chapter 3- water and life + homeostasis Flashcards
what does hypertonic mean
low water concentration and high solute concentration
what does hypotonic mean
high water concentrations and low solute concentration
what is the link between hypotonic solutions and cell walls
cell walls protect the cell from rupturing when placed in a hypotonic solution
by osmosis the water would enters and the cell would swell and burst
(animal cells will rupture when left in water)
what are four (4) properties of water that contribute to life on earth
cohesive behaviour
ability to moderate temperature
expansion upon freezing
versatility as a solvent
what is cohesion
h bonds holding water molecules together
what is adhesion
attraction between different substances (ex. water and cell wall)
what is surface tension
measure of how hard it is to break the surface of a liquid
explain water’s surface tension
water’s surface tension is weirdly high due to the h bonds between the surface molecules and the lower molecules
characteristics of water regarding temperature
absorbs heat from warm air
releases heat to cold air
can absorb and release heat with little change to its own temperature
what happens temperature wise when you break the h bonds in water
it heats the water and cools the air
what happens temperature wise when you form the h bonds in water
cools water and heats the air
what is water called due to its regulation of temperature (give ex of other similar substance)
temperature buffer
blood also does this
what is thermal energy
the kinetic energy associated with the random motion of molecules
what is temperature
measure of energy that represents the average kinetic energy of molecules
what is heat
transfer of thermal energy from one body of matter to another
what is a calorie
amount of heat required to raise temperature of 1g of water by 1C (celsius)
how much is 1 joule in cal
1 J = 0.239 cal
1 cal = 4.184 J
what is specific heat
amount of heat that must be absorbed or released to get 1g of a substance to gain/lose 1 celsius
water’s specific heat
4.18 J/gC (high)
what is heat of vaporization
heat a liquid must absorb for 1g to be converted to gas
what is evaporative cooling
as a liquid evaporates its remaining surface cools (stabilizes temperature)
what are water’s characteristics concerning density
water is the densest at 4C
at 0C ice expands and gains density
ice is less dense than water (more ordered/stable h bonds) so it floats instead of sinking (which would kill every living thing)
what is the hydration shell
water molecules covering ions and molecules when they are put in water
how does water dissolve nonpolar molecules
if the molecule has ionic/polar sections the hydration shell will start dissolving it there
