Subject: What might affect metabolism and hence catalase production in vertebrates?

Dear Matt.  Thanks for your original reply, but i am now having problems 
answering some of the questions I have set myself to answer. I
have answered bits of all of the following myself from
the masses of complex information I have found on the
Internet, but I am not sure I have got it 100%
correct: (particularly qu.1,4 and 5)

1) What is Catalase?
2) Where is it produced and found in vertebrates?
3) Where is it found in the liver?
4) What is its purpose genrally and specifically in
relation to (Hydrogen or other) Peroxide?
5) Since catalase is involved in metabolism, What
differences are there between different vertebrates
(e.g. between say birds and mammals and fish) that
might affect metabolism and therefore catalase
production in that type of vertebrate?

Re: What might affect metabolism and hence catalase production in vertebrates?