A1.1 water Flashcards
why is water a polar molecule
Water is a polar molecule due to the uneven sharing of electrons between oxygen and hydrogen atoms.
-slight negative charge at oxygen end of molecule
the structure of diagram for a water molecule
-polar covalent bonds between oxygen atom and two hydrogen atoms
-O =δ-
- H= δ+
-IMF’s between water molecules
importance of liquid water
- is a solvent needed for reactions to occur
-allows dissolved molecules to move around
-makes up fluid in cytoplasm and in the organelles
-allows transports of substances in and out of cells
-essential for blood and other bodily fluids
-provides medium for all living organisms
when does cohesion occur
when molecules of the same type are attracted to each other
what is hydrogen bonding
when two water molecules are near each other, the positive end of one water molecule attracts the negative end of another, creating a hydrogen bond
why water has surface tension
(the capacity of a substance to withstand being ruptured under pressure)
-water has strong cohesive forces to the molecules around it and below them
-surface tension must be broken for object to move through
how water moves up the xylem
-water is transported through plants through cohesive and adhesive forces, pulling water from roots to leaves
-tension pulls water molecules in xylem up to leaf. These molecules are cohesive to each other, making a transpiration stream, moving to stomata
what is adhesion
the attraction between two unlike molecules due to hydrogen bonding
adhesion in plant cell walls and capillary action
- adhesion between water and polar cellulose molecules in cell wall, keeping the column from dropping
-polar molecules in porous soil adheres to water molecules
aqueous solution
any solution that has water as its solvent
hydrophilic
substances that can dissolve in water
-glucose, ions, enzymes
hydrophobic
substances that cant easily dissolve in water
-steriod hormones, epidermal cells
capillary action
the movement of a liquid through or along another material against an opposing force
physical properties of water and its affects on aquatic animals
1) Buoyancy- allows animals to float and preserve energy
black throated loon=relies on buoyancy to swim and can adjust the density of lung volume
ringed seal= layer of blubber allows buoyancy
2) viscosity= measure of flow influencing motion
loon= webbed feet and streamlined body to dive
seal= streamlined body, paddled feet for feeding
3) thermal heat conductivity in water is high
helps with efficient transfer of hear in cold environments
loon=has feathers and hydrophilic oil layers to allow heat loss
seal= layer of blubber maintaining heat
4) specific heat capacity is high in water
-can release/ absorb more heat energy, helps with homeostasis since there is smaller range of temperatures
loon= the water is warmer and more stable due to high shc
seal= protection from cold air, like loon
metabolism
- all the reactions that take place in an organism, it is controlled by enzymes and occur in aqueous solutions
