Water and Life Chap3 Flashcards
Polar covalent bonds in water molecules
Result in hydrogen bonding.
Hydrogen bonds
Hydrogen bonds form between multiple molecules of water when the slightly negative oxygen from one molecule is attracted to the slightly positive hydrogen of another molecule.
Three emergent properties of water
Cohesive Behavior, Ability to moderate temperature, Versatility as a solvent.
Cohesive Behavior
Because water is polar and forms hydrogen bonds, water molecules stick to each other, a phenomenon known as cohesion. In addition, water molecules can form hydrogen bonds with other polar molecules, resulting in water sticking to other substances, known as adhesion. These two processes result in water having a high SURFACE TENSION, and also play important roles in water transport.
Ability to moderate temperature
Because water is polar and forms hydrogen bonds, it takes a lot of energy to heat up or cool down water, known as a high specific heat capacity. Because of this, water moderates the temperature on Earth as well as within organisms.
Versatility as a solvent
Because water is polar, and forms hydrogen bonds, it is known as the universal solvent. It forms hydrogen bonds with polar or charged molecules, (hydrophilic molecules), dissolving them. Nonpolar or non-charged molecules do not dissolve in water because they do not have any charges for the negative oxygen and positive hydrogen atoms in water to interact with.
Acids
Substance that increases the H+ They have a PH balance of 0-6
Bases
Substance that decreases the H+ concentration of a solution. They have a PH balance of 8-14
Neutral
Pure water, Human blood, Tears. PH balance of 7
Buffers
Substances that minimize the H+ and OH- concentration changes in solutions. They are very important in maintaining homeostasis by moderating PH inside organisms.
