Question

An enzyme is active in the stomach of an animal but quickly loses its activity when it leaves the stomach. This example illustrates that enzymes are?

1) specific to the organs in which they are produced
2) inactivated by movement
3) sensitive to changes in pH
4) inactivated by inhibitors in the small intestine
5) consumed by the quantities of substrate in the small intestine

Answer 1

Enzymes are sensitive to changes in pH, which affects their activity. They work best under specific environmental conditions, and a change in pH can denature them, reducing or inhibiting their catalytic function.

Step-by-step explanation:

An enzyme being active in the stomach but losing activity when it leaves the stomach illustrates that enzymes are sensitive to changes in pH. The stomach's acidic environment provides an optimal pH for certain digestive enzymes like pepsin, which works best at a pH around 1.5. In contrast, other enzymes such as trypsin work optimally in the less acidic environment of the small intestine with an optimal pH around 8. Enzymes' shapes, and subsequently their activities, are highly influenced by the pH of their environment. A change in pH can denature an enzyme, changing the shape of its active site and preventing it from performing its catalytic function.

For example, enzymes like salivary amylase have specific optimal conditions they require to function properly. This sensitivity to environmental conditions, including pH, ensures that enzymes exhibit their maximum activity only within a narrow pH range, which further supports the idea that enzymes are designed to operate most efficiently in the environmental conditions where the organisms that produce them live.