Question

Indicate whether each of the following enzymes would be functional: a. pepsin, a digestive enzyme, at pH 2 b. an enzyme at \(37^{\circ} \mathrm{C}\), if the enzyme is from a type of thermophilic bacteria that has an optimum temperature of \(100^{\circ} \mathrm{C}\)

Short answer

a. Yes, pepsin would be functional at pH 2.b. No, the enzyme would not be functional at 37°C.

Step-by-step solution

Analyze Pepsin at pH 2

Pepsin is a digestive enzyme that functions optimally in the acidic environment of the stomach. The stomach typically has a very low pH, around 1.5 to 2. Therefore, pepsin would be functional at pH 2 as it is within its optimal pH range.

Analyze the Enzyme from Thermophilic Bacteria at 37°C

Thermophilic bacteria are known to thrive at high temperatures. The enzyme mentioned comes from thermophilic bacteria and has an optimum temperature of 100°C. Since the enzyme's optimal activity occurs at 100°C, it is unlikely to be functional at 37°C, which is significantly lower than its optimal temperature.

Key concepts

optimal pH

Enzymes are proteins that speed up chemical reactions in the body. Each enzyme has an optimal pH at which it works best. The optimal pH is the specific pH level where the enzyme's activity is at its peak. For pepsin, an enzyme that aids in digesting proteins in the stomach, the optimal pH is very acidic, around pH 1.5 to 2. This makes sense because the stomach environment is naturally acidic, which helps pepsin break down proteins efficiently.

If the pH level is too high or too low, the enzyme can become denatured, meaning it loses its shape and, therefore, its ability to function. Different enzymes work best at different pH levels depending on where they operate in the body. For instance, while pepsin works best in acidic conditions, other enzymes, like trypsin found in the small intestine, work best in more neutral conditions.

thermophilic bacteria

Thermophilic bacteria are a type of microorganism that thrives at high temperatures. Unlike most bacteria that prefer moderate temperatures, thermophilic bacteria can survive and grow in extremely hot environments, such as hot springs, geothermal vents, and compost heaps. These bacteria have adapted to high temperatures by evolving enzymes and proteins that remain stable and functional when it is very hot.

The enzymes from thermophilic bacteria are particularly interesting because they don't denature (lose their shape and function) at high temperatures like enzymes from other organisms might. This makes them very useful in industrial processes that require high temperatures. For example, certain biotechnological processes use enzymes from thermophilic bacteria to catalyze reactions that need to occur at elevated temperatures without the enzyme losing its activity.

optimal temperature

Every enzyme has an optimal temperature at which it works most efficiently. The optimal temperature is the specific temperature that allows the enzyme to catalyze reactions at its highest rate. Most human enzymes have an optimal temperature close to our body temperature, around 37°C (98.6°F).

Thermophilic bacteria, however, have enzymes with much higher optimal temperatures. For example, an enzyme from thermophilic bacteria might have an optimal temperature of 100°C. If this enzyme is placed in an environment with a much lower temperature, like 37°C, it would not function well because the enzyme's structure and the dynamics of the enzyme-substrate interactions are not favorable at that lower temperature.

In the original exercise, the enzyme with an optimal temperature of 100°C would likely be inactive at 37°C. This massive difference in optimal temperatures showcases how specialized enzymes are for their specific environments and how crucial optimal conditions are for enzyme activity.