Photosynthesis (SPM level)

Photosynthesis – takes place in the chloroplast.

Light reaction (occurs in grana; splitting up water molecules – photolysis of water)

Dark reaction (occurs in stroma; fixation of carbon dioxide)

Light reaction - occurs in the grana (contained chlorophyll) - takes place in the presence of sunlight and chlorophyll - chlorophyll absorbs light; then it becomes activated and this energy is used to :

i) produce energy in the form of – ATP (used for dark reaction)

ii) split up water molecules (photolysis) into hydroxyl ions(OH-) and hydrogen ions (H+) - oxygen is released; but hydrogen enters dark reaction.

Dark reaction (Light independent reaction) - takes place in the stroma -ATP combined with hydrogen atoms (from the light reaction) are used to reduce carbon dioxide to form glucose.

Glucose produced –

i) converted to starch (stored),

ii) transformed - sucrose ; transported to other parts

iii) synthesis of cellulose

iv) converted to a. acids and fatty acids.