Enzymes are proteins that act as catalysts in biochemical reactions. They speed up the rate of a reaction, but can also be affected by various factors. In order for an enzyme to work properly, it must have the right environment and certain conditions need to be met. This includes temperature, pH level, and the presence of competitive or non-competitive inhibitors.

Competitive inhibitors are molecules that bind with enzymes at their active sites and prevent substrates from binding and fitting into them. These molecules compete with substrates for enzyme attachment sites which slow down the reaction rate because they take up space in the active site leaving no room for substrate molecules to bind and form an enzyme-substrate complex (ES). Competitive inhibitions may also lead to a decrease in substrate affinity meaning that there is less likelihood of ES formation due to lower forces acting between them. As a result, this leads to slower rates of product formation as well as decreased maximum reaction velocity (Vmax). To counteract this effect, high concentrations of substrate must be present so that there is more chance for product formation despite competitive inhibition present.