Final answer:
The range of thermal tolerance is the difference between the least and the most extreme temperatures that an organism can withstand without suffering lethal consequences. High or low temperatures outside an organism's tolerance range can disrupt necessary metabolic chemical reactions by affecting the structure of proteins such as enzymes.
Step-by-step explanation:
The range of thermal tolerance is the difference between the incipient upper and lower lethal temperatures. All organisms have a certain temperature range in which they can survive; temperatures outside of this range can be lethal. This concept is essential for understanding how organisms respond to temperature changes in their environment.
For example, some plants may die after short-term exposure to temperatures as high as 38°C, whereas a temperature of 36°C might be lethal if the exposure lasts for more than an hour.
This range where organisms can survive is called their thermal tolerance range, and it varies significantly among different species.
Temperatures aside from an organism's tolerance range can disrupt the chemical reactions such as metabolism, as enzymes and other proteins can lose their structure and hence their functionality when exposed to extreme temperatures.
The concept of thermal tolerance is also reflected in the idea of a normal range, which refers to the spread of values around a biological variable's set point, like body temperature, that are considered tolerable without having health implications. However, changes to the body temperature outside of this normal range can be life-threatening.