How much quicker would carbohydrase digest starch at 35c than 25c?

I've got this question in my textbook -- it has a graph showing the effect of carbohydrase on a starch solution at a temperature of 25c and optimum pH. After 16 minutes, most of the starch has been digested and the line on the graph reaches its lowest point.
It wants me to redraw the graph demonstrating what would happen if the test was repeated at a temp of 35c.

As it is a 10% increase in temperature, would the carboydrase digest the starch 10% quicker (i.e., it would be mostly digested after 14.4 minutes rather than 16)? Or, as 35c is very close to an enzyme's optimum temperature, would it digest the starch much, much quicker than 10%?

If anyone could shed any light on this, I'd really appreciate it. Everyone knows enzymes work quicker at higher temperatures, but I can't find anywhere where it actually tells you how much quicker!!

Thank you very much! :smile:

Reply 1

username890104

Original post by LegateTatiana

Where do you get the 10% from? It is a temperature 10 degrees higher, but this doesn't represent 10%.

I don't expect you'll need to work out the increase in the rate, but merely acknowledge that there would be an increase in the rate due to it being closer to the optimum temperature and so sketch the graph accordingly.

Reply 2

roflcakes1

For most reactions, an increase of 10 degrees doubles the rate of reaction.

Reply 3

LegateTatiana

Original post by roflcakes1

For most reactions, an increase of 10 degrees doubles the rate of reaction.

Thank you, very, very, very helpful!

Original post by Tullia

Where do you get the 10% from? It is a temperature 10 degrees higher, but this doesn't represent 10%.

You're so right -- I don't know where I got that 10%. Right now I have a cold and an ear infection, so I'll put it down to that! :smile:

Reply 4

username890104

Original post by LegateTatiana

You're so right -- I don't know where I got that 10%. Right now I have a cold and an ear infection, so I'll put it down to that! :smile:

Not to worry, we all make mistakes. It's learning from them that counts. I would have mentioned the general rule that the rate of reaction doubles with a 10 degrees increase in temperature when temperatures are around room temperature, but I got the feeling you were doing a sketch more than an accurate graphical representation.

As long as you have the correct starting and finishing point, and a correct gradient then that should be suffice.

What exam board are you with?

Reply 5

POWApril

i think this is the question in my textbook! i'm having trouble with the part about pH, and what the effects of pH2 would be on carbohydrase. it would denature the enzyme but i don't know how quickly (and i've got to do a graph demonstrating the effects!)

does anyone know how quickly carbohydrase would denature at pH2? would it be able to digest any of the starch first?

thank you!! I have to hand this in tomorow and this is the last bit i need to do!

Reply 6

username890104

Original post by POWApril

Carbohydrase would be denatured at pH 2. It wouldn't digest any of the starch.

Reply 7

loukas2993

At 35c the starch molecules would convert a large proportion of the thermal energy into kinetic energy and would be moving at a much greater rate! This means that the random chance of one molecule of starch performing a "successful collision" with the carbohydrate enzyme's active site increases a great deal - this factor coupled with the approach to the enzyme's optimum operating temperature suggests that the carbohydrate would be performing at Vmax (maximum velocity)!