Factors that effect the rate of reaction will be:1. Temperature
2. Concentration
3. Surface Area
4. Catalyst.
Factors that effects enzymes reaction is:
- Temperature
- Concentration of substrate
- Amount of substrate
- Amount of enzymes
- PH of enzymes
Factors that effect enzyme reaction are:
Temperature:
When two chemicals react, their particles have to collide one another with sufficient energy in order for the reaction to take place but they will only react if they have enough energy that means the temperature have to be high in order for a reaction to happen quickly. So by increasing the Temperature the particles will move faster and the rate of reaction will increase, If the Temperature is high they don’t need of sufficient energy because the Temperature is more likely to be greater than the amount of Activation energy needed for the particles to collide faster. So therefore if the Temperature is less the particles will collide more slowly and the time taken for a reaction to occur will decrease.
This image taken from tiscali.co.uk.
This image shows me that as the temperature increases the substrate molecule is broken down by the Catalyse will increases because the particles gains more energy for them to react but as the decrease in Temperature the particles will collide even more slowly.
Concentration of substrate:
If the concentration of the substrate is low then the particles will float about so there will be less collision in the particles and they wouldn’t take so long to react that means there are less collision taking place which means the rate of reaction decreases however if there are more concentration of the substrate then there will be more collision taking place that means that the rate of reaction increases.
The 1st container tells me that the particles are floating but because there are more concentration they are free enough to collide so there are more collision taking place.
The 2nd image tells me that the particles are floating about but because there is not much concentration there is not a high chance for them to collide.
PH of enzymes:
All enzymes have a PH whether it is alkali or acid. The enzymes work best is the PH is high for fixed enzymes but if it is low then the enzymes will work slowly. So if the PH is optimum then all the enzymes work best and the rate of reaction will increase.
Amount of enzymes:
If I add a little amount of enzymes then the rate of reaction might increases because higher the enzyme molecules then it will breakdown lots of substrates.
Amount of substrate:
The higher the amount of substrate the higher the rate of reaction will be because the particles will be free so they collide each other more often so the rate of reaction will increases.
Catalyst:
Catalyst speeds up chemical reaction without being used up. The Catalyse and it’s job is to breakdown the Hydrogen Peroxide (H2O2) to form Water (H2O) and Oxygen (O2) in this experiment. Enzymes work by decreasing the Activation energy needed for a reaction to occur, so the smaller the Activation energy is the less job for the catalyse. Hydrogen Peroxide is toxic to cells so the catalyse protect the cells from getting toxic thus it breakdown the H2O2 into Water and Oxygen.
There are three different ways how catalysts work:
- Kinetic theory
- Adsorption
- Intermediate Compound
Variables:
Apparatus:
Diagram:
Method:
- First of all I will collect all the apparatus out and ready
- I will then check if they are completely clean in order to accurate results.
- I should check whether the bung has a delivery tube attached to it and then end up at the gas syringe.
- Then set the apparatus as shown above
- I will cut the potato into 5 equal sides needed (2 cm)
- Then I will prepare a range of the hydrogen peroxide concentration by diluting with water like the table shown below.
- Then I will place a flask in the water bath and then I will add my concentration of hydrogen peroxide solution one by one after finishing the earlier concentrated.
- Then I will add one of the potato on to the substrate solution and immediately I will place the bung on the top of the flask and then I will start the stop watch as soon as I put the bung on top of the flask.
- I will measure the oxygen produced in the gas syringe every 1 minutes.
- Then I will put the solution in the different beaker. Then I will clean the flask in the tap water to get ready for the next step.
- Then I will repeat this two times or more so that I could check my accuracy and it is easy for me to plot the graph by taking the average from the results.
- I will do this to other molar of the hydrogen peroxide as well and then I will repeat it again to check my accuracy.
Risk Assessment:
- Hydrogen peroxide can damage my clothes So I have to rinse any spills with water immediately.
- I should handle the Hydrogen peroxide with care because it is corrosive and an irritant.
- Keep hydrogen peroxide out of my eyes.
- Wear safety goggles to prevent my eyes from getting any harmful substances especially from hydrogen peroxide because it is corrosive and irritant.
- I should always report any accidents of spills to my teacher so that she might help me with it and will tell me what to do.
- When I’ am collecting the apparatus I should be really careful it might fall over and will break because most of the equipment are made up of glass.
- Wear safety gloves from getting any hydrogen peroxide spills because the highly concentrated ones are so dangerous it might just burn my hand.
- I should be really be careful when cutting the potato because I might end up cutting my own fingers.
- I should wear aprons from getting any spills of hydrogen peroxide, universal indicator or any other substance that are involved in this experiment.
- If I am wearing a tie then I should tuck that inside my shirt or t-shirt or I should make sure that I don’t wear a tie at all.
- I should wear a sleeveless t- shirt or a shirt inside the apron from getting any harmful substance in my skin.
- I should not play with the distilled water or run in the labs or even stay there doing nothing that means I should be mature.
- I shouldn’t use more than 2.0 molar of hydrogen peroxide because it is dangerous and might burn our skin but anyway my teacher is not going to give it.
- I should check if everything is attached together well because sometimes it might just fall over and then it cause to break.
Precision, accuracy, and reliability:
∙ I will make sure to keep the temperature and the PH constant so that I could get accurate results. I will do this by doing the experiment in a room temperature.
∙ I should repeat the experiment twice in order to get accurate results and I will work out the average so that it will be easy for me to plot a graph.
∙ I should keep the size of the potato same in order to get reliable results, I will do this by making sure that the size of the potato is same by measuring it twice.
∙ I have to use the same size equipment by using the same apparatus again through out the experiment and I should check if they are not broken before doing the experiment to get accurate results.
∙ I should follow the method through out the experiment in order to get reliable results.
Improving planning:
∙ I have to try to improve my reaction time because I should be able to everything by myself (e.g. when I add the potato in I should be able to place the bung as quickly as possible and then I should start the stop watch as quickly as I can because I have to do this to get accurate and reliable results because when I did my chemistry experiment I couldn’t manage everything by myself and because of that I didn’t get a reliable and accurate results.
∙ I have to keep the syringe in my eye level because it will be easy for me to read it and I should be able to able to check the time every 5 minutes without doing something else that means I should concentrate in my experiment in order to get accurate results.
∙ When I’ am doing my experiment I should know what exactly I’ am doing so that I don’t have to waste my time and others by asking them how to do it so I should follow my method through out my experiment.
∙ I will use conical flask instead of using beaker to do the experiment because conical flask has a small open on the top so it is easy to place the bung on to the conical flask but in beaker I can’t put the bung which means the air releases outside so I won’t get accurate and reliable results so it is way better to use conical flask.
Sources that I used:
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