photosynthesis

• The light-dependent reactions occur in the thylakoid membranes, while the Calvin cycle occurs in the stroma.
• In pathway 1, the electrons flow along a sequence of electron acceptors(2 electrons at a time). The electrons return back to the chlorophyll molecule. The electrons lose energy as they move through pathway one. The energy is used to convert ADP to ATP
• In pathway 2, two high energy electrons move from the electron acceptor to other electron acceptors. As they move they lose energy and this energy forms ATP. Eventually the 2 electrons join to NADP+ to make NADP
• The Dark stage/light independent stage does not need light to occur but needs the products from the light stage (NADPH and ADP)
• NADPH will supply electrons and protons for the dark stage
• ATP will supply energy for the dark stage to occur
• the dark stage takes place in the chloroplast
• a pair of electrons leaves the chlorophyll molecule and pass along a sequence of electron acceptors/carriers(ADP-ATP).
• the pair of electrons join with NADP+ to form NADP-
• Water is split using light energy (photolysis). the formulas for this 2H2O->4H+ +4e+O2/ H20->2H+ +2e+ 1/2 O2
• Protons are stored in the proton pool
• electrons released return to the chlorophyll molecule to replae the pair that left
• Oxygen will be released into the atmosphere or used by the plant for respiration
• A proton from the proton pool will combine with NADP- to form NADPH
• The Calvin cycle uses ATP, CO2 and NADPH to make glucose
• In the calvin cycle, carbon dioxide enters the stroma through openings called stomata