Final answer:
Enzyme activity with respect to pH is typically represented by a bell-shaped curve due to the optimal pH at which enzymes function most efficiently and the decreased activity on either side of this optimum.
Step-by-step explanation:
Graphs that depict enzyme activity with respect to pH typically show a bell-shaped curve. This is because enzymes have an optimal pH at which they function most efficiently, and their activity decreases on either side of this optimum. Therefore, the correct answer to the question about enzymes sensitive to changes in pH and the type of curve they would show on a graph is c. Bell-shaped curves.
Looking at enzyme kinetics, each enzyme's activity is greatly influenced by the pH of its environment. When the conditions are optimal, usually near the middle of the pH range for that enzyme, activity is at its peak, forming the top of the bell-shaped curve. When the pH shifts away from the optimal range, enzyme activity decreases, creating the declining slopes of the bell on either side of the peak.