Again, Knowledge

What knowledge have you connected with past knowledge during Biochemistry?

Using the text, Campbell & Farrell, Biochemistry and classroom PowerPoint presentations, I wish to confer my new and improved understanding of enzymes and their specific characteristics. First and most importantly, is the fact that their are two main groups of enzymes, differentiated by the form of activation. The naming of both groups follows a the same pattern. That is the descriptive of what it pertains or acts on and the suffix "-ase". Lipase is active on lipids and is a typical naming example.

The first and probably the more simple of the two is the non-allosteric enzyme. This form of enzyme is either activated or inhibited by a non-competitive inhibitor through the active site or main physical shape specific connection to other molecules; most often taking the shape of proteins. This category of enzymes follow a very specific and well defined mathematical model called the Michaelis Menton model, the equations and specifics of which are readily available on line. This model when graphed produces a hyperbolic curve, making it easy to pick out when all that you have to go by is a graph on a exam or lab practical.

The second and probably more complex of the two is the allosteric enzyme. The allosteric enzyme is so named, for its additional "allosteric" activation site. Instead of following the Michaelis Menton model for behavior, the allosteric enzyme group instead follows the "sequential model". Hemoglobin is a terrific and familiar example of this model, exhibiting this type of binding type of binding. In the case of Oxygen binding on the individual heme subunits, the binding affinity increases with 1 to 4 Oxygen atoms bound. This transforms the enzyme from a type T to a Type T-R, to a Type R as the atomic unit substrates bind to the quaternary subunits.

Finally and possibly more important is the action of the enzymes no matter the type. Enzymes are catalysts first and foremost. All catalysts, however, are not created equal. The enzymatic catalytic reactions are several orders of magnitude better than the best non-enzymatic catalyst reaction. This means that the reaction in living organisms can be fast enough and efficient enough to maintain the various complex systems of life. In short, we owe much of who and what we are to enzymes.

MCB