Question

Identify the two important classes of catalysts. Analyze the chemical reactions that take place when a biological catalyst combines with a reactant (substrate) to form an unstable intermediate.

For the two important classes of catalyst I have homogeneous and heterogeneous. Is this correct? I still need help wit hthe second part of the question though.

Answer 1

Yes, homogeneous and heterogeneous are the two types of catalyst unless you want to include autocatalysts. Here is a site that looks good to me.
http://www.chemguide.co.uk/physical/catalysis/introduction.html