THE EFFECT OF AMYLASE ON A STARCHY FOOD

DEPARTMENT OF BIOLOGY

FACULTY OF SCIENCE & MATHEMATICS

UNIVERSITI PENDIDIKAN SULTAN IDRIS

SBK3013

PRINCIPLE IN BIOCHEMISTRY

LABORATORY PROJECT 2

ENZYME: THE EFFECT OF AMYLASE ON A STARCHY FOOD  

NAME	MATRIC NO.
MUHAMMAD FARIS BIN ISMAIL SAZEMI	D20141067089
MAYURIE PHUTHARANT A/P SURIN	D20141067078
NUR AFIQAH SYAHMINA BT MOHD KAMAL	D20141067091

GROUP: A

LECTURER’S NAME: DR. ROSMILAH MISNAN

INSTRUCTOR NAME: NUR ATIEKAH BT AZAHARI

INTRODUCTION

          All living beings need energy to survive. It is from the food we consume that we get our energy. We know that the energy we are getting is by the process of digestion that breaks down the complex substance of starch into simpler molecules of glucose, which are further metabolized into CO2 and water through the process of glycolysis. The human digestive tract starts at the mouth and ends at the anus.

          In the beginning, the digestion of the food starts as soon as we put food in our mouth. Our teeth cut the food into small pieces and the salivary glands secrete saliva that mixes with these food materials. The saliva contains an enzyme called salivary amylase which hydrolyses starch into maltose. The complete digestion of starch occurs only in the small intestine by the action of pancreatic amylase.

MATERIAL

• ·         Starch foods – rice
• ·         Boiling tubes
• ·         Test tubes
• ·         Visking tubes
• ·         Elastic bands
• ·         Dimple tile
• ·         Thermometer
• ·         Beaker containing water at 37⁰C
• ·         Large beaker of boiling water

PROCEDURE

1.      Three boiling tubes was labelled as 1, 2 and 3

2.      3 model guts was set up using visking tube and tie a knot at the end of the visking tube. 

1.      The starchy food was added into the each of the model gut until half full

2.      Visking tube was been place under running tap.

3.      The model guts placed into boiling tube

4.      Use an elastic band to make sure it did not split.

5.      25 ml of  warm water added into the boiling tube 

1.      5 ml of water was added into model gut 1, 5 ml of amylase was added into model gut 2 and 5 ml of treated amylase into model gut 3.

2.      All the boiling tubes that containing model gut was placed into a beaker that containing water at 37⁰C.

3.      30 minutes time set for incubation.

1.      During waiting, iodine test and benedict test was conducted

·         For the iodine test, some of starchy food was added into white tile and a drop of iodine was added.

·         For the benedict test, starchy food was added into test tube with 2 ml of water, 2 ml of benedict reagent and then test tube was placed into beaker containing boiling water.  After 2-3 minutes the colour changes was recorded. 

1.      After 5 minutes incubation, the iodine test and benedict test was repeated for both water in the gut model and water in the boiling tube, as below;

·         The water from model gut 1 and water surrounding the model gut in boiling tube 1 was take some and placed in the white tile. Then added one drop of the iodine into the solution. The result was recorded.

·         2 ml of the water from model gut 1 and 2 ml of water in the boiling tube and placed each into test tube. Then 2 ml of Benedict reagent was added into each test tube and then placed the test tube into beaker containing boiling water. After 2-3 minutes the colour changes was recorded.

2.      Step 12 was repeated every 5 minutes until 30 minutes.

3.      Step 11 to 13 was repeated with water from gut models and boiling tube 2 and 3.

 RESULT

Time/Tube	Boiling tube 1 (Water)		Boiling tube 2 (Amylase)		Boiling tube 3 (Treated amylase)
	Inside	Outside	Inside	Outside	Inside	Outside
5 mins	solution turns aqua blue	solution turns aqua blue	solution turns aqua blue	solution turns aqua blue	solution turns aqua blue	solution turns aqua blue
10 mins	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged
15 mins	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged
20 mins	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged
25 mins	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged
30 mins	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged	Aqua blue solution remains unchanged

1.      Benedict’s test

2.      Iodine’s test

	Boiling Tube 1 (Water)	Boiling Tube 2 (Amylase)	Boiling Tube 3 (Treated amylase)
5 mins	Solution turns dark blue	Solution turns dark blue	Solution turns dark blue
10 mins	Solution turns dark blue	Solution turns dark blue	Solution turns dark blue
15 mins	Solution turns dark blue	Solution turns dark blue	Solution turns dark blue
20 mins	Solution turns dark blue	Solution turns dark blue	Solution turns dark blue
25 mins	Solution turns dark blue	Solution turns dark blue	Solution turns dark blue
30 mins	Solution turns dark blue	Solution turns dark blue	Solution turns dark blue

