ATAR Notes: Forum

VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Biology => Topic started by: kerry.j on March 05, 2013, 07:51:16 pm

Title: Enzyme SAC question?
Post by: kerry.j on March 05, 2013, 07:51:16 pm: I just did the enzyme practical today, it was with liver and hydrogen peroxide, we had four test tubes each with hydrogen peroxide and the following added to it:

- A: sand
- B: sand and a cube of fresh liver
- C: sand and ground fresh liver
- D: sand and a cube of boiled liver

I know that in test tube D nothing is meant to happen because the enzymes are denatured, but my group and the other groups doing the experiment observed bubbling and oxygen produced in the test tube. Is it possibly because the boiling process didn't completely denature the enzymes? My tutor said that if I wanted to say that I needed more evidence...
Thanks in advance for any help!
Title: Re: Enzyme SAC question?
Post by: academicbulimia on March 05, 2013, 08:05:20 pm: Quote from: kerry.j on March 05, 2013, 07:51:16 pm

I know that in test tube D nothing is meant to happen because the enzymes are denatured, but my group and the other groups doing the experiment observed bubbling and oxygen produced in the test tube. Is it possibly because the boiling process didn't completely denature the enzymes? My tutor said that if I wanted to say that I needed more evidence...
Thanks in advance for any help!

Yeah that is a possibility, also maybe certain enzymes in the liver can withstand certain temperatures while other denature quicker-they denature at different temperatures.
You could try and look up some examples of these enzymes and their different response to temperature as evidence..
Title: Re: Enzyme SAC question?
Post by: kerry.j on March 05, 2013, 09:04:09 pm: Quote from: academicbulimia on March 05, 2013, 08:05:20 pm
Yeah that is a possibility, also maybe certain enzymes in the liver can withstand certain temperatures while other denature quicker-they denature at different temperatures.
You could try and look up some examples of these enzymes and their different response to temperature as evidence..

I've tried what you said and to search for other enzymes, but it seems like catalase is the enzyme for the breaking down of hydrogen peroxide which is what is being tested, so the other enzymes in the liver wouldn't be relevant. And as for catalase it most likely operates optimally at body temperature, so boiling should be more than enough to denature it.
Title: Re: Enzyme SAC question?
Post by: Yacoubb on March 05, 2013, 09:09:45 pm: You could simply mention this as a systematic error; the protein was not completely denatured, as demonstrated by the bubbling of the test tube sample and the production of Oxygen. You would probably only need to give evidence that although the enzyme had exceeded its optimum temperature, enzyme activity had not completely diminished, but was just very low, and so as a result, you got the production of Oxygen and bubbling of the sample in test tube D.
Title: Re: Enzyme SAC question?
Post by: kerry.j on March 05, 2013, 09:51:27 pm: I see, thanks for that. (: I also wanted to make sure that that was the only explanation for the results.