Investigating the Effects of Temperature on Decay of Milk and Lipase in Milk

The video tutorial explores an experiment to study the effects of temperature on milk decay, using a pH sensor to monitor changes. Due to the slow decay process, an alternative experiment with lipase is proposed. This involves measuring the time for a color change in milk mixed with lipase and cresol red, indicating pH changes. The results are plotted to determine the optimum temperature for lipase activity, found to be around 38°C.

What is the primary reason for monitoring pH changes in the milk decay experiment?

• To track the production of lactic acid by bacteria

• To determine the volume of milk

• To measure the temperature of the milk

• To observe the color change in milk

Why is the alternative experiment using lipase considered over the milk decay experiment?

• Lipase is easier to obtain

• The milk decay experiment is too fast

• The milk decay experiment requires long monitoring times

• Lipase does not require temperature control

What role does cresol red play in the lipase experiment?

• It increases the temperature

• It serves as a pH indicator

• It acts as a preservative

• It neutralizes the solution

At what temperature is the boiling tube with lipase solution initially placed in the water bath?

• 15 degrees Celsius

• 20 degrees Celsius

• 30 degrees Celsius

• 25 degrees Celsius

What is the significance of the color change from purple to yellow in the lipase experiment?

• It signifies the pH has dropped below 7.2

• It shows the pH has increased

• It indicates the solution is too hot

• It means the experiment is complete

What does the minimum point on the curve of best fit represent in the lipase experiment results?

• The highest temperature tested

• The maximum rate of lipid digestion

• The lowest pH level reached

• The average time for color change

Based on the experiment, what is the approximate optimum temperature for lipase activity?

• 35 degrees Celsius

• 38 degrees Celsius

• 40 degrees Celsius

• 42 degrees Celsius