Question: Some bacteria are metabolically active in hot springs because

1. they are able to maintain a lower internal temperature.
2. high temperatures make catalysis unnecessary.
3. their enzymes have high optimal temperature.
4. their enzymes are completely insensitive to temperature.

Bacteria are prokaryotic microscopic organisms that can be found everywhere on the earth. It can survive inside animals and plants as well as the pleasant and harsh environmental conditions.

The internal temperature of bacteria is the same as that of the environment. This means they do not have a lower internal temperature when compared to their surroundings.

Therefore, the given option is false.

At high temperatures, the enzymes of the bacteria inactivated.This is because enzymes are protein in nature, and they get denatured at a higher temperature that might lead to the cell's death.

Thus, the higher temperature does not favor catalysis as enzymes get denatured.

Therefore, the given option is false.

Enzymes work best at optimal temperatures. Optimal temperature refers to a temperature range where an enzyme achieves its maximum reaction rate.

There is an optimal temperature for all enzymes. The optimum temperature for most is 35°C to 45°C. However, certain enzymes such as Taq polymerase of Archaebacteria can survive at 100°C.

Bacteria that live in hot springs are metabolically active because the enzymes of such bacteria have a high optimal temperature. The optimal temperature of enzymes of thermophilic bacteria is about 75°C.

Therefore, the given option is true.

Enzymes being proteins, are susceptible to heat. This is because high temperature disrupts the bonding among polypeptides responsible for the stable conformation of proteins.

Like all enzymes, bacterial enzymes are also sensitive to heat, but they have high optimal temperatures.

Therefore, the given option is false.