When looking at enzymes and the effect of temperature, what does a straightening line on the graph mean?

  • 0 votes

Is it that the enzyme has been denatured because of the temperature being too high, or is it because all the substrate has been used up? 

Posted Sun 1st April, 2012 @ 10:49 by Megan Wood

3 Answers

  • 3 votes

Im assuming you're talking about a flat horizontal line.

Well the straight line indicates that something else has become the limiting factor which means something else now affects the enzymes rate of reaction. This scenario you have presented cannot be temperature or pH because for temperature, after 35-40 dergrees celcius, the line curves down to zero. For pH it gets a bit more complicated because the line curves at both extremeties but im not going into that detail.

I would probably assume that it is a graph for eznyme concentration or substrate concentration because if you have equal amounts of substrate and enzymes then you are going to have the highest rate of reaction (everything else controlled!) and even if you increase the substrate concentration then you are going to end up with the straight horizontal line that you were asking about. In this scenario, all the enzymes active sites have been taken up therefore the rate of reaction cannot increase further without changing a controlled variable like temperature. This straight line shows that all the enzymes active sites have been occupied therefore it can only hydrolyse at a certain rate and cannot increase and it is for that reason why the line becomes straight and horizontal.

if i have not answered your question please comment again so i can  try and find out what you need help in .

hope i helped though


Answered Sun 1st April, 2012 @ 12:48 by Braniac
  • 0 votes

Yes! Thankyou! I got so confused with all the different graphs and curves :S but yeah I understand now, thanks :) x

Answered Mon 2nd April, 2012 @ 09:57 by Megan Wood
  • 0 votes

no probleamo!!!!


Answered Tue 3rd April, 2012 @ 20:31 by Braniac