Enzyme Substrate
Substrate in Active Site
Product released
Enzyme
Research also shows:
- Enzymes are proteins
- Each enzyme contains one particular reaction
- They can be used over and over again.
- They are affected by temperature and PH.
- There are two main types of enzymes.
- One being intra-cellular enzyme that controls reactions taking place inside the cell.
- The other being extra-cellular enzymes that control reactions taking place outside of the cell.
Preliminary Experiment
The purpose of preliminary work is to do an experiment and modify it to suit what I am investigating.
Apparatus
- Pipette
- Iodine
- Starch
- Spotting tile
- Stop watch
- Test tube
- Amylase
Method
Firstly I washed my hands and set out the experiment correctly so the experiment goes well. I put a drop of iodine, which is approximately the same amount in to the 12 wells in the spotting tile. Then I got the stop watch ready and put a mixture of 1cm³ of 1 % amylase solution to, 5cm³ of 1% starch in a test tube. Then added the solution into each well according to the time span. Then I recorded my results.
Results
Add one drop of Add one drop of Add one drop of
Starch alone to Starch 1% amylase Starch 1% amylase
This well. To this well. To this well after 30 seconds
0 min 30 sec 1 min
1 min 30 sec 2 min 2 min 30 sec 3 min
3 min 30 sec 4 min 4 min 30 sec 5 min
Starch turns iodine Blue-Black colour. When starch is broken down it will not turn iodine into a blue-black colour. We knew that the starch had all gone because the solution turned colourless. The starch formed glucose when it was broken down.
Improvements To Suit Investigation
To suit the needs of my investigation I will have to change some procedures of my preliminary experiment.
Firstly since we are trying to investigate How The Concentration Of Amylase Affects The Rate Of Reaction Between Starch And Amylase. We will need to change the concentration of amylase and starch. The range of concentration will be from 100%-10%.
Method Modified
Equipment:
- 2 Test Tubes- to put the amylase and starch in.
- Iodine- To add with the starch.
- Amylase- To put into the test tube.
- Starch (1%) - To put into the test tube.
- Measuring Cylinder- To measure the correct quantities of liquids.
- Stop Watch- To time the experiment
- Beaker- To put the test tube inside it which acts like a water bath.
- Thermometers- To measures the temperature of the water bath.
- Pipette- To measure correct quantities of the liquids used.
Using the above equipment and using the procedure below the experiment will be done.
For example we will start of with 10% concentration of amylase.
Test Tube 1 Test Tube 2
1 ml Of Amylase
9 ml Of Water 5 ml Of Starch
(With Iodine)
Now 20% concentration of amylase.
Test Tube 1 Test Tube 2
2ml Of Amylase
8ml of Water 5 ml Of Starch
(With Iodine)
We have to do the same procedure for every concentration.
After this we will have to do the following:
- Prepare water bath up to 37 degrees
- Measure the appropriate amount of amylase for the concentration in a test tube.
- Measure 5ml of Starch in another test tube
- Add Two drops of Iodine into the Starch
- Place both test tubes in water bath
- Add amylase to starch
- Start timing straight away and stop the stop watch when solution when it turns colourless.
- Record the result
- Repeat the whole experiment for the different concentration of Amylase. Ranging form 100%-10% going up in 5%
Results
This table shows us the results that I had recorded during the experiment. This results table proves that the higher the concentration of the amylase the faster starch is broken down. We know this because 100% concentration of amylase takes the quickest time (7.275) and 10% takes the longest amount of time (750.405).
By looking at this graph it tells us more clearly that the higher the concentration of the amylase the faster starch is broken down. This graph also shows how dramatically the change is between the concentrations and also it also shows close it is between different concentrations.
Reliability
While doing the experiment I tried to make the experiment as fair as possible. I did this by:
- Measuring each solution as carefully as I can.
- Keeping the water bath at a constant temperature (37)
- Adding the same amount of iodine into each the starch.
- Starting the time as soon as putting the starch into the amylase.
- Stopping the time when I saw the solution go colourless.
- Washing the two test tubes after each experiment starts.
I reckon that all my results are fairly reliable as I have done the best to make it a fair test. However if I had more time I would have done the whole experiment more than twice so I could get an accurate result. Also I would have done more concentrations such as:
If I had done this then I would be able give more reliable results and also show more solid evidence to prove my predictions right. Also if I had a real water bath keeping the temperature constant then I would have got perfect results as the water bath we had was made to act like one.
Safety Procedures
While doing the experiment I took many safety procedures such as:
- Being careful using the iodine as it can be very harmful to the skin.
- Holding the water bath with a firm insulator so I don’t burn my self.
- Also have to wear goggles because iodine is a very harmful.
These safety procedures have to taken into precaution as it can save you from certain disasters.
Analysis
In conclusion my experiment did prove that my prediction was correct. The higher the concentration of the Amylase the quicker the breakdown of Starch. This is because there are more amylase particles in a higher concentration of amylase then there is in a less concentrated amount of amylase. As there is more concentrated amylase particles to collide with the starch particles, the starch particles would be reacted quicker. So basically the more collisions there are the faster the rate of reaction. Both the results table and graph shows this to be correct. The preliminary experiment helped a lot towards my final experiment as it set me up to do the experiment. The preliminary experiment also gave me a vague idea of how I can be able to the final experiment and it also gave me a lot of insight on it.
There were many difficulties I had to face while doing the experiment these were:
- Keeping the water bath at a constant temperature (37)
- Measuring each solution properly
- Trying to tell whether the full solution has turned colourless
Difficulties like these had to be faced to do the experiment.
Evaluation
The experiment on whole was quite a success. The procedure I went through was fairly accurate was I got reliable results from using the method. The results were fairly reliable as I cannot say they were perfect results because never had enough time to give the actual proper perfect results.
If I had more time then I would have done the experiment more times to see if the results were accurate enough. Also I would also of had varied the range between the concentration of the amylase. If I had an actual water bath then the results would have come out really accurate as we used a substitute in place of a water bath.
So in conclusion the higher the concentration of the Amylase the quicker the breakdown of Starch.