075 MONITORING RESPIRATION BY PHENOLPHTHALEIN

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075 MONITORING RESPIRATION BY PHENOLPHTHALEIN
Though several methods are mentioned to observe
respiration in germinating seeds, this
experiment uses Phenolphthalein indicator with a
water flush.
MATERIALS REQUIRED
A bottle with a two-holed cork or a rubber cork
through which you can drill Germinating
seeds Phenolphthalein indicator A Syringe A
plastic tube
Syringe
Phenolphthalein
Tube
Germinating seeds
Bottle with rubber cap
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Set the unit as shown in the picture and leave
undisturbed for about an hour or more. After that
inject water from the syringe into the bottle.
This bottle flushes the carbon dioxide as
carbonic acid into the phenolphthalein which
changes colour from pink to colourless (achromic
point) confirming respiration.