light reaction
Noun: - The initial phase of photosynthesis in which light energy is absorbed and converted into chemical energy in the form of ATP and NADPH. This process occurs in the thylakoid membranes of chloroplasts and does not directly produce sugars or require carbon dioxide.
The term "light reaction" is used specifically in the context of plant biology and biochemistry to describe the light-dependent steps of photosynthesis. - The efficiency of the light reaction determines how much energy is available for the Calvin cycle. - Researchers are studying how to enhance the light reaction in crops to improve yield.
- "to drive the light reactions": Refers to the provision of light energy that powers the photochemical processes.
- Sunlight drives the light reactions in the plant's chloroplasts.
- "light reaction center": A specific complex of proteins and pigments within a photosystem where the initial electron transfer occurs.
- The photon's energy is funneled to the light reaction center.
- Light-dependent reactions: A synonymous phrase often used interchangeably with "light reaction."
- Photophosphorylation: The process of generating ATP during the light reactions.
- Photosystem I and II: The two protein complexes that facilitate the light reactions.
- Light-dependent phase
- Photochemical phase
- "Z-scheme of electron flow": A model describing the path of electrons through the photosystems during the light reactions.
The "light reaction" is distinct from the subsequent "dark reaction" (or Calvin cycle), which uses the ATP and NADPH produced to fix carbon dioxide into sugars.
- the first stage of photosynthesis during which energy from light is used for the production of ATP