Enzyme Concentration Lab Report
Affect of enzyme concentration to the rate of reaction
Aim:
With the experiment of protein solution, in this case egg white added to different pepsin concentrations (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%) shows, as the egg white is a protein and the pepsin works as an enzyme, how a higher pepsin concentration and therefore a larger amount of enzymes effect the rate of reaction.
Hypothesis:
An increased concentration of pepsin speeds up the time the mixture needs to come clear.
Introduction:
The egg white is our protein solution, because egg white is a typical protein with peptide bonds between its amino acids that can be broken by pepsin, a metabolism enzyme that works best under a pH between 1 and 5, and is destroyed at a pH of 6. Enzymes …show more content…
are proteins that work as biological catalysts to reduce the required activation energy to start a reaction. This allows reaction to happen even at lower temperatures than they actually need. Too high temperatures as well as the wrong pH can destroy the active side of an enzyme that is appropriate for the break down of substrates into products. That ability can make poisonous substrates and molecules harmless, because they are separated into two products, who then can be used for different things in the body. The active side on an enzyme has a specific shape which allows the joining with just one specific molecule. Therefore a lot of different enzymes with different fields of duties are in the body. First the key and lock theory explained the joining of the active side with a fitting substrate but after more study scientists agreed that this theory isn`t that likely because enzymes are even more specific and have to make sure that the molecule that connects with their active side is definitely the one that they are able to break down.
A new theory, the induced fit model, assume that as soon as the substrate sticks to the active side of an enzyme and forms the enzyme/substrate complex, the active side changes slightly its shape and sticks even closer together with the substrate to insure that they fit together.
As more enzymes are in a solution, the higher is the rate of reaction. This is because more active sides are available and ready to join together with the other molecules in the solution. Substrates can therefore faster find a fitting active side and be broken down. With keeping the amount of enzymes increasing, it will stop having any affect of the rate of reaction, as soon as all the limited molecules of the solution found their active side.
[pic] [pic]
A pepsin molecule an egg white protein molecule
[pic]
Induced fit model – substrate broken down
Variables:
The constant factor was the amount of egg white solution (5cm3) in our six test tubes, the temperature and the pH of the enzyme solution. Therefore the six different concentrated pepsin solutions (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%) are the independent factor with effects the dependent factor, the rate of reaction or the time till the mixture gets clean.
Equipment:
|Apparatus/ Equipment |Justification |
|Egg white solution |Typical protein with peptide bonds |
|Test tubes |-easy to separate the different mixtures |
| |-good overview when a solution gets clear |
|Labels |-to identify which concentration got clear when |
|Test tube holder |-holds the test tubes |
| |-makes it easy to compare the clearness of the solutions |
|Stop clock |-to notice the time, when a solution gets clear |
|Pepsin solution (to make 0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0% |-to compare the effect of different amount of enzymes in egg white |
|concentration of enzymes) |-pepsin solution contains enzymes that are able to break down egg |
| |white’s peptide bonds |
|5cm3 pipettes, syringe |-fair test/ valid results |
| |-protein solution must be in every test tube exactly the same to |
| |make sure that the effect of enzymes wont be influent by anything |
|Cylinder |-fair test/ valid results |
Risk Assignment:
|Hazard |Risk |Control |Action |
|Glass equipment |Breakages |Use test tube racks and tongs to |Remove broken glass with dustpan |
| | |prevent glass rolling of bench |and brush in place in broken glass|
| | | |bin |
|Swallow or drink of substance |Can get poisoned |Don`t drink or swallow any |Seek medical attention |
| | |substance.
| |
| | |Warn your classmates | |
|Spillages |Slip and fall |Use test tube racks and tongs to |Inform the teacher
|
| | |transfer liquid | |
|Electricity and water |Electric shock |Do not work with water close to |Switch off the electricity. |
| | |any electricity |Seek medical attention and try to |
| | | |accord first aid if necessary |
Method:
1. We labelled 6 simple test tubes with the concentrations of pepsin, we were about to put in
(0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%)
2. With a pipette we pour 5cm3 of egg white solution in every test tube
3. From a big bowl with pepsin solution, we again used the pipette to make different concentrations of pepsin solution. Therefore we took for the first test tube no pepsin solution and 10cm3 of the egg white (0% solution), the next test tube was filled with 2cm3 of pepsin and the left 8cm3 were egg white solution. We continued this procedure for the left 4 test tubes.
4. As soon as we added the pepsin solution to the egg white, we mixed them thoroughly and started the stop watch.
5. In the test tube holder, we watched the 6 test tubes and record the time and the amount of pepsin concentration when one of them got clear.
