Definition of light reaction in English:

light reaction


  • 1mass noun The reaction of something, especially the iris of the eye, to different intensities of light.

    ‘The investigator simply has to set the parameter representing the light reaction activity to zero, and recalculate the steady-state.’
  • 2the light reactionBiochemistry
    The reaction which occurs as the first phase of photosynthesis, in which energy in the form of light is absorbed and converted to chemical energy in the form of ATP.

    • ‘Two proteins may participate in the light reaction.’
    • ‘The light reaction relies upon two clusters of pigments, known as photosystems I and II, which each possess a different type of chlorophyll and several accessory pigments.’
    • ‘Chlorophyll and several other pigments such as beta-carotene are organized in clusters in the thylakoid membrane and are involved in the light reaction.’
    • ‘This allows oxygen to diffuse past the ‘gatekeeping’ mitochondria and into the peroxisomes, initiating the light reaction.’
    • ‘During this second stage of photosynthesis, NADPH 2 and ATP produced in the light reaction are used to reduce CO 2 to organic carbon.’