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1. SESSION-2022-23
A
ProjectReport on
“Study of digestionof starch by ptylinand effect of ph and tempreture on it”
Submitted to
Mr. Rajib Lochan Nanda (pgt chemistry)
PRANABALLAV PUBLIC SCHOOL
Gohira, Ghasipura, KEONJHAR
Submitted by
NAME- OMM PURI DAS

2. Roll No. 13
CERTIFICATE
This is certify that Omm Puri Das of class 10+2 of
Pranaballav Public School has performed the project work as
per the syllabus of C.B.S.E. for class 10+2and has tried to give
satisfaction account in this file
Deptt. of Chemistry
Pranaballav Public School
Gohira, Ghasipura

3. ACKNOWLEDGEMENT
I consider it my first duty to express my hearty gratitude to
Chemistry Lecturer Mr. Rajib Lochan Nanda for being always
internally kind and helpful.
Secondly I am thankful to my parents and companion
for sincerely helping me and encouraging me in preparation of
this project.
I am also thankful to my examiners for telling me
my mistakes.
Thanking you.
Name- OMM PURI DAS
XII

4. FORWARD
This project report is submitted in partial fulfillment
of the requirement laid down course prescribed for Chemistry
Project by the Central Board of Secondary Education, New
Delhi for all India Senior Secondary School Certificate
Examination 2020-2021 under the guidance of Mr.
Rajib Lochan Nanda.
Signatures
External Examiner Internal Examiner

5. VERIFICATION
It is verified that Omm Puri Das of class XII of Pranaballav
public School has prepared this project under my guidance.
He/she had done sincere hard work for this project. This
project report may be considered as the requirement laid
down by C.B.S.E. practical pattern.
Deptt. of Chemistry
Pranaballav Public School
Gohira, Ghasipura

6. PREFACE
Name of the Project : Study of digestion of starch by
salivery amylase or ptylin and effect of
pH and temperature on it.
Submitted to : Mr. Rajib Lochan Nanda (PGT Chemistry)
Submitted by : OMM PURI DAS
Roll No. : 13
School : Pranaballav Public School

7. Experiment :1
Objective: -
To study the digestion of starch by salivery amylase.
Apparatus requirement: -
Beaker, conical flask, filter paper, test tube, test tube stand, water bath and
burner.
Chemical required: -
1% of Nacl solution, 1% of Iodine solution, starch and distilled water.
Procedure: -
1. Collection of Saliva:
1. Take about 20-30 ml of warm distilled water at 313 K in your mouth.
Gargle well to mix saliva with distilled water as completely as possible.
2. Transfer the gargled water into a clear beaker and filter it through
fluttedd filter paper into the boiling test tube.
This gives us the required saliva containing the enzyme amylase or ptylin.
2. Preparation of starch solution:
2g of starch + 10 ml of distilled water boil and filter.
3. Study of digestion of starch by salivery amylase:
1. In a test tube take 10 ml of starch and add 2 ml of saliva solution, shake
well to mix. Now place this test tube in a hot water bath at 308-313 K
and note the time.
2. Take several test tube in a test tube stand. Add 5 ml of distilled water

8. and 3-5 drops of 1% Iodine solution to each test tube.
3. After 30 sec. transfer 2 drops of reaction mixture (step 1) into one of the
test tube (step 2) containing iodine solution. Shake the content and note
the colour change, if any repeat the experiment after every 30 sec. till the
iodine solution does not impart any blue colour to the reaction mixture.
Observation: -
Time Colour Imparted with Iodine solution
(Sec.) Iodine solution
30 Deep blue
60 Deep blue
90 Blue
120 Blue
150 Light Blue
180 Light Blue
210 Light Blue
240 Light Blue
270 No Blue Colour
Result: -
The intensity of blue colour goes on decreasing with time and finally no
coloration obtained. These observations suggest that starch is hydrolysed to
glucose and Maltose by the enzyme ptyalin (amylase) present in human saliva.
Precaution: -
Use only a dilute solution of saliva since the rate of the hydrolysis very fast.

