So the concentration of hydrogen ions, the PH, can also affect the activity of enzymes. For instance, the human body actually spends a lot of its energy in making sure that the PH of the blood as well as other systems, other fluids within our body, remains at a specific level. And at times it can basically change the PH of certain fluid areas within our body to basically activate or deactivate certain enzymes. So for instance, the human body spends a good amount of energy to keep the fluid environment at a specific PH in order to ensure that different enzymes basically function effectively and properly. Now, the enzymes in our blood, for example, require a PH of about 7.4. And if the PH fluctuates even a small amount the enzymes will basically lose their functionality and this can be a very deadly scenario.