BIO152 lab report 2 example PDF

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an example of the lab 2 report from Murdoch university. Unit: BIO152...

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BIO152 Cell Biology Lab 2 Report STUDENT NAME: Harrison Cambourakis

STUDENT NUMBER: 33421174

Results (20 marks) Effect of pH on alkaline phosphatase activity:

Describe the observed relationship between pH and enzyme activity. (2 marks) The relationship between pH and Enzyme activity on the scatter plot appear to be moderately-weak, positive and linear relationship. From the 4 th to the 5th point we can see the steep drop and this is probably due the pH reaching its optimum level and then begin to denature.

What is the “apparent optimum pH” for alkaline phosphatase from your data? (1 mark) 11.0 was the apparent optimum pH Effect of temperature on alkaline phosphatase activity:

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Describe the observed relationship between temperature and enzyme activity. (2 marks) The relationship between Temperature and Enzyme activity on the scatter plot appear to be moderate in strength, Positive and also linear. From points 1 - 4 It seems to indicate that with an increase in Temperature, we can see an Increase in Enzyme Activity due to the kinetic energy being increased with risen temperatures. With increased temperatures, the vibrational energy of the molecules also increases, and the protein molecule becomes less stable resulting in enzyme activity declining. The protein may potentially lose its structure and become denatured at high temperatures.

What is the “apparent optimum temperature” for alkaline phosphatase from your data? (1 mark) 45 degrees Celsius was the optimum apparent temperature Effect of substrate concentration on alkaline phosphatase activity:

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Vmax

Km

From your figure, determine the approximate V max and the Km constant for alkaline phosphatase. (2 marks) Vmax: 18 nmoles pNP/min/mL Km: 0.25 (mM)

Discussion (20 marks) Answer the following questions with reference to your textbook, or other appropriate resources. Effect of pH on activity of alkaline phosphatase How does your data relate to the effect of pH on enzyme activity? (2 marks) 

The data mirrors what is expected to occur from increased levels of pH. It’s evident that there is a correlating drop in Enzyme activity from the optimum pH to the point at which we can see the enzyme begin to denature (Berry, Maker, Terpolilli and Callan, (2019).

Why does the activity of the enzyme decrease on either side of the pH optimum? (4 marks)

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Each Enzyme has an optimum level of pH, which is where the pH activity Is at its apex. Altering the pH outside of this level will slow enzyme activity, therefore, Extreme levels of pH can be responsible for enzyme denaturing (Khan Academy, 2019).

Effect of temperature on alkaline phosphatase activity How does your data relate to the effect of temperature on enzyme activity? (2 marks)

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The data plotted on the graph displays some form of a cause and effect relationship. With an increase in temperature, we can see an Increase in Enzyme Activity due to the kinetic energy being increased due to the rise in temperature.

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The effect of temperature on the activity of an enzyme is the result of two opposing processes. What are they? (4 marks)

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The two opposing factors are temperature increasing to extreme heights at which kinetic energy is increased an enzyme will begin to change is shape and become less stable. As the temperature increases further, the vibrational energy of the molecules also increases, and the protein molecule becomes less stable resulting in enzyme activity to decline.

Effect of substrate concentration on alkaline phosphatase activity How does your data relate to the effect of substrate concentration on enzyme activity? Why does the curve have its particular shape? (3 marks) 

The data plotted on the graph demonstrates very similarly to that of the Michaelis-Menten curve. The Michaelis-Menten curve displays how the substrate concentration reacts with an enzyme. The initial velocity of an enzyme reaction tends toward the Vmax as the substrate concentration is attracted towards infinity. The curve is structured in this way to demonstrate the relationship between reaction velocity and substrate concentration in a timed segmented reaction graph (Berry, Maker, Terpolilli and Callan, (2019).

Are the Vmax and Km values constant for a given enzyme? Provide an explanation. (2 marks) 

Vmax is dependent on the Enzyme concentration. The Km is independent and will always stay the same. Km has the ability to change with Enzyme concentration but that isn’t related to Vmax. An Enzyme concentration must be much lower than the substrate concentration and measurement of the initial rate of the reaction must be taken into account (Ithychanda, 2014).

The alkaline phosphatase used in this assay was isolated from rat kidney. Would you expect alkaline phosphatase isolated from another source to exhibit the same apparent optimum temperature, optimum pH and Km value? Provide an explanation. (3 marks)

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No, If the alkaline phosphatase was isolated from another source this would impact the results we would expect to get. The results may be different numerically speaking, however, the concept and principles remain the same in terms of what we would expect from how our results are displayed in the scatter plot graph. pH will still have an optimum level, Temperature will still imply higher levels of kinetic energy causing denaturing and substrate concentration will still be plotted as velocity vs concentration and displaying a hyperbolic curve. The Vmax and Km constants would be different depending on the enzyme activity that is produced from the newly provided alkaline phosphatase source.

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References Hardin, J., & Bertoni, G. (2017). Becker's World of the Cell (9th ed., pp. 162-164). London: Pearson Education. Berry, C., Maker, G., Terpolilli, J., & Callan, N. (2019). BIO 152 Cell Biology Laboratory Manual (pp. 19-26). Perth: Murdoch Print shop. Enzymes review. (2019). Retrieved 29 August 2019, from https://www.khanacademy.org/science/highschool-biology/hs-energy-and-transport/hs-enzymes/a/hs-enzymes-review

Ithychanda, S. (2014). Does Km vary with Enzyme concentration. Retrieved 29 August 2019, from https://www.researchgate.net/post/Does_Km_Michaelis_constant_vary_with_enzyme_concentration

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