Water Flashcards
What are hydrogen bonds?
The electrostatic attraction between the partial negative hydrogen atom of one molecule to the oxygen (in the instance of water) in another molecule that is partially positive
What are the characteristics of water?
Although the hydrogen bonds are relatively weak and break and reform easily they are vital for sustaining life.
Water has an unusually high boiling point compared to other small molecules such as CO2
Water becomes less dense when it freezes because the hydrogen bonds fix in position, forms a tetrahedral rigid structure
Water has cohesive properties, this is how water is drawn up into the stem of plants
Water is adhesive - water doesn’t run off hands
Capillary action
How does water being a solvent help sustain life?
- Organism can dissolve in it
- Many solutes are polar molecules, amino acids, proteins and nucleic acids, so water acts as a medium for chemical reactions and helps transport dissolved compounds into and out of cells.
- absorb mineral dissolved
- dilute toxic susbtances
How is water a coolant? Why is this important
Water helps buffer temperature changes during chemical reactions in prokaryotic and eukaryotic cells because of the large amounts of energy required to overcome hydorgen bonding.
Maintaining a constant temperature in cellular environments because enzymes are often only active in narrow temperature range.
How does water provide and constant environment for fish?
The temperature does not change very much or become a gas easily.
Ice floats on the surface of ponds and lakes, this insulates the aquatic organisms below
Its surface temperature is enough to support small insects such as pond skaters.
