To evaluate the activity of salivary amylase enzyme, students collected samples (I, II, III andIV) of amylase-starch mixture at different times and added a drop of iodine reagent to each sample.The given table shows the resulting colours and the amount of starch remaining in each sample.Based on the resulting colours of the iodine test, the sample which shows the highest level of amylase activity is
Correct answer: C. III
- A. I
- B. II
- C. III
- D. IV
Explanation
Salivary amylase breaks down starch. The iodine test turns dark blue-black, when starch is present and becomes brown/yellow when little or no starch remains.From table:Sample I: Dark blue-black → all starch present → very low amylase activitySample II: Blue → most starch present → low activitySample III: Golden brown → no starch left → highest amylase activitySample IV: Light brown → some starch left → moderate activitySo,Sample III shows the result expected when starch is completely digested, hence it represents the highest level of amylase activity. Other samples showing any color change suggest that some starch still remains, indicating lower amylase activity. While sample III shows no starch sample left.
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About Factors Affecting Enzyme Action
Enzyme activity changes with temperature, pH, substrate concentration and enzyme concentration because these factors affect molecular collisions and the active site. Questions also examine optimum conditions, denaturation and inhibition, while distinguishing a fall in activity caused by unsuitable conditions from permanent enzyme damage.
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