CBSE Class 12 Biology Experiment No
CSBE – Class 12 – Biology – Experiment 12
Experiment No. 12
Aim- To study the effects of temperature on the enzymatic activity of salivary amylase on substrates starch.
Materials required- Test tubes, beakers, pipettes, funnels, thermometer, cotton, starch, iodine, potassium iodide, sodium chloride, thermocol box, buffer solution of pH 6.8 & match box.
Principle- Salivary amylase is an amylolytic enzyme found in saliva released from salivary glands. All the enzymes show optimum enzymatic activity around 37° C which is our body temperature. Any deviation from optimum temperature can influence configuration of enzymes which involves folding of polypeptide for acquiring & maintaining its catalytic & allosteric sites.
Decline in temperature modifies the catalytic site & the enzymatic activity is significantly lowered & enzyme is deactivated. However, deactivated enzyme can resume its optimum activity whenever optimum temperature of 37° C is provided again. Increase in temperature on the other hand hampers the catalytic site & enzymatic activity is lost forever & enzyme is denatured. Procedure: In each experimental tubes, add 1ml of diluted enzyme. Immediately with the help of a dropper, take a drop each from these tubes & add to the tubes having iodine. Note the time reading as 0 minute reading. After an interval of 2 to 4 min, again take a drop from each tube & add to the iodine tubes & note the change in the color of iodine. Keep on repeating it after an interval of every 2 to 4 min till the color of iodine does not change any further.
Observation table:
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Page 1
CSBE – Class 12 – Biology – Experiment 12
Temperature
Time taken to reach the achromic point
Result: It takes less time to reach achromic point at 37° C as the enzyme is ,maximum active at this temperature while at higher & lower temperatures more time is taken to reach the achromic point.
Explanation: All enzymes are chemically protein in nature. At higher temperatures, proteins
Experiment No. 12
Aim- To study the effects of temperature on the enzymatic activity of salivary amylase on substrates starch.
Materials required- Test tubes, beakers, pipettes, funnels, thermometer, cotton, starch, iodine, potassium iodide, sodium chloride, thermocol box, buffer solution of pH 6.8 & match box.
Principle- Salivary amylase is an amylolytic enzyme found in saliva released from salivary glands. All the enzymes show optimum enzymatic activity around 37° C which is our body temperature. Any deviation from optimum temperature can influence configuration of enzymes which involves folding of polypeptide for acquiring & maintaining its catalytic & allosteric sites.
Decline in temperature modifies the catalytic site & the enzymatic activity is significantly lowered & enzyme is deactivated. However, deactivated enzyme can resume its optimum activity whenever optimum temperature of 37° C is provided again. Increase in temperature on the other hand hampers the catalytic site & enzymatic activity is lost forever & enzyme is denatured. Procedure: In each experimental tubes, add 1ml of diluted enzyme. Immediately with the help of a dropper, take a drop each from these tubes & add to the tubes having iodine. Note the time reading as 0 minute reading. After an interval of 2 to 4 min, again take a drop from each tube & add to the iodine tubes & note the change in the color of iodine. Keep on repeating it after an interval of every 2 to 4 min till the color of iodine does not change any further.
Observation table:
©IGYANZONE PVT LTD
Page 1
CSBE – Class 12 – Biology – Experiment 12
Temperature
Time taken to reach the achromic point
Result: It takes less time to reach achromic point at 37° C as the enzyme is ,maximum active at this temperature while at higher & lower temperatures more time is taken to reach the achromic point.
Explanation: All enzymes are chemically protein in nature. At higher temperatures, proteins