Water And Its Functions Flashcards
Why is water bipolar?
Water has a slightly negative oxygen and a slightly positive hydrogen so water has both positive and negative poles
Why does water contain hydrogen bonds?
The positive of one water molecule will none with the negative of another.
Without hydrogen bonds in water, water would be a gas(water vapour) and life as we know it wouldn’t exist
Why is waters specific heat capacity (4,200)so important for life?
Water acts as a buffer to sudden temperature change. This makes aquatic environments temperature stable.
As most organisms are made of water it acts a buffer for them against temperature change(especially in terrestrial environments)
A high specific heat capacity also allows the temperature of mammals to stay the same with keeps the optimal temperatures for most enzymes
Why is waters high latent heat of vaporisation so important?
Evaporation of water (sweat) in mammals is very effective at cooling down the mammal as the body heat is used to evaporate water
What is cohesion in water?
How is it important?
Water molecules sticking together.
Water can be pulled of the xylem vessel in plant(transpiration)
Adhesion (hydrogen bonds to other molecules such as cellulose) also helps with transpiration
Why is surface tension important?
Where water molecules meet air they tend to be pulled back into the body of water feather than escaping it. It’s strong enough to support pond skaters
Water in metabolism
Water is used to bread down many complex molecules by hydrolysis (proteins => amino acids)
Product of condensation
Chemical reaction take place in aqueous medium
Water is a major raw material in photosynthesis
Water as a solvent
Water dissolves enzymes whose reactions reactions take in a solution.
Chemicals dissolve into water allowing it to squeeze into smaller gaps and react.
Example:
Protein synthesis is a chemical reaction. Proteins made in this reactions make enzymes which help with digestion. Without water we would not be able to digest which would cause death
Other functions of water.
Not easily compressed so provide support for the hydrostatic skeletons of animals(earthworm)
It’s transparent and allows light through it. This allows aquatic plants to photosynthesise.