Results:
[pic] [pic]
All at the same time
0% of pepsin: 0.2% of pepsin: 0.4% of pepsin: 0.6% of pepsin:
[pic] [pic] [pic] [pic]
0.8% of pepsin: 1.0% of pepsin:
[pic] [pic]
Result in form of tables:
|Acidified |Concentration |Time Taken (min) to turn clear |
|Pepsin |Of Pepsin | |
|Solution | | |
| | |Trial 1 |Trial 2 |Trial 3 |Trial 4 |Average |
| |0% |NC |NC |NC |NC |NC |
| |0.2% |12.4 |16.9 |15.05 |6.8 |12.7 |
| |0.4% |7.51 |17.21 |4.2 |4.25 |8.29 |
| |0.6% |3.35 |6.01 |3.5 |3.45 |4.07 |
| |0.8% |1.58 |5.53 |3.4 |3.0 |3.37 |
| |1.0% |0.5 |0.52 |0.26 |0.48 |0.44 |
[pic]
[pic]
[pic]
[pic]
[pic]
Justification:
The fact that we repeated our experiment more than once, gives us a good average to proof the hypothesis. Also the measuring with pipettes to insure that all test tubes contain the same amount of white egg solution makes it more valid.
Every trail showed the same trend, which is once more represent in the average of all 4 passes. The lowest concentration of pepsin needed the most time to come clear, whilst the highest amount speeds up the process of coming clear. Still there are differences and errors. The exceptional value in trail 2 of 17.21 min at the 40% concentration that is higher than the 20% concentration time (16.9) that was required to make the solution coming clear, may be a random error. Faults could have happened at stopping the stop watch correctly or having a slightly different of egg white solution in that test tube.
In general a systematic error could have been the different definition of a “clear solution”. Although the trials show the same tendency, the values are arranged in different heights. While one pair might have said the solution is clear when it still got a dusty colour, another pair might have wait till the solutions are completely clear and they therefore needed more time with every concentration.
To improve the experiment an official definition of “clear” must be arranged. Also mistakes in measuring must be avoid by being as exact as possible and making sure that no solution is left in the pipettes and syringes that changes the actual amount of solution we work with in the test tubes. In general the experiment could be more valid when we repeat it more than 4 times.
Conclusion:
In spite of little mistakes and differences, especially the average graph shows a negative correlation between time that is required to make the solution clear and concentration of pepsin. As higher the pepsin concentration of the solution is, the slower the solution gets clear. That supports our hypothesis because the larger amount of enzymes in our high concentrated pepsin egg white solution increases the rate of reaction by provide more active sides that can join to an enzyme/substrate complex with the egg white protein molecules and break them down, what for our eyes clears the previous milky solution.
Aim:
With the experiment of protein solution, in this case egg white added to different pepsin concentrations (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%) shows, as the egg white is a protein and the pepsin works as an enzyme, how a higher pepsin concentration and therefore a larger amount of enzymes effect the rate of reaction.
Hypothesis:
An increased concentration of pepsin speeds up the time the mixture needs to come clear.
Introduction:
The egg white is our protein solution, because egg white is a typical protein with peptide bonds between its amino acids that can be broken by pepsin, a metabolism enzyme that works best under a pH between 1 and 5, and is destroyed at a pH of 6. Enzymes …show more content…
are proteins that work as biological catalysts to reduce the required activation energy to start a reaction. This allows reaction to happen even at lower temperatures than they actually need. Too high temperatures as well as the wrong pH can destroy the active side of an enzyme that is appropriate for the break down of substrates into products. That ability can make poisonous substrates and molecules harmless, because they are separated into two products, who then can be used for different things in the body. The active side on an enzyme has a specific shape which allows the joining with just one specific molecule. Therefore a lot of different enzymes with different fields of duties are in the body. First the key and lock theory explained the joining of the active side with a fitting substrate but after more study scientists agreed that this theory isn`t that likely because enzymes are even more specific and have to make sure that the molecule that connects with their active side is definitely the one that they are able to break down.
A new theory, the induced fit model, assume that as soon as the substrate sticks to the active side of an enzyme and forms the enzyme/substrate complex, the active side changes slightly its shape and sticks even closer together with the substrate to insure that they fit together.
As more enzymes are in a solution, the higher is the rate of reaction. This is because more active sides are available and ready to join together with the other molecules in the solution. Substrates can therefore faster find a fitting active side and be broken down. With keeping the amount of enzymes increasing, it will stop having any affect of the rate of reaction, as soon as all the limited molecules of the solution found their active side.
[pic] [pic]
A pepsin molecule an egg white protein molecule
[pic]
Induced fit model – substrate broken down
Variables:
The constant factor was the amount of egg white solution (5cm3) in our six test tubes, the temperature and the pH of the enzyme solution. Therefore the six different concentrated pepsin solutions (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%) are the independent factor with effects the dependent factor, the rate of reaction or the time till the mixture gets clean.
