LAB Report Digestion OF Starch (BIO270) PDF

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Universiti Teknologi MARACawangan Perak Kampus TapahFaculty of Applied SciencesDiploma in ScienceBIOLABORATORY REPORTEXPERIMENT : 4. DIGESTION OF STARCH IN HUMANSDATE OF SUBMISSION :GROUP : AS1203BGROUP MEMBER:NO. STUDENT’S NAME STUDENT ID.1.2.3.PREPARED FOR :Assessment: Introduction 1 0 0 0 0. Proc...

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Assessment: Introduction Procedure Data/Results Discussion/Calculations / Analysis/Evaluation Conclusion Total

1.0 1.0 3.0

0.8 0.8 2.4

0.6 0.6 1.8

0.4 0.4 1.2

0.2 0.2 0.6

4.0

3.2

2.4

1.6

0.8

1.0

0.8

0.6

0.4

0.2

Universiti Teknologi MARA Cawangan Perak Kampus Tapah Faculty of Applied Sciences Diploma in Science BIO270

LABORATORY REPORT

EXPERIMENT

: 4. DIGESTION OF STARCH IN HUMANS

DATE OF SUBMISSION

:

GROUP

: AS1203B

GROUP MEMBER: NO.

STUDENT’S NAME

1. 2. 3.

PREPARED FOR

:

STUDENT ID.

OBJECTIVES: 1.To inspect the hypothesis that saliva contain an enzyme which break down the starch to sugar. 2. To investigate the properties of the enzyme and the conditions under which it works most effectively. HYPOTHESIS: Saliva contains an enzyme, amylase which break down starch to sugar. INTRODUCTION: Starch is a polysaccharide which has to be broken down into free sugar molecules before absorption can take place. Starch is mixed with saliva under various conditions and after a given period of time the mixture is tested for starch with iodine solution and for sugar with benedicts reagent. In this experiment, an investigate the role of amylase in food digestion by using breakdown of starch from polysaccharide to monosaccharide in reducing sugar form. MATERIALS -

Test tubes

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Test tubes rack

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Measuring cylinder

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Water bath

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Bunsen burner with tripod and gauze

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Starch

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Sugar

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Iodine solution

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Benedict’s reagent

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Hydrochloric acid

PROCEDURE : 1. 20 cm3 of uncontaminated saliva collected in a measuring cylinder : the flow can be increased by chewing paraffin wax. 2. The saliva could not be produced in 20 cm3 , it can be made in 10 3 cm and all subsequent quantities and reagents divided. 3. One quarter of saliva been transferred to a test tube and been placed in a boiling water bath for 15 minutes. 4. A further quarter transferred to another test tube and 4 drops of hydrochloric acid added (1mol dm−3 ) mixed well and had been leave for 15 minutes. 5. The six pairs of the tubes been set up as follows, and each tubes labelled with code number which were ; for iodine test ; 1mL sugar (I1), 1mL starch (I2), 1mL untreated saliva (I3), starch+2mL untreated saliva (I4), starch + 2mL preheat saliva (I5), and 1mL starch + 2mL acidified saliva (I6) while for benedict test; 1mL sugar(B1), 1mL starch (B2), 1mL untreated saliva (B3), 1mL starch + 2mL untreated saliva (B4), 1mL starch + 2mL preheat saliva (B5) and 1mL starch + 2mL acidified saliva (B6). 6. The test tubes had been leave for 10 minutes before proceeding further. 7. The contents of each pair of test tube had been tested which for starch , two drops of iodine solutions added while for sugar, with one-eight test tube of Benedict’s reagent heated. 8. Did the starch test on the first of each pair of test tube, and the sugar had been tested on the second of each pair. 9. The test tubes arranged in the rack in numerical order to facilitate comparison. 10. The colour changes recorded. Which the test tubes show positive results and which ones show negative results for each starch and sugar contents will be indicated.

