MOLECULES IN BIOLOGY

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 groupoften 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 formationlink 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 substancesmust 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 shapesignals 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

Waterhydrogen 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

Dissolvingwater’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