9. Experiment :2
Objective: -
To study the effect of pH on the salivary digestion of starch.
Theory: -
All enzyme catalysed reaction are sensitive to pH changes and occur most
efficiently around pH 7 (Neutral Solution). As such, the hydrolysis of starch by salivary
enzymes should not occur under acidic or basic medium.
Apparatus requirement: -
Test tube, conical flask, water bath, glazed tile and burner.
Chemical required: -
Dil. HCl (pH=1), dil. Acetic acid (pH=5), 1% sodium carbonate solution
(pH=9), 2% starch solution, 1% of iodine solution, Fehling solution and distilled water.
Procedure: -
(A) Collection of Saliva: -
1. Take about 20-30 ml of warm distilled water at 313 K in your mouth.
Gargle well to mix saliva with distilled water as completely as possible.
2. Transfer the gargled water into a clear beaker and filter it through a
flutted filter paper into the boiling test tube. This gives us the required
saliva containing the enzyme or ptylin.
(B) Preparation of starch solution: -
2g of starch + 10ml of distilled water boils and filter.
(C) Study of effect of pH on salivaray digestion of starch: -
1. Take 4 clean and dry test tube and lebel them as 1, 2, 3 and 4.

10. 2. Take 5 ml dil. HCl (pH=1) dil. Acetic acid (pH=5), distilled water
(pH=7), 1% of sodium carbonate solution (pH=9) in test tube no.'s 1, 2,
3, 4.
3. Add 5 ml of starch solution and 5 ml of saliva solution to each of the
above test tubes. Shake them well to mix the contents and keep the test
tube in water bath at 308- 313 K.
4. After 30 min., take 1 drop of the reaction mixture from each test tube
and place it on a white glazed tile. Mix it 1 drop of iodine solution and
not the colour.
5. Further, take 2 ml of each solution mixture, mix it with 1 of Fehling
solution (equal volume Fehling A and B). Shake well, warm and note
the colour change if any
(D) Observation:
Tube No.
Colour Produced
With iodine solution With Fehling solution
1 Deep blue Red
2 Deep blue Red
3 Deep blue Red
4 Deep blue Red

11. Experiment :3
Objective: -
To study the effect of temperature on the salivary digestion of starch.
Theory: -
All enzymes, catalysed reaction are sensitive to temperature change and
occur most efficiently around ambident temperature i.e. 303-313 K.
Apparatus requirement: -
Test tube, conical flask, ice bath, two water bath and burner.
Chemical required: -
Starch and 1% iodine solution.
Procedure: -
(A) Collection of Saliva: -
1. Take abaout 20-30 ml of warm distilled water at 313 K in your mouth
Gargle well to mix saliva with distilled water as completely as
possible.
2. Transfer the gargled water in a clear beaker and filter it through a
flutted filter paper into the boiling test tube.
This gives us the required saliva containing the enzymes amalyse or
ptylin.
(B) Preparation of Starch solution: -
2g starch + 10 ml of distilled water boil and filter.
(C) Study of effect of temperature on the salivary digestion of starch: -
1. Take 4 clean test tube and lebel them as 1, 2, 3, 4.
2. Add 10 ml of distilled water, 5 ml of starch solution and 5 ml of saliva
solution to each test tube and shake well.
3. Place test tube no. 1 in ice bath at 273 K, no. 2 at 298 K, no. 3 in water
kept at 303-313K and no. 4 in another water bath containing boiling
water (373K)
4. After 30 min., take one drop of the reaction mixture from each test tube
and place it on a white glazed tile. Mix it with one drop of iodine solution
and note the colour change.
Repeat the exp. after every 30 min. til no colour is formed

12. 5. Take 2 ml of reaction mixture from each test tube and mix with Fehling
solution. Heat and note the colour change. Repeat the exp. after every 30
min. and record the observation as follows: -
Test
tube no.
Colour produced with iodine
solution
Colour produced with Fehling
solution
30 min. 60 min. 90 min. 30 min. 60 min. 90 min.
1 Deep blue Blue Light blue Red
Raddish
red
Orange
2 Deep blue Blue Light blue Red
Raddish
red
Orange
3 Deep blue Blue Light blue Red
Raddish
red
Orange
4 Deep blue Blue Light blue Red
Raddish
red
Orange
Result: -
The above observation suggest that hydrolysis of starch to maltose and glucose by
enzyme ptylin present in saliva is maximum at 308-313 K.