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BIO prac (1 Viewer)
- Thread starter Bellow
- Start date
The_highwayman
Banned
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- Oct 27, 2004
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- 2005
A junket tablet contains the enzyme rennin (a stomach enzyme found in many mammals) which causes the milk protein to coagulate.
elisabeth
Member
If you don't want to use that one, the prac our class did with liver and catalase was pretty easy.... or you can get the info about your prac from here
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Aim: to investigate the effect of temperature on enzyme activity.
Hypothesis: an enzyme will have a specific temperature at which it functions best.
Equipment:
5 test tubes
5 sticky labels
Test tube rack
Liver (source of enzyme catalase)
Hydrogen peroxide (H2O2)
5 water baths
Thermometer
Ruler
Stopwatch
Method:
1. Set up apparatus: Place 10ml hydrogen peroxide in each test tube. Label one 15, another 35, another 55, another 75 and one 95.
2. Check temperature of each water bath. They should be 15, 35, 55, 75 and 95 degrees respectively.
3. Place a test tube in respective water bath.
4. Add a small piece (about 1.5x1.5cm) of liver to each test tube.
5. Observe rate of reaction in each tube.
6. Record observations (bubbling, fizzing etc.) and measure height of bubbles produced, which gauges rate of reaction (so hence enzyme activity).
7. Remove test tubes after 3 minutes.
Method 2: (to prove enzymes can be denatured by extreme conditions)
1. Place all test tubes in water bath at 35 degrees.
2. Observe which tubes' contain a reaction. Tube 15 and Tube 35 will be, Tube 55 may be but not as great a reaction and Tube 75 and Tube 95 will not have a reaction.
Results:
- Enzyme activity was optimum at 35 degrees.
- V. sharp increase + decrease either side of this temperature (can't find actual figures, sorry)
- No reaction above 75 degrees - enzyme has been denatured. So temperatures less than optimum don't cause structural damage to enzyme, although their rate of reaction isn't as great. However, temperatures too far above the optimum (60 degrees and over for catalase, I think) cause a permanent change to the enzymes structure by breaking its bonds (peptide, I think) and destroying the active site. The enzyme has been denatured and hence it can't catalyse any more reactions.
Risks: Take care with water baths at hot temperatures.
Justify: A reliable source of catalase (liver) was used. Other variables such as pH and substrate concentration were kept the same. Experiment was repeated following week to ensure accuracy through repetition.
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Aim: to investigate the effect of temperature on enzyme activity.
Hypothesis: an enzyme will have a specific temperature at which it functions best.
Equipment:
5 test tubes
5 sticky labels
Test tube rack
Liver (source of enzyme catalase)
Hydrogen peroxide (H2O2)
5 water baths
Thermometer
Ruler
Stopwatch
Method:
1. Set up apparatus: Place 10ml hydrogen peroxide in each test tube. Label one 15, another 35, another 55, another 75 and one 95.
2. Check temperature of each water bath. They should be 15, 35, 55, 75 and 95 degrees respectively.
3. Place a test tube in respective water bath.
4. Add a small piece (about 1.5x1.5cm) of liver to each test tube.
5. Observe rate of reaction in each tube.
6. Record observations (bubbling, fizzing etc.) and measure height of bubbles produced, which gauges rate of reaction (so hence enzyme activity).
7. Remove test tubes after 3 minutes.
Method 2: (to prove enzymes can be denatured by extreme conditions)
1. Place all test tubes in water bath at 35 degrees.
2. Observe which tubes' contain a reaction. Tube 15 and Tube 35 will be, Tube 55 may be but not as great a reaction and Tube 75 and Tube 95 will not have a reaction.
Results:
- Enzyme activity was optimum at 35 degrees.
- V. sharp increase + decrease either side of this temperature (can't find actual figures, sorry)
- No reaction above 75 degrees - enzyme has been denatured. So temperatures less than optimum don't cause structural damage to enzyme, although their rate of reaction isn't as great. However, temperatures too far above the optimum (60 degrees and over for catalase, I think) cause a permanent change to the enzymes structure by breaking its bonds (peptide, I think) and destroying the active site. The enzyme has been denatured and hence it can't catalyse any more reactions.
Risks: Take care with water baths at hot temperatures.
Justify: A reliable source of catalase (liver) was used. Other variables such as pH and substrate concentration were kept the same. Experiment was repeated following week to ensure accuracy through repetition.
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