Final answer:
A calorie is the amount of energy necessary to raise the temperature of 1 gram of water by 1°C. It reflects the specific heat capacity of water, which is high, making water an effective temperature regulator.
Step-by-step explanation:
The amount of energy necessary to raise the temperature of one gram of water by one degree Celsius is the definition of a calorie. A calorie (cal) is the unit of energy which is particularly used to express the amount of heat needed to increase the temperature of a specific mass of water. Specifically, raising the temperature of 1 gram of water by 1°C is equivalent to 1 calorie. This property is also referred to as the specific heat of water. It is important to note that the term "calorie" discussed in dietary contexts is actually a kilocalorie (Kcal), which is 1000 times larger than the calorie used in the physical sciences.
When considering the heat capacity of water, it's understood that water has a high specific heat capacity, which means it requires a significant amount of heat to change its temperature. This makes water an excellent regulator of temperature, both in environmental contexts and within living organisms, where it acts to transport heat and maintain a stable internal temperature. For example, the heat capacity of water aids in how warm blooded animals regulate their body temperatures.