Photo AI
A space probe recently returned to Earth from a distant planet, with samples containing bacteria X - HSC - SSCE Biology - Question 29 - 2004 - Paper 1
Question 29
A space probe recently returned to Earth from a distant planet, with samples containing bacteria X. Biologists are interested in comparing the activity of an enzyme... show full transcript
Worked Solution & Example Answer:A space probe recently returned to Earth from a distant planet, with samples containing bacteria X - HSC - SSCE Biology - Question 29 - 2004 - Paper 1
Step 1
State a hypothesis to be tested
Answer
My hypothesis is that the enzyme extracted from bacteria X will show higher activity at the higher temperature range (50–80°C) compared to the enzyme from bacteria E, which grows at a lower temperature range (37–55°C). This is based on the understanding that enzymes typically exhibit peak activity within the temperature ranges their respective organisms thrive in.
Step 2
Plan an investigation under ONE of these conditions
Answer
-
Select Temperature and pH: Choose a temperature condition, such as 60°C, within the range of Bacteria X and a matching pH level of around 6.5 (which is within the acceptable range for both bacteria).
-
Equipment List: Gather required materials such as test tubes, a water bath set to 60°C, pH meter, substrate solution, and a gas collection apparatus to measure the volume of gas produced.
-
Independent Variable: The type of bacteria (Bacteria X and Bacteria E).
-
Dependent Variable: The volume of gas produced as a measure of enzyme activity.
-
Controlled Variables: Ensure consistent temperature (60°C), pH (6.5), substrate concentration, and equal durations of reaction for both bacteria.
-
Repetition: Conduct the experiment at least three times for each bacterium to ensure reliable results.
-
Risk Assessment: Identify potential hazards such as handling hot equipment and working with biological materials, and implement measures to mitigate risks, such as using gloves and goggles.