Equipment:
|Apparatus/ Equipment |Justification |
|Egg white solution |Typical protein with peptide bonds |
|Test tubes |-easy to separate the different mixtures |
| |-good overview when a solution gets clear |
|Labels |-to identify which concentration got clear when |
|Test tube holder |-holds the test tubes |
| |-makes it easy to compare the clearness of the solutions |
|Stop clock |-to notice the time, when a solution gets clear |
|Pepsin solution (to make 0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0% |-to compare the effect of different amount of enzymes in egg white |
|concentration of enzymes) |-pepsin solution contains enzymes that are able to break down egg |
| |white’s peptide bonds |
|5cm3 pipettes, syringe |-fair test/ valid results |
| |-protein solution must be in every test tube exactly the same to |
| |make sure that the effect of enzymes wont be influent by anything |
|Cylinder |-fair test/ valid results |
Risk Assignment:
|Hazard |Risk |Control |Action |
|Glass equipment |Breakages |Use test tube racks and tongs to |Remove broken glass with dustpan |
| | |prevent glass rolling of bench |and brush in place in broken glass|
| | | |bin |
|Swallow or drink of substance |Can get poisoned |Don`t drink or swallow any |Seek medical attention |
| | |substance.
| |
| | |Warn your classmates | |
|Spillages |Slip and fall |Use test tube racks and tongs to |Inform the teacher
|
| | |transfer liquid | |
|Electricity and water |Electric shock |Do not work with water close to |Switch off the electricity. |
| | |any electricity |Seek medical attention and try to |
| | | |accord first aid if necessary |
Method:
1. We labelled 6 simple test tubes with the concentrations of pepsin, we were about to put in
(0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%)
2. With a pipette we pour 5cm3 of egg white solution in every test tube
3. From a big bowl with pepsin solution, we again used the pipette to make different concentrations of pepsin solution. Therefore we took for the first test tube no pepsin solution and 10cm3 of the egg white (0% solution), the next test tube was filled with 2cm3 of pepsin and the left 8cm3 were egg white solution. We continued this procedure for the left 4 test tubes.
4. As soon as we added the pepsin solution to the egg white, we mixed them thoroughly and started the stop watch.
5. In the test tube holder, we watched the 6 test tubes and record the time and the amount of pepsin concentration when one of them got clear.
Results:
[pic] [pic]
All at the same time
0% of pepsin: 0.2% of pepsin: 0.4% of pepsin: 0.6% of pepsin:
[pic] [pic] [pic] [pic]
0.8% of pepsin: 1.0% of pepsin:
[pic] [pic]
Result in form of tables:
|Acidified |Concentration |Time Taken (min) to turn clear |
|Pepsin |Of Pepsin | |
|Solution | | |
| | |Trial 1 |Trial 2 |Trial 3 |Trial 4 |Average |
| |0% |NC |NC |NC |NC |NC |
| |0.2% |12.4 |16.9 |15.05 |6.8 |12.7 |
| |0.4% |7.51 |17.21 |4.2 |4.25 |8.29 |
| |0.6% |3.35 |6.01 |3.5 |3.45 |4.07 |
| |0.8% |1.58 |5.53 |3.4 |3.0 |3.37 |
| |1.0% |0.5 |0.52 |0.26 |0.48 |0.44 |
[pic]
[pic]
[pic]
[pic]
[pic]
Justification:
The fact that we repeated our experiment more than once, gives us a good average to proof the hypothesis. Also the measuring with pipettes to insure that all test tubes contain the same amount of white egg solution makes it more valid.
Every trail showed the same trend, which is once more represent in the average of all 4 passes. The lowest concentration of pepsin needed the most time to come clear, whilst the highest amount speeds up the process of coming clear. Still there are differences and errors. The exceptional value in trail 2 of 17.21 min at the 40% concentration that is higher than the 20% concentration time (16.9) that was required to make the solution coming clear, may be a random error. Faults could have happened at stopping the stop watch correctly or having a slightly different of egg white solution in that test tube.
In general a systematic error could have been the different definition of a “clear solution”. Although the trials show the same tendency, the values are arranged in different heights. While one pair might have said the solution is clear when it still got a dusty colour, another pair might have wait till the solutions are completely clear and they therefore needed more time with every concentration.
To improve the experiment an official definition of “clear” must be arranged. Also mistakes in measuring must be avoid by being as exact as possible and making sure that no solution is left in the pipettes and syringes that changes the actual amount of solution we work with in the test tubes. In general the experiment could be more valid when we repeat it more than 4 times.
Conclusion:
In spite of little mistakes and differences, especially the average graph shows a negative correlation between time that is required to make the solution clear and concentration of pepsin. As higher the pepsin concentration of the solution is, the slower the solution gets clear. That supports our hypothesis because the larger amount of enzymes in our high concentrated pepsin egg white solution increases the rate of reaction by provide more active sides that can join to an enzyme/substrate complex with the egg white protein molecules and break them down, what for our eyes clears the previous milky solution.