 DISCUSSION

From the Benedict’s test experiment, we obtained that all the solution remains aqua blue solution although being left for 30 minutes. There are no further changes in the experiment. In lab, we used Benedict's reagent to test for particular reducing sugar which is glucose. Benedict's reagent starts out aqua-blue. If it is heated in the presence of reducing sugars, it will turns yellow to orange. Boiling tube 1(insert with water) boiling showed the absence of sugar inside and outside the Visking tube due to no enzyme presence in water and the starch molecules are too large to pass through the holes in the Visking tubing. Boiling Tube 3 (insert with treated amylase) also showed absence of sugar inside and outside the visking tube. This is due to the treated amylase cause the enzyme to be denatured and unfunctionally hence the enzyme amylase are not able to break down some of the starch to sugar. Thus no sugar presence. Theoretically, it should be changes showed in Boiling tube 2 (insert with amylase). Benedict’s solution will turn from aqua blue to yellow to orange. This is because the enzyme amylase will be broken down some of the starch to sugar and some of the smaller sugar molecules will be able to pass through the holes in the Visking tubing. But in this experiment we obtained negative result. There are no presence of sugar outside and inside the visking tube. There is error occur due the heat provided do not reach optimum temperature for amylase enzyme to function optimumly. And there are some heat loss to the surroundings.

The iodine test is used to test for the presence of starch. When treated with IKI solution—iodine dissolved in an aqueous solution of potassium iodide—the triiodide anion (I3−) complexes with starch, producing an intense blue/purple colour. For Iodine’s test, solution in boiling tube 1 turns iodine to dark blue solution. When starch is mixed with iodine in water, an intensely blue colored starch/iodine complex is formed. For solution from Boiling Tube 3 also, indicate that there are starch presence hence the iodine solution turn dark blue. This is due to starch are not being broken by enzyme amylase into sugar. Treated amylase inhibit the enzyme to function optimumly in other to convert starch to sugar. Solution from Boiling Tube 2 also dark blue colored changed in iodine. Theoretically, in Boling Tube 2 starch will be broken down into sugar due to reaction with enzyme amylase hence the iodine color will be brown-yellow color (iodine solution color). But in our experiment, the solution turns to dark blue solution indicate that there are starch presence. We believed that this due to some error during the experiment because the dropper used to move solution from the tube 2 to the tile are using repeatedly from dropper used for Boiling Tube 1 and Boiling 3 hence the starch are not cleanse thoroughly.

QUESTION AND ANSWER

1.      What does the Visking tubing of the model gut represent?

The Visking tubing of the model gut represents the wall of the small intestine.

2.      What does the water in the boiling tube, outside the model gut, represent?

The water in the boiling tube outside the model gut represents blood in the blood vessels around the intestine.

3.      How is this model different from the situation in a real gut?

In a real gut, food is moving through the tube, blood is circulating around the blood vessels and carrying away the absorbed food chemicals, the gut lining is folded into villi and microvilli, there are mechanisms that can actively absorb some food chemicals, there is a more complicated mixture of food and enzymes in the intestine, the pH of the gut contents is controlled by gut secretions etc.

4.      What has happened to the starch in each of your tubes?

There are no starch at outside the gut model this because the starch molecule itself is bigger so it cannot pass through the gut model.

5.      What has happened to sugars (detected with Benedict’s reagent) in each of your tubes?
      In tubes 1 and 3, there is no sugar either inside or outside the gut. In tube 2, there is sugar inside and outside the gut.

6.      Why does the body need enzymes to digest food?

The body needs enzymes to digest food because large polymer food molecules are too large to pass through the gut wall. Chemical digestion without catalysts is too slow to be useful. Specifically, we need glucose (and other sugars) as a ready source of energy in our bloodstream.

7.      What is your result with treated amylase? Explain

From the result that obtain for treated amylase, the colour for treated amylase are dark blue colour. This happened because the treated amylase degrade the starch produced of short chain. This show that treated amylase show a positive result of starch in rice.

CONCLUSION

The Benedict’s test is meant for the testing for particular reducing sugar which is glucose meanwhile, iodine test is test for the presence of starch.

REFERENCES

Katherine J. Denniston, Joseph J. Topping, Kim R. Woodrun, Robert L. Caret.(2013). General, Organic and Biochemistry.  United State of America: McGraw-Hill Education

Martin S. Silberberg (2013). Chemistry: The Molecular Nature of Matter and Change. New York: McGraw-Hill Companies Inc.