DATA:

Image (i) : Iodine Test

Image (ii) : Benedict’s Test

RESULT TABLE 2 : ENZYME REACTIONS FOR SUGAR AND STARCH

TEST TUBE LEVEL PAIR 1 A 2 PAIR B

PAIR C

No change

4mL sugar only

Blue to brick-red

3

4mL starch only

4

4mL starch only

Yellow to blueblack No change

5

4mL untreated saliva only 4mL untreated saliva only 4mL starch plus 2mL untreated saliva only 4mL starch plus 2mL untreated saliva only 4mL starch plus 2mL pre-heated saliva only 4mL starch plus 2mL pre-heated saliva only 4mL starch plus 2mL acidified saliva 4mL starch plus 2mL acidified saliva

7

8

PAIR E

9

10

PAIR F

OBSERVATION

4mL sugar only

6 PAIR D

CONTENT

11

12

CONCLUSION

Yellow to lightblue

No presence of starch Presence of sugar Presence of starch No presence of sugaro No presence of starch No presence of sugar Presence of starch

Blue to yellowgreen

Presence of sugar

Yellow to blue

Presence of starch

No change

No presence of sugar

Yellow to blueblack

Presence of starch

No change

No presence of sugar

No change No change

DISCUSSION: The objectives of this experiment are to inspect the hypothesis that saliva contain an enzyme which break down starch to sugar and to investigate the properties of the enzyme and the conditions under which it works most effectively. In this experiment, starch is mixed with saliva under various conditions and after a given period of time the mixture is tested for starch with iodine solution and for sugar with Benedict’s reagent. The name of the enzyme in saliva is amylase which breaks down the starch into glucose or sugar. When enzyme bind with starch, it will break down the starch structure and form glucose. At this time, this reaction was completely reacts. The test tubes with pure sugar, starch and untreated saliva in this experiment are used as indicator. The purpose of testing test tubes 1 to 6 is to test the presence of the starch and the presence of sugar. Based on the observation in pair A test tubes, only solution in test tube 2 turn from colorless to brick red confirming the presence of sugar. In pair B test tubes, solution in test tube 3 turn from colorless to blue-black showed the presence of starch while in test tube 4 no reaction occurred. No reaction occurred in both test tube 5 and test tube 6 of Pair C test tubes. In this experiment, test tube 7 and 8 are used to test the hypothesis that saliva contains an enzyme which breaks down the starch to sugar. These tubes are the untreated saliva that contain active enzymes which can breaks the starch, so it is easier to analyse. Test tube 11 contain pre-heated saliva which the enzyme in the saliva has been denatured because of the high temperature. So, that is why no sugar is detected in test tube. Test tube 12 contain acidified saliva which also showed that the enzyme is denatured because of the pH value. Most of the enzyme work best at pH value of 7 to 7. The hydrochloric acid in the test tube makes the enzyme denatured. As a conclusion, the hypothesis for this experiment turn out to be correct and it can be accepted. It was proven that the saliva contains an enzyme, amylase that can breaks down starch to sugar. Enzyme is a type of protein which can be affected by the temperature and pH value. Hypothesis is accepted.

CONCLUSION: As a conclusion, we can conclude the hypothesis that saliva contain an enzyme,amylase which breaks down starch to sugar.Enzyme is a type of protein which can be affected by the temperature and pH values, it show that these enzymes works most effectively under temperature which is 37.5 degree Celsius and PH 7.Hypothesis is accepted. REFERENCES: 

2019,Royal society of biology,Naoroji street,London OGB Registered charity, retrieved from https://rsc.org/education/teachers

 Cornell, B. 2016. Referencing. [Accessed 18 October 2018], retrieved from http://ib.bioninja.com.au.  Iain A. Brownlee Saloni Gill Matt D. Wilcox Jeff P. Pearson Peter I. Chater. First published: 31 August 2017, retrieved from https://doi.org/10.1002/star.201700111  Royal Society of Chemistry: Chemistry for Biologists: Enzymes, accessed October 2011, retrieved from https://pbiol.rsb.org.uk/bio-molecules/factors-affecting-enzymeactivity/investigating-the-effect-of-ph-on-amylase-activity...