Re: what makes the rate of reaction increase of catalase on h2o2?

Catalase and Complicated Wording

Roopal - 

	Ok, based on what you wrote, I can unravel a few questions:
1)  You want to know what makes the rate of decomposition action of catalase 
increase when applied to H2O2 (hydrogen peroxide).

	Several things can cause an observed increase in the reaction of a 
catalyst (here it's the enzyme catalase). 
a) The easiest one is the increase the amount of the catalyst.  Though in 
this case each individual catalase molecule is not working any faster, just 
more catalyst is working, so the reaction proceeds faster.

b)You can actually increase the speed at which the catalase molecules do 
their job by changing the temperature... usually by heating it up.  
Sometimes there are other chemicals that can act as helpers, or pH (acid or 
base) conditions that speed up a reaction.

c)You can also increase the rate of reaction by increasing the avalible 
reactant (in this case H2O2 - the stuff being changed by the catalase).  
Because if there is more catalyst than stuff it can change, some of the 
catalase will sit around doing nothing, until it can get some to work on.  
If you increase the amount of H2O2, more catalse can work, so the rate 
increases.

2)  Now it seems that your source of catalase is the potato (which is a good 
choice since it is significantly less stinky (niffy?) than liver - another 
good source).  And you are wondering why adding more potato makes the 
reaction proceed faster.
	Well if you go back and look at the ways you can make a reaction go 
faster - adding more potato means you are adding more catalase.  Therefore 
the reaction will go faster due to reason a) (above).
	Now here's a good thing for you and your teacher to test... try putting 
the same amount of potato (same mass) into two different test tubes - with 
the H2O2.  However, in one, keep the potato in one big chunk, and in the 
other, crush the potato.  Which do you think will go faster?  Why?  (Think 
about which one can expose more catalase to the H2O2!)

Hope this helps!
Greta Hardin

P.S.  A quick note about using the word THEORY...  More potato making the 
reaction happen faster is a FACT, a simple phenomenon that you can easily 
measure.  The potato chunk vs. crushed potato test I proposed should cause 
you form a HYPOTHESIS... _IF_ I do _THIS_ to the potato, _THEN_ something 
should happen.  After you have fiddled around with potato catalse and H2O2 
for awhile, you can then come up with a THEORY about potato catalase and 
H2O2 in general.  
	It is important to have these things straight as you proceed further 
into the scientific world!