An enzyme is a biological catalyst which speeds up biochemical reactions, such as digestion and respiration, but they remained unchanged at the end of the process (Walpole, Merson-Davies, and Dann 53).
What is the effect of the substrate concentration on enzyme activity?
As the concentration of the substrate increases, the rate of reaction also increases until it reaches its maximum point where all enzyme molecules are already active due to the solution becomes saturated with the hydrogen peroxide. Therefore, when the rate of reaction is finally at its maximum point, adding more substrate will not make any difference to the rate of reaction.
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The experiment was done on the same lab and same room temperature
3 The time of the reading. The time of when solution of water and hydrogen peroxide (H2O2) is injected to the boiling tube should be the same because if it is different, the volume of oxygen released into the long graduated tube will be different. Set the time 30s for the reading every time the oxygen is released from the syringe into the long graduated cylinder.
10g of dried yeast suspension in 500mL water
10% and 20% of hydrogen peroxide solution
5 boiling tube
1 1mL plastic syringe
1 10mL plastic syringe
2 clamps and stands
1 delivery tube
1 inverted burette
1 800mL beaker filled with water
Collect and prepare all the materials.
Carefully connect them as shown in the diagram. (Picture 1.2)
Add 5mL of the yeast suspension into the boiling tubes.
Take out the 1mL plastic syringe and fill it with various concentrations of hydrogen peroxide (H2O2) starting from 1mL to 10mLand then also fulfill the rest of the capacity of the syringe with water.
Put the syringe on into the needle and inject the solution quickly, but very carefully into the boiling tube. (Picture 1.3)
As the solution is injected into the boiling tube, time it with a timer for 30s to see the volume of oxygen released into the long graduated tube. (Picture 1.4)
Repeat the method above with different concentrations of the substrate, but keep the same amount of the yeast suspension, which is 5mL.
Determine and write down the rate of reaction in each of the concentrations of the H2O2by reading the burette.
To do this experiment, one must make sure that he or she is under the guidance of someone who has the experience of working in a lab (e.g. Science teacher).
Wear the laboratory coat as it provides protection for the body.
Wear gloves at any time during the experiment as the hydrogen peroxide (H2O2) solution is dangerous to the skin.
In figure 2, the mean is used to be a summary statistic that shows where the center of the data sets using five trials; rate of reaction (mL/min) based on each % concentration of H202. Standard deviation is the measure of central tendency and gives a better picture of the data. The smaller the value of standard deviation, the greater the data concentrated around the mean.
Rate of Reaction (mL/min) by % Concentration of H202
Trial 1 5 10 15 20
1 2.2 7.6 28.4 57.8 66.6
2 2.2 7.6 25 49.4 65.4
3 1.8 8.4 23.4 52.4 68.6
4 2.2 9.4 25 55.6 71
5 2.8 8 30.8 52.8 70.6
Mean 2.24 8.2 26.52 53.6 68.44
Standard deviation 0.35777 0.74833 3.00865 3.21559 2.44295
X ̅= (∑▒X)/n
Where Σ = Sum of
X = Individual score
N = Number of scores
S= √((∑▒〖(X-M)〗^2 )/(n-1))
The graph above shows the % concentration of H2O2 on the x-axis and the mean of the rate of reaction...