To Investigate The Effect Of PH On The Rate Of Enzyme Activity Flashcards
Name the enzyme you used.
Catalase
What reaction does catalase catalyse?
Converts hydrogen peroxide into water and oxygen
Investigating temperature. Explain how you ensured the temperature was kept at or below 10 degrees Celsius.
Thermostatically controlled water bath
Investigating temperature. Suggest why a buffer solution might be used.
To keep pH constant
Investigating pH. Suggest how in the absence of a suitable buffer, the pH solution could be altered.
Addition of an acid e.g. lemon juice
Explain how you measured enzyme activity.
Measuring the height of the foam in the graduated cylinder after a set period of time (after two minutes)
Explain why there is a dramatic fall off in enzyme activity at temperatures above 40 degrees Celsius.
The enzyme is denatured.
The enzyme has lost its 3-D shape and the shape of its active site has changed
Why has enzyme activity dropped to zero at 50 degrees Celsius?
Enzymes are denatured
Give a factor other than pH which affects enzyme activity.
Temperature
What is the source of catalase.
Celery
What is the substrate of catalase?
Hydrogen peroxide
Explain why changing the pH would have an effect on enzyme activity.
Active site is changed as the enzyme is denatured
When investigating pH, what variable other than temperature did you keep constant.
Volume of hydrogen peroxide
At what pH would you expect optimal activity for catalase?
pH 9
Explain how you varied the pH during the course of the investigation.
(2)
Varied pH
pH of 4, 7, 10 and 13
