Which statement is true regarding enzymes?

Enzymes are biological catalysts that significantly increase the rate of chemical reactions without being consumed in the process. They do this under mild conditions, such as physiological temperatures and pH levels, which are suitable for biological functions in living organisms. By facilitating reactions efficiently, enzymes ensure that metabolic processes can occur swiftly and effectively without requiring extreme conditions.

For example, enzymes such as amylase and lipase catalyze reactions in the human body at optimal temperatures around 37 degrees Celsius and near-neutral pH levels, enabling digestion to occur efficiently. This ability to function under mild conditions is crucial for sustaining life, as extreme conditions could be damaging to cellular structures and physiological processes.

The other statements do not accurately describe enzyme activity: enzymes do not require extreme conditions, they are not consumed in the reactions they catalyze, and they can function across a wide range of pH levels, not limited to only acidic environments.