Enzymes only work on one reaction due to their shape.
The temperature differs how quick the particles move. The higher the temperature, the faster the particle moves. They therefore collide more frequently and with more frequently and with more energy. This then makes it easier for them to react together. Usually, rises of 10◦c will double the rate of a chemical reaction.
Graph A
The rate of reaction doubles with every 10◦C rise in temperature. This is because the molecules which are reaction move faster and have energy at higher temperatures.
Graph B
Between 0-40◦C, the rate, the rate of reaction rises in just the same way as in graph A for just the same reason.
At 40◦c, the enzyme begins to be damaged, so the reaction slows down. By 60◦C, the enzyme is completely destroyed. 40◦C is the optimum temperature; the temperature at which the rate of reaction is greatest.
Most of the chemical reactions are happening inside a living organism controlled by an enzyme. Enzymes are very sensitive to high temperatures to high temperatures. On the temperature gets about 40◦C they begin to be damaged. When this happens to an enzyme, it cannot catalyze its reactions as well, hence the reaction slows down. At higher temperatures, the reaction will stop completely because the enzymes.
Prediction
I predict that the higher the concentration of the enzyme the faster the reaction.
In general, concentrated solutions react more quickly than dilute ones. In a concentrated solution react more quickly than dilute concentration. In a concentrated solution there are more collisions per second between the reacting particles, so the reaction proceeds more quickly. As you increase the concentration, it will rise until a point where it stays constant because the enzymes have run out of active sites which slows down the rate of reaction.
To keep in the reaction rates increasing, it can have more enzymes. This then suggests that f you double the concentration, you will double the enzymes therefore you will double the reaction rate.
The lock and key theory applies to the process of how starch is broken down in to maltose. Only one enzyme is designed for one particular substance, therefore it cannot react to another substance. The reason it cannot do this is, because the shape of it is different to the substance.
The downside of this process is that only a limited amount can fit at the active sites which can makes the process itself slow.
Apparatus
Spotting palette
1% starch
Concentrated solution 0.25%-1.25%
Pipettes
Iodine
Test tube
Test tube rack
Timer
Method
- Put 2 drops of iodine in to each dimple on the spotting tray. Keep pipettes separated to prevent cross-contamination and making sure you use the same pipette for the same job.
- Collect water from the water bath and place the enzymes on it for a couple of minutes to get the enzymes working.
- In the meantime, mix starch and amylase of 0.25%.
- Put 2 drops of solution into the dimples which contain iodine. Start the timer. Every 20 seconds put the concentrated solution in to the dimple containing iodine.
- Watch for the change of colour; form brown to black. Stop the timer once the colour has changed.
- Record the time taken for the starch to convert in to sugar. Make sure it is concentrated in to seconds.
- Repeat the experiment for 0.5%, 0.75%, 1% and 1.25&.
Fair test
- Keep the same amount of solution.
- Put in drops of the same amount-2 drops.
- Keep using the same pipettes for the same thing. Measure the time of the product that the reaction took.
- Measure the amount of drops you use.
- Change the solution concentration.
- Change the pipette for different things. For example, do not use the same pipette for the iodine and the solution.
Safety
- Make sure you wear goggles at all times during the experiments.
- The iodine is an irritant. Watch out if it goes on your clothes as the stain is impossible to remove.
- Handle with care when taking the water from the water bath, watch out in case you burn your hands.
Results
Conclusion
Thee results show me that the increase in concentration provides an increase in rate per gram. The reason for this to happen is that as you increase the concentration within the solution, more energy is provided to the reacting particles. Hence, there are more collisions per seconds which allows the whole reaction to proceed quicker.
My prediction was correct. The higher the concentration of the enzyme, the faster the reaction. Also my other prediction was also fairly correct. If you double the concentration, you double the speed. The only reaction this was fairly correct because the actual experiment might have had mistakes which might have affected the results. If there were not as many mistakes, I think that my theory would have practically worked.
There were a few anomalies in our graphs. This might refer to our results. Our results were the quickest in reacting. This might have made a huge difference. This affects our results and makes it more in accurate and unrealistic.
Evaluation
I can see there are inaccuracy’s in my results. This can be seen on the experiment itself, the results we got and the graph. The problem that caused this in the experiment was mainly human errors. The simplest error caused a huge difference. We varied our mistakes; some of them were the amount of drops put into the spotting tray. Others maybe cross-contamination, luckily this happened on rare occasions.
Other faults were using different iodine solution. They all varied strengths and came out in different colours. If we had enough supply of the same solution, there would definitely be no problem with the iodine.
To prevent cross- contamination, we could have used labels on the pipettes and other instruments. We could also have special pipettes to allow certain amount of drops.
The other problem was time, if we had enough time, we would be able to repeat the procedures enough to get a decent average.
For a further investigation and to support my conclusion, I will have a second method. To produce this evidence, I will have to produce an investigation to produce the similar results. The things that we need to keep in mind are that we had problems with the colour. To resolve this, I will change the enzyme. The substrate I will use is a chemical metabolic waste known as hydrogen peroxide. It is produced by every cell. It is catalyse that reacts with the toxin to make water and oxygen. The chemical formula is:
2h2o2→H2o+o2
This will prove my conclusion because as the enzyme reacts with the hydrogen peroxide, two substances are created. They are water and oxygen. The oxygen will go through the pipe in to the water and up the measuring cylinder. This will show is how much oxygen is collected and measure it with the cylinder of how much oxygen is collected up.
