferradoxin (Fd)
- Ferradoxin is on the Stroma side
- Carries the PEA to the next complex
Thylakoid Proteine: NADP+ Reductase
- NADP+ Reductase is an enzyme
- The ferrodoxin helps transfer its electron to NADP+ reductase which helps put electron to the final electron accepter NADP+
- NADP+ —> Reduced to NADPH
What is the Purpose of NADPH
-NADPH will provide reducing power for the making of sugar in Calvin Cycle
How does PH2 replace its lost electron?
- we know that PS2 is a strong oxidizer
- Electron from water (located in Lumen)is excited and they break
- Those electron are used to help PH2 to become neutral form PH2+
Thylakoid Proteins: ATP Synthase
- Protons that were pumped through the stroma to the lumen in cytochrome complex and the protons that were created when replacing the lost electron in PS2 are used
- ATP synthase uses those proton to pump them into it self like the Cellular Respiration
- ATP is produced in the stroma
