Hydrophilic & hydrophobic interactions underlie several properties of water that are biologically important. 1. Temperature-Stabilizing Effects:
Note: The temperature of a substance is a measure of how fast its molecules are moving; the higher the temperature of a substance, the faster its molecules are moving.
a.) heating water - It takes considerable heat to raise the temperature of water because the hydrogen bonds between the water molecules restrict the movement of the molecules; in order for the temperature of water to rise, a number of H bonds must be broken - this takes a lot of energy. This resistance to temperature change helps living cells to maintain a relatively constant temperature; this is important because biochemical reactions take place within a narrow temperature range (this has to do with the action of enzymes). This resistance to temperature change also helps organisms that live in aquatic or marine environments.
2. Water As a Solvent - the polarity of water is also responsible for water's capacity as a solvent (something that dissolves something else); water is an excellent solvent for ions & other polar molecules (solutes) in cells.
Note: The temperature of a substance is a measure of how fast its molecules are moving; the higher the temperature of a substance, the faster its molecules are moving.
a.) heating water - It takes considerable heat to raise the temperature of water because the hydrogen bonds between the water molecules restrict the movement of the molecules; in order for the temperature of water to rise, a number of H bonds must be broken - this takes a lot of energy. This resistance to temperature change helps living cells to maintain a relatively constant temperature; this is important because biochemical reactions take place within a narrow temperature range (this has to do with the action of enzymes). This resistance to temperature change also helps organisms that live in aquatic or marine environments.
2. Water As a Solvent - the polarity of water is also responsible for water's capacity as a solvent (something that dissolves something else); water is an excellent solvent for ions & other polar molecules (solutes) in cells.