Biology 1113 Lab 4: Enzymes Reading: Lab manual pp. 33-50 and text book sections
ID: 276510 • Letter: B
Question
Biology 1113 Lab 4: Enzymes Reading: Lab manual pp. 33-50 and text book sections on Enzymes Purpose: Investigate the a inhibition and environmental effects on enzyme activity. ctivity of t wo enzymes: catechol oxidase and amylase. Learn about enzyme common plant enzyme that converts catechol to benzoquinone Background: Catechol oxidase is a Benzoquinone Amylase is found in many Bacteria). Amylase breaks down the polysaccharide starch into maltose, which is a disaccharide. You will is the brown color you see when you slice an apple and leave it exposed to air organisms that consume starch for food (such as animals and certain confirm th catechol oxidase by PTU. on the activity of amylase by determining how long it takes to break down sta e presence of catechol oxidase in potato extract and then test the mechanism of inhibition of Each group will also test the effects of changing environment or concentration rch. In Lab: Complete Exercise 1 to show the normal activity of catechol oxidase. Complete Exercise 2 to investigate the behavior of catechol oxidase when it is inhibited. We will discuss in class Complete one of the experiments in temperature) or enzyme concentration on amylase activity. I will assign these to each group. Groups will shar end of lab . Exercise 3 to investigate the effect of environment (pH & re their data in a common data file, which will be uploaded to Carmen at the Lab Homework: up all data sets for the amylase experiments. Upload your Word document to the Lab 4 assignment dropbox before the next lab period. Br re Ba Your write-up should include the following: Introductioh (2 pts) A question and hypothesis for each variable tested (pH, temperature, and concentration) in Methods (2 pts) Brief description of the experimental design and a prediction for each variable. Results (4 pts) Text that says what you (and the class) found, which uses proper parenthetical references to cite your figures. Graphs for each of the three amylase experiments that use all data collected (for your section) Be sure to include a figure label and caption below each figure Discussion (2pts) Interpretation of your results for each experiment. Were your hypotheses supported? Make a conclusion about environmental effects and concentration effects on enzymes based on your interpretation. .Explanation / Answer
Ph:
Question: what is the effect of ph on enzyme activity, what is the optimal ph for the given enzyme, at what ph rate of disappearance of I2KI purple color is faster.
Hypothesis: enzymes are proteins made up of aminoacids and have ionisation effects at a definite ph, based on the ph their three dimensional folding changes and accordingly their activity. Every enzyme have their unique optimal ph operation to act faster. The shape of the graph can be bell shaped
Methods:
Do the enzyme substrate reaction at various ph separately (4-9) in six test tubes. First add starch and buffer then I2KI and mix well, then add enzyme and immediately calculate the time in sec using a stop watch for color disappearance and see at what ph the decrease in color is faster and that ph is the optimum ph for the amylase
Prediction: Based on the data when amylase tested from ph 4-9 the rate of disappearance of purple color was faster (49.23sec) at ph 5 hence this enzyme having optimal ph at 5.
Results:
As shown in the figures optimum ph is found to be 5 at which enzyme reaction is faster.
Student can make graph and from the data you have collected, in the question exact data is not provided to plot a graph
Discussion:
It’s been interpreted that ph 5 is found to be optimum for amylase
Yes my hypothesis is supported
Its been concluded that ph plays a vital role in the activity of enzymes
Temperature:
Question: what is the effect of temperature on enzyme activity, what is the optimal temperature for the given enzyme, at what temperature the rate of disappearance of I2KI purple color is faster.
Hypothesis: as said earlier three dimensional folding of peptide chains changes with temperature, with increasing in temperature molecular randomness increases fluidity/plasticity of proteins should increase upto certain point, further increase in temperature should denature proteins and hence the enzyme activity should decrease. Every enzyme based on their amino acid composition have certain optimal temperature at which acts faster and performs the reaction faster. The shape of the graph can be bell shaped
Methods:
Do the enzyme substrate reaction at various temperatures separately (4, 22, 37, 80) in four test tubes. First add starch and buffer then I2KI and mix well and incubate test tubes in respective temperature water baths for some time, then add enzyme and immediately calculate the time in sec using a stop watch for color disappearance and see at what temperature the decrease in color is faster and that temperature is the optimum for the amylase
Prediction: amylase tested from 4° C to 80° C. Rate of dsapperance of color at 4° C, 22° C and 80° C is taking longer time, whereas at 37° C its faster, hence its optimal temperature is 37° C. At 4° C its freezing effect hence lesser at 80° C its melting effect in both the cases enzyme is not folded optimally to hydrolyze the starch effectively.
Results:
As shown in the bar chart optimum temperature is found to be 37° C at which enzyme reaction is faster and taken lesser time for the disappearance of color compared to other temperatures.
Student can make graph and from the data you have collected, in the question exact data is not provided to plot a graph
Discussion:
It’s been interpreted that 37° C is found to be optimum for amylase
Yes my hypothesis is supported
It’s been concluded that temperature plays a vital role in the activity of enzymes
Concentration:
Question: what is the effect of enzyme concentration on activity, what is the optimal enzyme concentration for the given enzyme, at what enzyme concentration rate of disappearance of I2KI purple color is faster.
Hypothesis: with the increase in enzyme concentration (number of molecules per ml), the enzyme activity should increase up to a certain concentrationand further increase in concentration should not show any effect or may show inhibitory effect, the shape of the graph can be bell shaped. Same is the case with the starch substrate concentration also
Methods:
Do the enzyme substrate reaction at various enzyme and substarte concentrations separately test tubes. First add buffer then various concentrations of the enzyme and substrates (seperate reactions and seperate tubes), then I2KI and mix well. In both the cases immediately after adding enzyme calculate the time. see at what enzyme or substrate concentration the decrease in color is faster and that concentration is the optimum for the amylase
Prediction: Increase in the number of molecules of the enzyme should increase the activity. In the case of substrate concentration, increase in the substrate concentration should increase the enzyme activity until substrate saturates all the enzyme active sites
Results:
As shown in the line chart at 0.5% of amylase enzyme reaction is faster and taken lesser time (<100sec) for the disappearance of color compared to other concentrations.
Student can make graph and from the data you have collected, in the question exact data is not provided to plot a graph
Discussion:
It’s been interpreted that 0.5% of amylase concentration is found to be optimum
Yes my hypothesis is supported
It’s been concluded that enzyme concentration plays a vital role in the activity of enzymes
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