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In the light-dependent reactions, which take place at the thylakoid membrane, chlorophyll absorbs energy from sunlight and then converts it into chemical energy with the use of water. The light-dependent reactions release oxygen as a byproduct as water is broken apart.
- Aka The Calvin Cycle
Section Summary. Using the energy carriers formed in the...
- Light and Pigments
The visible light seen by humans as white light actually...
- Aka The Calvin Cycle
- Step 1: Excitation of Photosystems with Light Energy and Photolysis of Water
- Step 2: Generation of ATP by Electron Transport Chain
- Step 3: Formation of NADPH
- Alternative Pathway
- Chemical Equation
- Fate of The Products
The function of the light-dependent reaction is to convert light energy into chemical energy within a multi-protein complex called the photosystem, found in the thylakoid membranes. There are two types of photosystems found in most plants: photosystem I (PSI) and photosystem II (PSII). Each photosystem is made of two components: 1) antenna complex ...
The electrons released from photosystem II enter a chain of proteins known as electron transport chain (ETC). They move from PSII to a small lipid-soluble molecule, plastoquinone (Pq), and then to a protein complex called cytochrome b6f. The electrons are finally transferred to a copper-containing protein called plastocyanin (Pc) before being accep...
This stage is the final step of the light-dependent reaction during which high energy electrons released from PSI travel a short second leg of the electron transport chain. Here, the electrons are first transferred to an iron-containing protein called ferredoxin (Fd) and then to a reducing agent, NADP, to form NADPH. This type of electron transport...
Sometimes plants follow an alternative path of electron transport called cyclic photophosphorylation. This term is named so because electrons released from PSI move along a circular path before returning to the same photosystem. Cyclic photophosphorylation does not involve PSII and produces only the ATP, stopping the production of NADPH.
2H2O + 2NADP+ + 3ADP + 3Pi → O2+ 2NADPH + 3ATP Reactants 1. H2O 2. NADP 3. ADP + Pi End Products 1. O2 2. NADPH 3. ATP
The energy-carrier molecules, ATP, and NADPH produced in the light reaction are used in the second phase of photosynthesis or the Calvin cycle to assemble sugar molecules.
Key Points. Light energy splits water and extracts electrons in photosystem II (PSII); then electrons are moved from PSII to cytochrome b6f to photosystem I (PSI) and reduce in energy. Electrons are re-energized in PSI and those high energy electrons reduce NADP + to NADPH.
Key Points on Light Reaction. The light reaction traps the energy from the sun and converts it into chemical energy that is stored in NADPH and ATP. Oxygen is released as the waste product. Also Read: Electron Transport Chain. To know more about light reaction and the process involved in light reaction, keep visiting BYJU’S website or ...
- 13 min
Light energy enters the process of photosynthesis when pigments absorb the light. In plants, pigment molecules absorb only visible light for photosynthesis. The visible light seen by humans as white light actually exists in a rainbow of colors.
- Charles Molnar, Jane Gair
- 2015
Dec 18, 2021 · The overall function of light-dependent reactions is to convert solar energy into chemical energy in the form of NADPH and ATP. This chemical energy supports the light-independent reactions and fuels the assembly of sugar molecules.
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How do light-dependent reactions convert light energy into chemical energy?
What is the function of light-dependent reactions?
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How do light-dependent reactions begin in photosystem II?
What is the net-reaction of all light-dependent reactions in oxygenic photosynthesis?
Where do the light-dependent reactions of photosynthesis take place?
The reactions that make up the process of photosynthesis can be divided into light-dependent reactions, which take place in the thylakoids, and light-independent reactions (also known as dark reactions or the Calvin cycle), which take place in the stroma.
