Search results
Jan 18, 2022 · Light-dependent reaction is the series of biochemical reactions in photosynthesis requiring light energy that is captured by light-absorbing pigments (such as chlorophyll) to be converted into chemical energy (ATP and NADPH).
- Visible Light
Visible light is the electromagnetic radiation at...
- Pigments
pigment 1. Any material from which a dye, a paint, or the...
- Visible Light
- 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.
The light-dependent reactions convert light energy into chemical energy. The goal of the light-dependent reactions of photosynthesis is to collect energy from the sun and break down water molecules to produce ATP and NADPH.
The overall function of light-dependent reactions, the first stage of photosynthesis, is to convert solar energy into chemical energy in the form of NADPH and ATP, which are used in light-independent reactions and fuel the assembly of sugar molecules.
In light reactions, energy from the sunlight is absorbed by the pigment chlorophyll and is converted into chemical energy in the form of electron charge carrier molecules such as NADPH and ATP. Light energy is utilized in both the Photosystems I and II, present inside thylakoid membranes of the chloroplasts.
- 13 min
Light-dependent reactions are certain photochemical reactions involved in photosynthesis, the main process by which plants acquire energy. There are two light dependent reactions: the first occurs at photosystem II (PSII) and the second occurs at photosystem I (PSI).
Sep 21, 2021 · The light-dependent reactions begin in a grouping of pigment molecules and proteins called a photosystem. Photosystems exist in the membranes of thylakoids. A pigment molecule in the photosystem absorbs one photon, a quantity or “packet” of light energy, at a time.