A solution = A mixture of two or more different substances where the liquid is
Solvent = The dissolving agent of a solution.
Solute = The substance that is dissolved
Aqueous solution = a substance in which water is the solvent
Ie- Sugar in water- water is solvent and sugar is the solute.
Hydration shell = The sphere of water molecules around each ion.
- The dissociation of water molecules occurs when a hydrogen atom shared by two
water molecules in a hydrogen bond shifts from one molecule to the other. The
hydrogen atom leaves its electron behind and a hydrogen ion is transferred. In the
end get H+ and OH-
- In water concentration of each ion is 10^-7
- This is important as the dissociation of water molecules can change the pH of an
animal and its environment.- ie when this balance is disrupted with the adding of
other solutes to make the water impure.
- Buffers= Enable biological fluids to resist changes to their own pH when acids
and bases are introduced. – minimize changes in the concentrations of OH- and
H+- the buffer accepts Hydrogen ions from the solution when they are in excess
and donating hydrogen ions when they have been depleted. Ie- H2Co3 (most
buffers are acid-base pairs)
- Variation in carbon skeletons contributes to the diversity of organic molecules.
Hydrocarbons = organic molecules consisting only of carbon and hydrogen.
Different structures, sizes, branching, rings etc will all determine the nature of the
ie- Petroleum, needed for fossil fuels.
Store a large amount of energy.
- Structural isomers= differ in covalent arrangements of their atoms
- Geometric isomers = have the same covalent partnerships but they differ in their
- Enantiomers = Molecules that are mirror images of each other. – different cells
will react differently to such molecules. Ie- one may be a more effective drug than
- Functional groups contribute to the molecular diversity of life.
- Most commonly involved in chemical reactions.
- Most important =
- Hydroxyl, OH Alcohols
- Carbonyl, CO Called an aldehyde or a ketone.
- Carboxyl, COOH Carboxylic acids (source of hydrogen ions thus- acidic
- amino, NH2 amines