Bite-Sized Morsels of Biology that are Good and Good For You
Water Molecules are Polar
Water molecules have a positive side (hydrogen) and a negative side (oxygen) that attract and repel molecules with opposite or like charges.
-
Polar Covalent Bonds share electrons closer to oxygen than hydrogen
-
Water molecules form hydrogen bonds between themselves
-
Non-polar molecules don't mix with water because water is so attracted to itself.
Water Molecules
When water molecules form, the electrons (which are always moving) tend to stay above the imaginary green line.
-
Electrons are negative, and outnumber the positive protons in the oxygen nucleus 10 to 8 making the oxygen side more negative.
-
Below the green line, there are usually only protons in the hydrogen nuclei making the hydrogen side positive.
-
For more on polar covalent bonds, click here.
Hydrogen Bonds
One water molecule is held together by polar covalent bonds. Many water molecules are held together by hydrogen bonds.
-
The positive hydrogen side is attracted to the negative oxygen side.
-
This is a weak bond that is easily broken and reformed like two magnets
-
Water molecules are constantly moving, but instead of moving in straight lines, they are pulled toward and away from each other based on the charges that are nearest each other
Water and Non-Polar Molecules
Non-polar molecules do not have positive or negative charges, and they do not mix well with water.
-
Lipids, like oils and fats, are non-polar
-
Water does not necessarily repel such molecules, but because water molecules are attracted to each other, the lipids tend to clump near each other
