C HAPTER . What do we Know? . Early Experiments .
Where does Photosynthesis take place? . How many Pigments are involved in Photosynthesis? .
What is Light Reaction? . The Electron Transport . Where are the ATP and NADPH Used?
. The C Pathway . hotorespiration . Factors affecting Photosynthesis Another experiment you may have carried out where a part of a leaf is enclosed in a test tube containing some KOH soaked cotton (which absorbs CO ), while the other half is exposed to air.
The setup is then placed in light for some time. On testing for the presence of starch later in the two parts of the leaf, you must have found that the exposed part of the leaf tested positive for starch while the portion that was in the tube, tested negative. This showed that CO was required for photosynthesis. Can you explain how this conclusion could be drawn?