Please read and help me ASAP...

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indigo-ink
indigo-ink's picture
Please read and help me ASAP...

Hi
I am writing up a practical work at the moment, and it's on the effect of enzyme concentration on the rate.

My line graph shows that the rate at which 1% concentration of protease catalysed 1% concentration of milk protein is less steep than that of the catalysis of 0.75% milk protein.

Can I explain that by saying there could be more substrates in the 1% milk soln than there are enzymes in the 1% protease soln? Or is it just an anomalous result?

From what I know in chemistry surely 1% reacting with 1% is a 1:1 reaction, but I got confused and started thinking:

maybe there could be more moles in the 1%enzyme soln than the 1% substrate soln. I am really desperate please help....

Richard Taylor
Richard Taylor's picture
Think from the point of view

Think from the point of view of the person trying to assess your report.

Show that you understand the theory. Write what you expected would happen, that as you increased the substrate concentration, you expected the reaction rate to increase. (Perhaps you can be more quantative)

Once you've done that discuss why you didn't get the result that you expected.

From what you've described so far you've only got two substrate concentration values that you've investigated: 0.75% and 1%, you need more over a sutibly wide range to determine the effect of substrate contentration on rate.

Does substrate concentration affect your technique for measuring rate?

A good source for more information on this area is:
http://en.wikipedia.org/wiki/Rate_of_enzyme_mediated_reactions

indigo-ink
indigo-ink's picture
Thank you for your advice on

Thank you for your advice on writing it up I was stuck on that too; however, my main worry is explaining these particular "anomalous" results.

I've got 5 sets of results, 2 of which I have mentioned before.
values for 1% and 0.1% seem to be the only ones slightly out of the pattern, and I did not know how to explain those results.
How do I determine if they are anomalies and if not, can I say it's because the same concentration of 2 different solutions do not always react 1:1? (I guess this is more to do with chemistry.)

And what do you mean exactly by "Does substrate concentration affect your technique for measuring rate?"

Richard Taylor
Richard Taylor's picture
indigo-ink wrote:...How do I

indigo-ink wrote:

...How do I determine if they are anomalies

Ideally you would go back and try the experiment again, you could repeat each measurement for each substrate concentration multiple times and get an idea of the error involved, the range of the results, their distribution etc.
In practice you probably aren't able to do that here, but you can write that as a possible next step for determining if your results are "unexpected".

indigo-ink wrote:

Can I say it's because the same concentration of 2 different solutions do not always react 1:1?

I don't think this line of thinking is relevant here. In "Chemistry" terms an enzyme is a catalyst.

indigo-ink wrote:

And what do you mean exactly by "Does substrate concentration affect your technique for measuring rate?"

If you were to repeat your results and determine that you reproducibly saw that in your experimental set up the rate of your reaction wasn't following what you expected you would need to look for other explainations of your results - that is what I am suggesting here.

Lastly you might find you get better and faster help here and elsewhere if you don't cross-post to multiple forums, don't use huge fonts, but do use more informative thread titles.

indigo-ink
indigo-ink's picture
Thank you. So I'll just treat

Thank you. So I'll just treat it like an anomalous result but say it needs to be repeated to make sure it's not part of what's supposed to happen.
I'm new to sites like this one and I did not know where to post what, I had no idea that 'medium' font was that big either. sorry about that. i'll keep that in mind.
This has really helped me though, thanks a lot.