unit 1, water and it's functions Flashcards
why is water described as an dipolar molecule?
-oxygen has a slight negative charge , hydrogen has a slight positive charge
-so has both a positive and negative pole therefore dipolar
how does the hydrogen bond form?
-positive hydrogen, negative oxygen so they attract
- this makes them stick together
what is specific heat capacity?
amount of energy required to heat 1kg of a substance by 1 degree
why is a lot of energy required to break the hydrogen bonds of water ?
because the specific heat capacity of water is 4200j/kg
why is the specific heat capacity of water being so high a benefit for organisms?
- buffers organisms (and environment) from sudden temperature changes
- can absorb a lot of heat, so it can still maintain its temperature which is good for enzyme activity
what is latent heat of vaporisation?
the amount of energy that must be supplied to the system to convert a unit amount of substance from the liquid to the vapor phase under conditions of equilibrium between the two phases.
why is evaporation good in mammals?
sweat is a very effective way of cooling, as body heat is used to make this water vapour
what is cohesion?
tendency of molecules sticking together
what causes cohesion in water?
the hydrogen bonds
what is an example of a strong cohesion force?
water to be pulled up xylem
what is surface tension of water?
when water meats air, the hydrogen bonds cause the formation of a film across the top of the water , eg) this causes pond skaters to float
what are 4 importances of water to organisms?
- metabolism, hydrolysis and condenstaion reactions, photosynthesis
- solvent, can readily dissolve ionic compounds and polar molecules
- provides support
- cools organsims (sweat) from evaporation
what examples are there of polar molecules or ionic compounds can water readily dissolve?
co2, o2, ammonia, urea, amino acids, monosaccharides, ATP , enzymes ( when reaction takes place in a solvent)
what is an inorganic ion?
does not contain carbon
