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Succinate is converted to fumarate by a dehydrogenase enzyme as shown - Scottish Highers Human Biology - Question 3 - 2023
Question 3
Succinate is converted to fumarate by a dehydrogenase enzyme as shown. succinate → fumarate + hydrogen the rate of this reaction can be measured using the indica... show full transcript
Worked Solution & Example Answer:Succinate is converted to fumarate by a dehydrogenase enzyme as shown - Scottish Highers Human Biology - Question 3 - 2023
Step 1
State one variable, other than those mentioned, that would need to be controlled for a valid conclusion to be drawn.
Answer
One important variable that needs to be controlled is the concentration of the DCPIP indicator solution. Ensuring that the DCPIP concentration is kept constant across all test tubes is essential for accurate comparison of results.
Step 2
Describe one possible source of error when using DCPIP in this investigation.
Answer
A possible source of error could be difficulties in accurately measuring the exact point of decolourisation of DCPIP. Factors such as lighting conditions or personal interpretation may lead to inconsistencies in determining when the DCPIP has fully decolourised.
Step 3
Suggest how the reliability of the results in this investigation could be improved.
Answer
To improve reliability, the experiment should be repeated multiple times for each concentration of succinate, and an average time to decolourise DCPIP should be calculated. This would help to minimize random errors and provide a more accurate representation of the results.
Step 4
Step 5
Describe how the results show that the inhibitor used is a competitive inhibitor of succinate dehydrogenase.
Answer
The results indicate that as the concentration of succinate increases, the time taken to decolourise DCPIP decreases, especially in the presence of the inhibitor. This suggests that the inhibitor competes with succinate for binding to the active site of the dehydrogenase enzyme, and that increasing substrate concentration can overcome this inhibition.
Step 6
Step 7
Describe the role of dehydrogenase enzymes in the citric acid cycle.
Answer
Dehydrogenase enzymes in the citric acid cycle facilitate the removal of hydrogen ions and electrons from substrates, which are then transferred to electron carriers such as NAD+ or FAD. This process is crucial for energy production.
Step 8