INVESTIGATORY PROJECT

WORK

Submitted By
Apoorv Mathur
Class: XII Science

Under the Guidance of

Mr.Z.A Ansari
PGT (Chemistry)
 CERTIFICATE

This is to certify that Apoorv Mathur of Class XII

Science has prepared the investigatory
chemistry project entitled “To Study the
digestion of starch by salivary amylase and
effect of temperature and pH on it”. The report
is the result of his efforts & endeavors.
The report is found worthy of acceptance as final
project report for the subject Chemistry of Class XII.
He has prepared the report under my guidance.

(Mr. Z.A Ansari)

(Chemistry)
 CERTIFICATE

The investigatory project entitled

“To Study the digestion of starch by
salivary amylase and effect of
temperature and pH on it”

Submitted by Apoorv Mathur ofClass XII

Science for the C.B.S.E Senior Secondary
Examination class XII of Chemistry
Practical at orchid central has been
examined.

SIGNATURE OF EXAMINER
 DECLARATION

I hereby declare that the project work

entitled
“To Study the digestion of starch
by salivary amylase and effect of
temperature and pH on it”,
submitted to orchid central is
prepared by me.

Apoorv Mathur

Class XII
Science
 ACKNOWLEDGEMEN
T

I would like to express a deep sense of thanks & gratitude to my

project guide Mr.Z.A Ansari Sir for guiding me immensely through the
course of the project. He always evinced keen interest in my work. His
constructive advice & constant motivation have been responsible for the
successful completion of this project.

My sincere thanks go to mrs. Chetna ambetkar , Our principal

maam , for his co-ordination in extending every possible support for the
completion of this project.

I also thanks to my parents for their motivation & support. I must

thanks to my classmates for their timely help & support for compilation
of this project.

Last but not the least; I would like to thank all those who had
Helped directly or indirectly towards the completion of this project.

Apoorv Mathur
Class: XII Science
 CONTENTS

1. Certificate by Teacher. . . . . . . . .
......

2. Certificate by Examiner. . . . . . . .
......

3. Declaration. . . . . . . . . . . . . . . . .
.......

4. Acknowledgement. .. . . . . . . . . .
.......

5. Verification. . . . . . . . . . . . . . . . .

.......

6. Objectives of the Project. . . . . . .

......

7. Introduction. . . . . . . . . . . . . . . . .

......
8. Material Required . . . . . . . . . . . .

......

9. Procedure. . . . . . . . . . . . . . . . . .

.......

10. Observation ................

.......

11. CONCLUSION. ...............

......

12. BIBLIOGRAPHY. . . . . . . . . . . . . . .
......
 Objectives of the Project Report

The main objective of this chemistry

project report is “To Study the
digestion of starch by salivary
amylase and effect of
temperature and pH on it”and

1) To study digestion of starch by saliva.

2) To study the effect of temperature on the
digestion of starch by saliva.
3) To study the effect of pH on the salivary
digestion of starch.
Introduction
Every Health book insists on the chewing of food. The act of
chewing stimulates the excretion of saliva. Saliva mixes up with
the food and helps its digestion. That is, the enzyme ptyalin or
amylase present in human saliva hydrolyzes the big molecules
of food into many molecules. For example starch into mono-
saccnaricies maltose and glucose; proteins into amino acids and
fats into fatty acids and glycerol. Thus saliva not only helps in
digestion of food but convert it into energy generating
substances. Further, enzymes and their activity are very
sensitive to temperature and ph. Even a slight variation in these
two factors, can disturb the action of enzymes. In other words,
digestion of food by salivary amylase is also effected by pH and
temperature and can be verified experimentally. For example,
hydrolysis of starch can be verified by testing it with iodine
solution. Starch forms blue coloured complex with iodine. If no
starch is present in a system it will not give blue colour with
iodine.
 Material Required

The requirements for experiment of

Chemistry Project Report are as
under:

1) Test tubes

2) Test tube stand

3) One dropper

4) Beaker

5) Stop watch

6) Starch and Iodine solution

7) Thermometer

8) Dilute HCL and Dilute NaOH solution.

 Chemistry Experiment 1 Procedure

Procedure for Chemistry Experiment 1 is:

1) Collection of Saliva– Rinse mouth throughly with

cold water and ensure that it does not contain any food
particles. Now take about 20ml of lupe warm water in
the mouth and gangle for about three minutes so that
saliva mixes up well with it. Spit this into a beaker.
Filter, if there is any suspended impurity clear filtrate is
saliva solution and contains enzyme ptyalin.
2) Preparation of starch solution – Take about 0.5g
of starch in 100ml beaker and add enough water to make
a paste. Dilute the paste by adding 50ml water and boil
for about 5 minutes.
3) Digestion of starch :-
(a)Take 5ml of the starch solution in a test tube. Add 2ml
of saliva solution into it. Mix the solutions well by
shaking the tube carefully and start a step watch.
(b) After one minute take out two drops of the mixture
solution from the test tube with the help of a dropper
and transfer it into another test tube containing about
one 1ml of 1% iodine solution. Note the colour
produced, if any.
(c)Repeat this test after every one minute taking two
drops of the mixture solution and fresh 1% iodine
solution continue until the test shows no blue colour.
Record the time and blue colour intensity.
 Observation

Time Passed 1 2 3 4
after Mixing Minute Minute Minute Minute
Colour Deep Blue Light No Blue
Intensity Blue Blue

Absence of blue colour on addition to iodine solution

means absence of starch in the mixture solution. That is
whole of the starch has got digested or hydrolysed.
Chemistry Experiment 2

Procedure: -Effect of temperature on the

digestion of starch
by saliva.

1) Take three test tubes and label these 1, 2, and 3.

2) Take 5ml of the starch solution, 2ml of the saliva solution
and 5ml of water in each test tube.
3) Place test tube Number 1 in water at room temperature, test
tube Number 2 in a beaker containing water at 500 C and
test tube Number 3 in boiling water.
4) After 5 minutes, observe the colour change on mixing two
drops of the mixture of every tube with one ml of 1%
iodine solution. Note the intensity of blue coloured form.

Conclusion

Starch get hydrolysed by saliva amylase

Chemistry Experiment 3

Procedure: - To study the effect of pH on

the salivary
digestion of starch

1) Take three test tubes and label these 1, 2, and 3.

2) Add 5ml of the starch solution, 2ml of the saliva
solution in each test tube.
3) Now ass 2ml of water in test tube Number 1 2ml of
Dilute HCL in test tube Number 2 and 2ml of Dilute
NaOH solution in test tube Number 3 and shake
carefully.
4) Keep the three test tubes in water at room temperature
for about 10 minutes.
5) Add 2 drops of the solution of each test tube with 1%
iodine solution and observe the colour change

Conclusion

Temperature effects the digestion of starch by salivary

with increase in temperature salivary amylase get
inactivated and process of digestion do not take place.
BIBLIOGRAPHY
1 http://www.google.com/

2 http://en.wikipedia.org

3 N.C.E.R.T Class 12 Chemistry

4 Dinesh Chemistry

5 Comprehensive Chemistry