There are many factors affecting enzyme action for example temperature effects them, if the Increasing the heat gives molecules more kinetic energy so they vibrate this can then make the bonds brake and change the shape of the active site. This then means that the substrate no longer fits so there can be no end product. The PH can also affect the enzyme action as enzymes can only work under the conditions that they are suited to.
Another factor is the concentration substrates because if there are more substrate there is more chance that the substrate and enzyme will find each other to make an enzyme-substrate complex. Inhibition can also affect enzymes, there are two types of inhibitors they are the competitive and non-competitive. A competitive inhibitor has a shape similar to the substrate. This means that they compete for the active site and block it off so that no substrate can fit in to it. A non-competitive inhibitor has its own site which changes the shape of the active site ones the inhibitor changes the active site no substrate can fit in to make an end product.
Some plants make their own organic molecules however other organisms need to eat food. Extracellular digestion is where a plan secretes enzymes into its surrounding area to digest it. Were as in animals enzymes are secreted inside their body to digest most of it its absorbed through the epithelium of the small intestine into the blood and lymphatic system by a variety of mechanisms.
Enzymes are also involved in the regulation of glucose levels and other reactions like this. This is where a substrate will meet with an enzyme and the end product would be for example