And at this point we say the protein is denatured and it no longer functions because the tertiary structure is basically the structure that determines the functionality of that protein. And because enzymes are proteins, we see that eventually the rate of activity of enzymes reaches a certain point at which it has a maximum activity rate. And increasing the temperature past this point will denature or break down the tertiary structure of that enzyme and lower that enzyme's activity sharply. Now, one example is the human body. The human body has a core temperature of about 37 degrees Celsius. And this is because most of the proteins, the majority of the proteins are enzymes in the human body, function optimally at this temperature of 37 degrees Celsius.