084 DIGESTION OF STARCH BY SALIVA

1
084 DIGESTION OF STARCH BY SALIVA
To make students understand the concept of
digestion of starch by the amylase enzyme present
in their own saliva.
MATERIALS REQUIRED
Starch solution (mix atta or rice powder in warm
water) Water Iodine solution (can use tincture
available in pharmacy) Saliva
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Two test-tubes labeled A and B are to be taken, 5
ml of starch solution is taken in each. Then 5
ml of saliva is added to A and an equal amount of
water to B (relevance of controls in
experiments can be discussed here). The mixtures
are to be shaken well and kept aside.
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The presence or absence of starch in both A and B
can be monitored every 5 minutes by taking a
drop of A or B on a white tile or plate and
adding a drop of iodine solution. If the starch
solution is very dilute, it may be better to
check the solutions every two minutes. Presence
of blue colour indicates presence of starch,
while the absence of blue colour confirms that
the starch has been digested by the saliva.