The light and dark reactions of Photosynthesis.

Including Photosystems, I and II.

Photosynthesis is a two-stage process, the light reactions using photons of light energy to drive molecules to a higher energy state and dark reactions which use the energy molecules to fix carbon dioxide into 6 carbon sugars.

The dark reaction doesn’t have to be in the dark and is also called the light independent reaction.

These reactions are sometimes referred to as photosynthesis 1 (light) and photosynthesis 2 (dark), not to be confused with photosystems I and…



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store
Peter Miles

45 years in Environmental Science, B.Env.Sc. in Wildlife & Conservation Biology. Writes on Animals, Plants, Soil & Climate Change.