Chapter 3: Water and Life Flashcards
is the only common substance to exist in the
natural environment in all three physical states of
matter
water
spend more time near the oxygen
than the hydrogen
polar covalent bonds
Four of water’s properties that facilitate an
environment for life are
Cohesive behavior
Ability to moderate temperature
Expansion upon freezing
Versatility as a solvent
Collectively, hydrogen bonds hold water molecules
together, a phenomenon called
cohesion
helps the transport of water against gravity
in plants
cohesion
is an attraction between different
substances, for example, between water and plant
cell walls
adhesion
is a measure of how difficult it is to
break the surface of a liquid
Surface tension
is the energy of motion
kinetic energy
The kinetic energy associated with random motion of
atoms or molecules is called what
thermal energy
represents the average kinetic energy
of the molecules in a body of matter
temperature
Thermal energy transfered from one body of
matter to another is defined as
heat
s the amount of heat required to
raise the temperature of 1 g of water by 1ºC
calorie (cal)
The “Calories” on food packages are actually
kilocalories (kcal)
is transformation of a
substance from liquid to gas
Evaporation (or vaporization)
is the heat a liquid must
absorb for 1 g to be converted to gas
Heat of vaporization
As a liquid evaporates, its remaining surface cools, a
process called
evaporative cooling
evaporative cooling
As a liquid evaporates, its remaining surface cools, a
process called
Water reaches its greatest density at what temperature
4ºC
is a liquid that is a completely
homogeneous mixture of substances
solution
is the dissolving agent of a solution
solvent
is the substance that is dissolved
solute
solution is one in which water is the
solvent
aqueous solution
Water is a versatile solvent due to its what
polarity
solute
is the substance that is dissolved
solvent
is the dissolving agent of a solution
solution
is a liquid that is a completely
homogeneous mixture of substances
When an ionic compound is dissolved in water, each
ion is surrounded by a sphere of water molecules
called a
hydration shell
hydration shell
When an ionic compound is dissolved in water, each
ion is surrounded by a sphere of water molecules
called a
substance is one that has an
affinity for water
hydrophilic
hydrophilic
substance is one that has an
affinity for water
substance is one that does not have
an affinity for water
hydrophobic
the major
ingredients of cell membranes
Hydrophobic molecules related to oils
The hydrogen atom leaves its electron behind and is
transferred as a proton,
hydrogen ion (H+)
Biologists use the what to describe whether a
solution is acidic or basic (the opposite of acidic)
ph scale
is a substance that increases the H+
concentration of a solution
acid
is a substance that reduces the H+
concentration of a solution
base
Strong acids and bases dissociate completely
in what?
water
Acidic solutions have this pH values
less than 7
have pH values greater than 7
bases
have pH values less than 7
acids
Most biological fluids have pH values in the range of
6 to 8
is the main product of fossil fuel combustion
CO2
CO2 dissolved in seawater forms carbonic acid; this process is called what
ocean acidification
is required for calcification
carbonate
