A1.1 - Water Flashcards
characteristics of water
polar molecule, universal solvent, found inside & outside cells, facilitates chemical communication
characteristics of water as habitat
adv: provides bouyancy & stable thermal properties
disadv: high viscosity
characteristics of water (where is it found, functions, etc)
found in cytoplasm
permits transport of cells in & out
essential to blood
provides habitat
found in intercellular tissue
polar covalent bond
unequal sharing of electrons results in slightly positive and slightly negative charge ends due to difference in electron density
ephemeral bond
temporary weak attraction = hydrogen bond between hydrogen and electronegative atom
cohesion
molecules fo the same type are attracted to each other
impacts of cohesion
surface tension
movement of water in xylem
what is surface tension
layers of water molecules on the surface of the water have to molecules above them, but have a strong cohesive force around them forming tension which must be broken to penetrate surface
xylem
vascular tissue of plants
movement of water in xylem
roots take in water
water is pulled up through xylem due to cohesion and tension
water evaporates through transpiration out of stomato
adhesion
attraction betwen 2 unlike molecules due to hydrogen bonding (ex: hydrogen & oxygen in water molecule)
influences of adhesion
water movement within xylem
capilary action in soil
capillary action due to adhesion
column of water pulled up = adhesion prevents water dropping back down tube
capillary action in soil due to cohesion
water in micrscopic channels will adhere to polar mmolecules in soil and move up through cohesion
hydrophilic substance
substances that dissolve readily in water
hydrophobic substances
substances that do not dissolve readily in water
examples of hydrophilic molecules
glucose, ions, amino acids, enzymes
what solutes does water transport as an aqueous solvent
water in xylem transports inorganic solutes like sodium, potassium and calcium,
blood transports WBC + RBC in plasma
examples of hydrophobic molecules
steroid hormones, proteins, cuticle wax (epidermal leaves)
physical properties of water
bouyancy, viscosity, specific heat capacity, thermal conductivity
bouyancy
upwards force exterted on object placed in medium; weight of water displaced by an object
viscosity
measure of fluid’s resistance to flow; thin liquid = low viscosity
thermal conductivity
ability of a substance to transfer heat
specific heat capacity
ability to absorb & store large amounts of heat with small change in temperature
