What is the effect of enzyme concentration on enzyme activity? Explain how enzyme activity changes as enzyme concentration decreases, and discuss why this occurs (on a molecular level).

Since this is not my area of expertise, I searched Google under the key words "enzyme concentration activity" to get these possible sources:

http://www.chemsoc.org/networks/learnnet/cfb/enzymes.htm
http://www.worthington-biochem.com/introbiochem/enzymeConc.html
http://student.ccbcmd.edu/~gkaiser/biotutorials/proteins/enzyme.html
http://en.wikipedia.org/wiki/Enzyme_assay
http://en.wikipedia.org/wiki/Enzyme

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.

The effect of enzyme concentration on enzyme activity is primarily influenced by the number of enzyme molecules available to catalyze a reaction. As the concentration of enzymes increases, the rate of the enzymatic reaction generally increases.

To explain how enzyme activity changes as the enzyme concentration decreases, we need to understand the concept of enzyme-substrate complex formation. Enzymes function by binding with specific substrate molecules to form an enzyme-substrate complex. This complex then undergoes a series of reactions to convert the substrate into the desired product.

At a higher concentration of enzymes, there are more enzyme molecules available to bind with the substrate, resulting in a higher likelihood of enzyme-substrate complex formation. As a consequence, the reaction rate increases.

Conversely, when the enzyme concentration decreases, there are fewer enzymes available to bind with the substrate. This leads to a lower probability of enzyme-substrate complex formation and, consequently, a decrease in the rate of the enzymatic reaction.

On a molecular level, the decrease in enzyme activity can be attributed to the limitations in enzyme-substrate collisions. When the enzyme concentration is low, the chances of a substrate molecule colliding with an enzyme molecule and forming an enzyme-substrate complex decrease. As a result, the frequency of successful reactions decreases, resulting in a slower reaction rate.

Additionally, it is important to note that there is an optimal enzyme concentration for achieving maximum activity. Beyond a certain point, increasing the enzyme concentration does not significantly increase the reaction rate, as the available substrate molecules become the limiting factor. This point is often referred to as enzyme saturation.

In summary, as enzyme concentration decreases, enzyme activity decreases due to a lower frequency of enzyme-substrate complex formation and limited collisions between the enzyme and substrate molecules. Understanding the relationship between enzyme concentration and enzyme activity provides insights into enzyme kinetics and the factors that influence enzymatic reactions.