First 204 words of the document:
Water is Essential to Living Organisms
Makes up about 80% of cells contents
Is a reactant in lots of chem. reactions e.g. photosynthesis &
Is a solvent substances dissolve in it. Most biological reactions take
place in solution.
Transports substances. Liquid + solvent = easily transport materials
e.g. glucose/oxygen around plants/animals.
Helps temp control. Carries away heat energy when evaporated from
surface, therefore cools surface + helps lower temp.
Water Molecules have a Simple Structure
Molecule of water 1 atom of oxygen (O) joined to 2 atoms of
hydrogen (H2) by shared electrons = H2O
Shared negative H electrons are pulled towards O atom. Other side of
H atom left with a slight positive charge.
Unshared negative electrons on the O atom give it a slight negative
Makes water a polar molecule a negative charge on one
side, positive charge on the other.
Negatively charged O atoms of water attract positively charged H
atoms of other water molecules.
The attraction is called hydrogen bonding gives water some of its
Other pages in this set
Here's a taster:
Hydrogen Bonds Give Water a High Specific Heat Capacity
Specific heat capacity the energy needed to raise the temperature
of 1g of a substance by 1oC.
H bonds between water molecules can absorb a lot of energy.
So water has a high specific heat capacity needs a lot of energy to
Useful for living organisms b/c it stops rapid temp changes keeps
temp fairly stable.…read more