Functional Groups  a part of the molecule that stands out as an unusual or unique part of the molecule  the molecule often has certain characteristics based on a functional group  the entire molecule is often named according to the functional group they contain  “R” in a structural formula of a molecule just stands for any other atoms other than the functional group often referred to as a “side chain” Geeky website on functional groups click here

Carboxyl

Ester  appropriately called esters if have O=C O

Ketone

Hydroxyl  molecules containing this (OH) are called alcohols

Amine

 the molecular subunits/building blocks of proteins (the essential building blocks for living organisms)  20 different amino acids are used to synthesize almost all the proteins in almost all living cells Amino Acids/Proteins

 protein formation link is between carboxyl group on one a.a. and the amino group on the other. water is formed and remaining N and C link together called a peptide bond

Protein movie

 humans can tell the difference between 10,000 different odors  a more distant sense allowing us to detect small concentrations of airborne substances must be a gas ○ therefore cannot smell ionic compounds since they are normally solids at room temperature  molecules fit into certain receptors sites in the human body as a result of their shape signals are then sent to the brain Smells

 compounds that have similar smells have similar structural formulas  polar molecules may “stick” to receptor sites better than non-polar

 Water hydrogen bonding ○ occurs when positively charged hydrogens are weakly attracted to the unshared electron pairs of another atom ○ in water, the positive H is often attracted to the negative oxygen

 Dissolving water’s polarity allows it to dissolve ionic compounds (+ and -) and polar covalent molecules ( ƺ + or ƺ -) ○ “like dissolves like” life on Earth is based on this