pictures and notes are based and from YouTube Redox Reactions: transfer of electrons between substances (LeO GeR) Reduction Reaction: a substance gains electrons Oxidation Reaction: a substance loses electrons Light Dependent Reaction: 1st stage of Photosynthesis Where: Thylakoid membrane in the Chloroplast Thylakoid (highlighted) in the Chloroplast. Structures: Photosystems (1&2): have pigments (chlorophyll) which capture light > excite/energize electrons Oxygen Evolving Com