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Question:

Rennin is an enzyme originated from the forth stomach of ruminant animals like cows and goats. Its substrate is the milk protein, Casein. It can also be produced by some microorganisms by genetic engineering techniques. In milk, it denaturates the casein and clot it in a process called milk coagulation.

For more information about food enzymes link to
 http://blossoms.mit.edu/videos/lessons/antioxidant_enzymes_three_or_four_veggies_day_keeps_aging_away

Researchers at the Lab conducted an experiment to test the activity of the Rennin enzyme. They filled 4 test tubes with 10 ml. of row milk each. They marked the tubes with numbers 1, 2, 3, 4 respectively. They add to tubes 1 and 2 each 1.5 ml of a 1% rennin solution and to tubes 3 and 4 they add nothing.
They placed tubes 1 and 3 in a water bath at 10° C temperature, and tubes 2 and 4 in a water bath at 37° C temperature. They checked whether milk coagulation has occurred in the tubes after 20 minutes.

Based on what you've learned about enzymes and the attached movie, which of the following sentences describes the expected experiment results?

 

3 People tried to answer this question

Milk coagulation after 20 minutes will occur only in the two tubes with the enzyme .

Milk coagulation after 20 minutes will occur in all the tubes.

Milk coagulation after 20 minutes will occur only in one of the tubes in the 37°C bath.

Milk coagulation after 20 minutes will occur only in the two tubes in the 37°C bath .

Very good! You have understand the experiment correctly. 

Read again the experiment details. Try to make a sckech. It will help you organize the information. 

Try to recall temperature affcet on enzyme activity. 

Please recheck the researchers' work. 



Comments:
1.  magen boaz (12.06.2017 pm 07.49.49)
cheese proceess

I like your job very much ,

In the attached film I could see and understand the proccess of milk coagulation , the impotance of the Rennin anzim in the process  of milk coagulation .

I also like your story about first cheese creation .

I suggest to improve the film by addition knowledge about the relation between the temperature and the milk coagulation process success.

Best regards,

Boaz Magen

2.  magen boaz (01.07.2017 am 10.41.11)
Peer Assessment

The question is related to the procees of milk coagulation which prepared by adding Renin solution to the milk and the temperature affect on enzyme activity.

I like your movie (as I write in the previous comment ) , but I could not find a relevant  knowledge about the temperature affect on the enzyme activity in attached movie.

The question included  most of the criteria for a multi-choice question: background, video, feedback for every disturbance, and the question ends with a question mark. However I found some spelling mistakes in the feedback distractors-for example : You write sckech instead of sketch , or affcet  intead of affect.

Hints given for wrong answers : 
Hints given after the student answers incorrectly encourages the student to continue trying to solve the problem again, which leads to the solution.

In the form of this behavior we support increased internal motivation, which support SDT theory.



History of edits
Edited BY: Yardena Levy Edit Date: 2017-06-20 21:44:12
Edited BY: Yardena Levy Edit Date: 2017-06-20 21:38:54
Edited BY: Yardena Levy Edit Date: 2017-06-20 21:37:54
Edited BY: Yardena Levy Edit Date: 2017-06-20 21:34:40
Edited BY: Yardena Levy Edit Date: 2017-05-26 15:29:32
Edited BY: Yardena Levy Edit Date: 2017-05-26 15:27:52
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