BIOLOGY REPORT

PRACTICUM OF CATALASE ENZYME

Teacher:

Dra Hj Anik Silfi W.

Group Member of Practicum :

Alfan Zuhrifan (01)

Devi Shofia Al Fitri (06)

Ines Almanda Kartika (18)

M. Alfian Irsyadul Ibad (21)

Nuzula Fikrin Nabila (24)

Yella Apriliana Sa’diyah (31)

SMA NEGERI 1 BOJONEGORO

ACADEMIC YEAR 2012/2013

PLACE AND DATE OF PRACTICUM:Date : Monday September 3rd 2012Place               : SMAN 1 BOJONEGORO’s biology laboratory

PURPOSE1. Observe the role of the enzyme catalase2. Observe the factors that influence the enzyme’s activity3. Know and understand the reaction of the chemical reactions that occur in the enzyme

catalase test

TOOLS AND MATERIALS

1. Reaction tube rack

2. Chicken liver extract

3. Reaction tube, Beaker, Pasteur pipette, burner spiritus, 4. H2O2

5. HCl

6. NaOH

`Tripod and gauze

7. Water 8. Ice cube

9. Sticks and matches10. Tube clamp11. A pestle set

METHOD TO WORK

1. Setting up a stick and lit the burners spritus2. Filling a test tube with water and heat on burners spritus

3. Pound chicken livers4. Giving water on chicken livers

5. Filtering chicken livers that are mixed with water6. Put chicken liver extract into each test tube (5 test tubes), label to each tube of A until E

7. In tube A Drops 2 drops of H2O2 into a test tube containing chicken liver and immediately closed it with our thumb

8. Observing the number of air bubbles formed (much all = + + + +, many = + + +, + + = moderate, + = slight, no = -)

9. Put sticks into the embers of a reaction tube quickly, observe the flame embers

10. In tube B before spilled H2O2, HCl solution used as drops 2 drops, and let some time was

given H2O2, observe what happens

11. In tube C before spilled H2O2, NaOH solution used as drops 2 drops, and let some time was given H2O2, observe what happens

12. On the tube D before spilled H2O2, first reaction tube that has been heated by the activity 1, then put H2O2 after any changes observed then Enter smoldering embers of sticks into the test tube quickly, observe what happens

13. On the tube E before spilled H2O2, first reaction tube immersed in a pile of ice cubes until completely cold, then enter H2O2, having observed what changes later

14. Enter the smoldering embers of the stick into the reaction tube quickly, observe what happens

15. Observations noted in the table

16. Washing and cleaning reaction tube and tools that have been used

RESULTS OF OBSERVATIONSIn the chicken liver

Treatment Bubble Entered embers

Extract H2O2 + + + + Burning

Extract+ HCl + H2O2 - Not lit (dim off)

Extract + NaOH + H2O2 + + + Do not turn on (dead rather dim)

Extract + H2O2 (was boiled) - Not on (death)

Extract + H2O2 (was cooled) + + + Burning

Description:+ + + + = Very much bubble+ + + = Many bubbles

+ + = Moderate bubble+ = Slight bubble- = No bubbles

DISSCUSSION

Enzymes are catalysts made of protein produced by cells. The enzyme has a specific nature that is just catalyzed certain chemical reactions. For example, the only enzyme catalase H2O2 decompose into H2O and O2 by the reaction as follows:

2H2O2 ==> 2H2O + O2

This can be proved by experiment. The experiment was performed using chicken liver. Chicken liver is used because it contains the enzyme catalase. What happens when the extracts were treated as follows:

Extract plus H2O2 (hydrogen peroxide)

When the extracts were H2O2 occurred bubbles that much, this proves that the catalase enzyme present in the liver of chicken change H2O2 to H2O (water), whereas at the time put a burning stick into it, flames arise. This proves that H2O2 is also broken down into oxygen (O2).

Extract plus HCl and H2O2 Added HCl here in is intended to make the extract in an overly acidic. Then added H2O2

was not formed air bubbles when put hot coals in it did not happen flame. This suggests that the enzyme catalase can not work in conditions too acidic.

Extract plus NaOH and H2O2

The addition of NaOH herein is intended to make the state too alkaline extract. Then added H2O2 turns air bubbles are formed, but when the embers put into it is not going flame. This proves that the enzyme catalase can not work optimally in conditions too alkaline.

The extract is boiled and then added H2O2 Extracts were boiled and then added H2O2, did not arise when air bubbles and embers put

into it also does not arise flame. This is because the protein in the catalase enzyme present in the extract has been damaged so it can not decompose H2O2 to H2O and O2.

The extract is cooled and then added H2O2Extracts were cooled and then added H2O2, air bubbles and turns arise when embers put

into it apparently arising flame. This is because the protein in the catalase enzyme present in the extract, it still is not as active as in cool, because at low temperatures causes the enzyme to be active

CONCLUSIONThe enzyme catalase works by decomposing H2O2 to water (H2O) and oxygen (O2). Catalase enzyme will break down when working at high temperatures, and in acidic or alkaline. And in active when working at low temperatures.

SUGGESTION1. It takes more time, and time specific (outside school hours) for this experiment so that we more closely and intensively testing the factors that influence the action of the enzyme.2. Needed tools - tools to make the data more complete our experimental results more accurate.