How does the high heat capacity of water help support life?

Question

How does the high heat capacity of water help support life?

Answer 1

Hi Christina I.,

Life requires homeostasis, growth, and reproduction (details may vary, depending on organism type!). As far as I know, the thermal homeostasis that water promotes is what this question is targeting. Exterior and interior sources of heat, and exterior sinks for heat, may all present threats to this. Water, with its high heat capacity, buffers against thermal changes from these, which means that constant active control of temperature is not required, except at a total-organism level. For mammals, evaporation of sweat is also a vital part of shedding excess heat.

I might point out that if you are dehydrated, under viral attack, or using certain drugs of abuse (e.g. 3,4-methylenedioxypyrovalerone, or other "bath salts"), all the bets are off for passive thermal control, and you may die of hyperthermia (causing multi-system organ failure) unless intensively treated.

Hope this gives you some ideas to pursue further,

-- Cheers, -- Mr. d.

Answer 2

Water has high heat capacity due to hydrogen bonding between molecules. Energy must be absorbed to break these bonds and released when they break. Heat capacity defines the amount of energy needed to raise the temperature of a substance by one degree.

A high heat capacity means that more energy is required to increase the temperature of water by 1 degree so it requires more time to heat or cool. This resistance to temperature fluctuation is important in regulating body temperatures in organisms that have a high composition of water. Water can be used in the body to transport heat evenly in warm-blooded animals. The same property of resistance to large temperature fluctuations also makes water a good habitat for many organisms.