Chemistry of Life 2 (Water and Life)

Water is a(n) _ substance because it does not contain carbon. Each water molecule contains _ atoms of hydrogen

• organic, 1

• organic, 2

• inorganic, 1

• inorganic, 2

_ bonding is found in water. These bonds involve an _ sharing of electrons due to a large electronegativity difference between hydrogen and oxygen

• Covalent, uneven

• Covalent, even

• Ionic, uneven

• Ionic, even

The partial charge of an oxygen atom in a water molecule is _ because it has a higher electronegativity than hydrogen. Water molecules as a whole are _ meaning there are is negatively and positively charged end (dipoles)

• negative, polar

• negative, nonpolar

• positive, polar

• positive, nonpolar

The polarity of water allows for _ bonding to exist between molecules. In this IMF the oxygen atom of a water molecule has a weak attraction to _ atom(s) of nearby molecules

• hydrogen, hydrogen

• hydrogen, oxygen

• covalent, hydrogen

• covalent, oxygen

Why is the polarity of water/hydrogen bonding vitally important to living things?

• It allows for thermoregulation

• It allows for cohesion and adhesion

• It allows ice to float

• It makes water an excellent solvent

• All answers are correct

_ allows water molecules to stick to surfaces. This is only possible if the surface is _

• Adhesion, polar/charged

• Adhesion, nonpolar/uncharged

• Cohesion, polar/charged

• Cohesion, nonpolar/uncharged

Cohesion and adhesion are vitally important for _ life that must must transport water for use in photosynthesis. Water is obtained through _ and moved upwards through water conducting cells

• plant, roots

• plant, leaves

• animal, roots

• animal, leaves

Water's ability to thermoregulate is due to its _ specific heat which causes water to heat up & cool down _

• high, slowly

• high, quickly

• low, slowly

• low, quickly

Water's high specific heat regulates the temperature of all of the following EXCEPT

• Oceans/ponds/lakes/etc.

• Coastal air

• Coastal land

• Inland air

Why do living things not heat up/cool down too quickly?

• 1) Living things are made up of cells

  2) Cells are made up of mostly water

  3) Water has a high specific heat

  4) Having a high specific heat means not heating up/cooling down slowly

  5) Profit

• All living things have complex mechanisms for maintaining thermoregulatory homeostasis (ex. sweating)