Proceduress
1. Starch solution had been prepared from the stock solution (1.0mg/ml) into dilution of 0.01, 0.025, 0.05, 0.1, 0.3, 0.5, 0.7, and 1.0 mg/ml from the starch stock solution.
2. Iodine solution is ready with added 5g potassium iodide to 100 l water. The potassium iodide that has been dissolved is added with 1g of iodine and is allowed to dissolved.
3. The standard curve of absorbance vs concentration of a starch/ iodine is prepared.
4. The solution of substrate concentration effect and temperature effect also prepared.
Result
Substrate Concentration effect
1. Starch solution had been prepared from the stock solution (1.0mg/ml) into dilution of 0.01, 0.025, 0.05, 0.1, 0.3, 0.5, 0.7, and 1.0 mg/ml from the starch stock solution.
2. Iodine solution is ready with added 5g potassium iodide to 100 l water. The potassium iodide that has been dissolved is added with 1g of iodine and is allowed to dissolved.
3. The standard curve of absorbance vs concentration of a starch/ iodine is prepared.
4. The solution of substrate concentration effect and temperature effect also prepared.
Result
Substrate Concentration effect
Temperature effect
The equation of standard curve
Y=0.6823x-1.3111
Y= absorbance
x= the concentration of starch
The equation of standard curve
Y=0.6823x-1.3111
Y= absorbance
x= the concentration of starch
Discussion
Based on result the substrate concentration effect, the rate of reaction enzyme increased due to increasing concentration of substrate. This is because there will be more active molecule for a reaction occur. More active molecules give more chemical reactions since there will be more successful collisions at the active site of the enzyme and substrate. The rate of reaction is directly proportional to the enzyme concentration. This is because the enzyme concentration is increased which enables active sites to react with substrates, increase the rate of reaction.
In this solution of starch and amylase there are only a few amylase molecules to collide with the starch substrate. This means is less chance of collision occurring and a less probability of the enzyme being 'locked' by the substrate starch 'key'. This means there will be less effective collisions, reducing the rate of reaction.
For temperature effect, the increasing of temperature will increases the Kinetic energy of the molecules. Amylase molecules will therefore collide more, resulting the starch to be taken up by the active sites of the amylase, broken down quicker and maltose to be released. This will cause an increase in rate of reaction. However after the optimum temperature, which is above 40 c, the ionic and hydrogen bonds holding the amylase together will brake and denature, so the reaction will no longer occur. I will keep the temperature constant by keeping it at a mild temperature so the enzymes do not denature.
Conclusion
The results of the experiment showed that lowering the concentration of enzyme and adding more water, the absorbance of the solution decreases. Therefore, our experiment supports our hypothesis that higher concentration of enzyme will increase the rate of reaction. Higher concentration of enzyme - higher absorbance and color intensity
Based on result the substrate concentration effect, the rate of reaction enzyme increased due to increasing concentration of substrate. This is because there will be more active molecule for a reaction occur. More active molecules give more chemical reactions since there will be more successful collisions at the active site of the enzyme and substrate. The rate of reaction is directly proportional to the enzyme concentration. This is because the enzyme concentration is increased which enables active sites to react with substrates, increase the rate of reaction.
In this solution of starch and amylase there are only a few amylase molecules to collide with the starch substrate. This means is less chance of collision occurring and a less probability of the enzyme being 'locked' by the substrate starch 'key'. This means there will be less effective collisions, reducing the rate of reaction.
For temperature effect, the increasing of temperature will increases the Kinetic energy of the molecules. Amylase molecules will therefore collide more, resulting the starch to be taken up by the active sites of the amylase, broken down quicker and maltose to be released. This will cause an increase in rate of reaction. However after the optimum temperature, which is above 40 c, the ionic and hydrogen bonds holding the amylase together will brake and denature, so the reaction will no longer occur. I will keep the temperature constant by keeping it at a mild temperature so the enzymes do not denature.
Conclusion
The results of the experiment showed that lowering the concentration of enzyme and adding more water, the absorbance of the solution decreases. Therefore, our experiment supports our hypothesis that higher concentration of enzyme will increase the rate of reaction. Higher concentration of enzyme - higher absorbance and color intensity