• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

Practical assignment. (1 Viewer)

blacksriders

New Member
Joined
Sep 9, 2008
Messages
6
Gender
Female
HSC
2004
What is the role of the enzyme catalase, it's importance, chemical composition and its specificity ?

The catalase i would be using for this prac, is a potato.



Also .. how do you conduct a prac .. with hydrogen peroxide ?
 

johndownes

New Member
Joined
Jun 20, 2008
Messages
11
Location
Bowral
Gender
Male
HSC
2009
The catalase will break down the peroxide into water and oxygen, causing bubbles. Crush up the potato and put it in the peroxide, and measure how high the bubbles rise.
 
Joined
Sep 26, 2008
Messages
1,948
Gender
Female
HSC
2009
johndownes said:
The catalase will break down the peroxide into water and oxygen, causing bubbles. Crush up the potato and put it in the peroxide, and measure how high the bubbles rise.
yeah thats exactly what we did but we used liver instead of potato
 

jeff.wong

Member
Joined
Oct 27, 2008
Messages
177
Gender
Male
HSC
2008
This is my pract for 2008, maybe it will help...
Change in substrate concentrations on the activity of named enzyme(s)
Aim: To investigate the effect of substrate concentration on enzyme activity.

Hypothesis: The greater the amount of substrate the higher the amount of enzyme activity.

Material:
-Hydrogen peroxide -Pipettes -Ruler
-Distilled water -Fresh potato -Timer
-5 test tubes + rack -Permanent marker

Method:
1. Set up 5 test tubes labelled 1-5.
2. Pipette the volumes of hydrogen peroxide and water as below.
Test tube 1 2 3 4 5
mL H2O2 0 2.5 5.0 7.5 10
mL H2O 10 7.5 5.0 2.5 0
[H2O2 is hydrogen peroxide]
3. Mix the content of teach test tube.
4. Prepare 5 cylinders of potato 8mm diameter and 30mm long.
5. Place potato cylinders one in every test tube.
6. After 5 minute, measure the height of the bubbles of oxygen that form over the contents of the test tubes.
7. Tabulate results.
8. Graph the data using the height of the oxygen as the enzyme activity and record the concentration of the hydrogen peroxide.

Results:
Test tube Bubble height (cm)
1 0
2 1.7
3 1.6
4 1.6
5 2.5

Graph: [I hand drawn the graph]












Discussion:
The bubbles in the test tube popped before the 5 min mark causing the level to drop, this slightly alters the results of the experiment. To improve the experiment 10 test tubes should be used to have more variation and more H2O2 should be used to find the saturation point. The experiment can also be repeated 3 times for an average result with greater accuracy.

Conclusion:
The experiment proved the initial hypothesis was correct therefore hypothesis is accepted. It shows that higher substrate concentration will result in higher enzyme activity.
 
Last edited:

BabyEars

New Member
Joined
Oct 7, 2008
Messages
5
Gender
Male
HSC
2009
The discussion need to be more detailed. Disscussing the vaildity, reliabillity and also including the independant, depandent and control.

Variables that need to be controlled to increase the validity of an experiment, also needs to be included.
 

Kujah

Moderator
Joined
Oct 15, 2006
Messages
4,736
Gender
Undisclosed
HSC
N/A
What is the role of the enzyme catalase, it's importance, chemical composition and its specificity ?

The catalase i would be using for this prac, is a potato.



Also .. how do you conduct a prac .. with hydrogen peroxide ?
Role: Decomposes hydrogen peroxide to water and oxygen in animal and plant cells.
Importance: Metabolic reactions within our body create hydrogen peroxide, which is actually harmful to our bodies. Therefore, it needs to be quickly converted into lesser dangerous products such as water and oxygen.
Chemical composition: will work at its optimum level at a temperature of about 37 degrees and a pH of 7. If you want more in-depth information about its actual structure, search it up :)
Specificity: Will only react with hydrogen peroxide due to the specific shape of the enzyme's active site blah blah.

For the prac, refer to the above posts.
 

x.Exhaust.x

Retired Member
Joined
Aug 31, 2007
Messages
2,058
Location
Sydney.
Gender
Male
HSC
2009
Nice prac Jeff and answers Kujah.

The discussion need to be more detailed. Disscussing the vaildity, reliabillity and also including the independant, depandent and control.

Variables that need to be controlled to increase the validity of an experiment, also needs to be included.
Lol spelling? It's independent and dependent.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top