How does temperature affect enzyme activity in a chemical reaction?

Question

The rate of a chemical reaction always decreases with increasing temperature and always increases with decreasing temperature.
The rate of a chemical reaction always decreases with increasing temperature and always increases with decreasing temperature.

The rate of a chemical reaction initially increases with increasing temperature and then decreases, eventually stopping, when the temperature gets too high.
The rate of a chemical reaction initially increases with increasing temperature and then decreases, eventually stopping, when the temperature gets too high.

The rate of a chemical reaction initially increases with decreasing temperature and then decreases, eventually stopping, when the temperature gets too low.
The rate of a chemical reaction initially increases with decreasing temperature and then decreases, eventually stopping, when the temperature gets too low.

The rate of a chemical reaction initially increases with increasing temperature and continues to increase indefinitely as temperature continues to increase.

Answer 1

The most accurate statement regarding the effect of temperature on enzyme activity in a chemical reaction is:

The rate of a chemical reaction initially increases with increasing temperature and then decreases, eventually stopping, when the temperature gets too high.

Explanation:

1. Increasing Temperature: As temperature increases, the kinetic energy of molecules increases, which generally leads to more frequent and effective collisions between enzyme and substrate molecules. This results in an increased rate of reaction.

2. Optimal Temperature: Each enzyme has an optimal temperature range in which it functions most effectively. For many enzymes, this is typically around 37°C for human enzymes.

3. Denaturation: However, if the temperature continues to increase beyond this optimal level, enzymes may begin to denature. Denaturation involves changes in the enzyme's structure, which can lead to a loss of function. As the structure of the enzyme is altered, the active site may no longer properly bind substrates, resulting in a decrease in the rate of reaction.

4. Stopping Activity: Eventually, at very high temperatures, enzyme activity can stop altogether due to complete denaturation.

Therefore, temperature has a significant effect on enzyme activity, with an initial increase in reaction rate followed by a decline as the temperature becomes too high.