Hey! I was wondering if anybody could hepl me with this practicle that we got for our assessment; to determine the optimum temperature at which the enzyme renin acts on milk. We have to use junket as it contains renin. Does anyone have any idea as to how I could measure the rate of reaction? Any help is much appreciated!!!
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yet another question about enzymes (1 Viewer)
- Thread starter Helstar87
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lukebennett
Happy Member
hey there! this is what we did for one of our practicals. its quite straight forward but can be tricky to get your head around at first. The rate would be best measured by just measuring the time it takes for the solution to become solid. you compare the rate of the reaction of solutions of renin and milk one where the renin is in a boiled waterbath, one where the renin is cooled or even just defrosted in a waterbath and one where the renin is at room temperature and at a range of other temperatures. keep the variables controlled in terms of amount of renin (should be the same in each test tube), the dependant variable is the rate of reaction of time to react, the independant variable is the temperature of the reninHelstar87 said:
hope that helps
lukebennett
Happy Member
ill look in my prac book for you if i can find itHelstar87 said:
lukebennett
Happy Member
it goes something like this:
4 test tubes- 3 with 4mL of renin. 1 with milk at 5'C, 1 with milk at 37, 1 with milk at 37'C but renin boiled. 1 as a control with just milk at 37'C.
observe the reactions and the time needed for the reactions to take place (solutions will go solid and jelly like). put obs in a table. the fastest reaction indicates the optimal temperature range tested in the prac (note another temperature may be more effective)
4 test tubes- 3 with 4mL of renin. 1 with milk at 5'C, 1 with milk at 37, 1 with milk at 37'C but renin boiled. 1 as a control with just milk at 37'C.
observe the reactions and the time needed for the reactions to take place (solutions will go solid and jelly like). put obs in a table. the fastest reaction indicates the optimal temperature range tested in the prac (note another temperature may be more effective)
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Wow!!! Thanx so much your a legend! Just one other question though, you have to mix the junket tablets (containing rennin) with water right? So do you use boiling water to make up the junket for each temperature??? Thanx again!
lukebennett
Happy Member
sorry i cant remember about that part but it wouldnt be in boiling water cause that would denature the rennin which would ruin the experiment. i think you can just put the tablet in the milk but it is probably dissolved in water. ill see what i can findHelstar87 said:
lukebennett
Happy Member
yes it is dissolved in water (distilled water but not boiled). just ensure you make equal concentrations of and volume for each test tube for a valid experiment
Here is an alternate method only involving temperature as a variable.
Basically you have to use water baths at different temps. with ice and hot plates to produce 8 water baths at temperatures 10, 20, 30...up to 80 degrees. Constantly monitor with thermometer to ensure it is stable. Now each water bath should have 2 test tubes, one with 10 mL milk (control) and one with 10 mL of milk and one junket tablet (which contains renin, or you can use some other form of renin). From there you just measure the time for the milk to curd. Some will not curd as the renin either denatures (too hot) or becomes dormant (too cold). The temperature where it curds quickest is the optimum temperature.
edit: just in case i didnt make it obvious, a water bath is simply a tray with water in it.
Basically you have to use water baths at different temps. with ice and hot plates to produce 8 water baths at temperatures 10, 20, 30...up to 80 degrees. Constantly monitor with thermometer to ensure it is stable. Now each water bath should have 2 test tubes, one with 10 mL milk (control) and one with 10 mL of milk and one junket tablet (which contains renin, or you can use some other form of renin). From there you just measure the time for the milk to curd. Some will not curd as the renin either denatures (too hot) or becomes dormant (too cold). The temperature where it curds quickest is the optimum temperature.
edit: just in case i didnt make it obvious, a water bath is simply a tray with water in it.
lukebennett
Happy Member
no probs. if you have any problems pmHelstar87 said: