Answer;
The first graph represents such an enzyme.
Explanation;
This is because the enzyme demonstrates greatest activity at approximately 37 °C but then the activity starts to decrease due to the denaturing of the enzyme.
As the temperature increases, so does the rate of reaction. But very high temperatures denature enzymes. The graph shows the typical change in an enzyme's activity with increasing temperature. The enzyme activity gradually increases with temperature up to around 37 ºC, or body temperature. Then the activity decreases above 37 ºC, because above this temperature the enzymes will denatured.
