Photosynthesis

In the thylakoid membranes of the chloroplast:

• light energy is absorbed by a chlorophyll molecule
• electrons are excited to a higher energy level
• these electrons are passed along an electron transport chain
• this releases energy which is used to reform ATP from ADP +Pi (oxidative phosphorylation)
• photolysis of water into H+, electrons and oxygen
• H+ goes to NADP converting it to NADP with addition of electrons from the electron transport chain
• electrons replace those lost by chlorophyll and Oxygen is released as gas through stomata

In the STROMA:

• Ribulose Bisphosphate combines with CO2 to from two molecules of Glycerate-3-phosphate
• GP is reduced to TP- addition of hydrogen from reduced NADP and energy released from hydrolysis of ATP to ADP + Pi
• TP gives one carbon to the build up of organic molecules such as glucose for growth
• TP is then phosphorylated back to RuBP, so the cycle continues