Carbon and Functional Groups

Organic molecule

Any carbon-containing liquid, solid, or gas (must have C-H and/or C-C bonds; CO2 is NOT organic)

Carbon bonding capacity

Carbon is unique because it forms covalent bonds to as many as four different atoms

Carbon backbone

Carbon serves as the "backbone" or skeleton of macromolecules

Hydrocarbon

Molecule that consists only of carbon and hydrogen (e.g., propane, butane, methane)

Hydrocarbon structures

Hydrocarbons can exist as linear chains (branched or unbranched), carbon rings, or combinations of both

Carbon-carbon bonds

Carbon-carbon bonds can be single, double, or triple; the type affects the molecule's geometry

Functional group

Groups of atoms that occur within molecules and confer specific chemical properties to those molecules

Location of functional groups

Found along the "carbon skeleton" or backbone of macromolecules

Hydroxyl group structure

-OH (oxygen bonded to hydrogen)

Hydroxyl group properties

Polar, hydrophilic, forms hydrogen bonds (found in alcohols)

Methyl group structure

-CH3 (carbon bonded to three hydrogens)

Methyl group properties

Nonpolar, hydrophobic, affects gene expression (found in methylated DNA)

Carbonyl group structure

C=O (carbon double-bonded to oxygen)

Carbonyl group properties

Polar, hydrophilic (found in ketones and aldehydes)

Carboxyl group structure

-COOH (carbon double-bonded to oxygen and single-bonded to hydroxyl group)

Carboxyl group properties

Acidic (donates H+), polar, hydrophilic (found in amino acids and fatty acids)

Amino group structure

-NH2 (nitrogen bonded to two hydrogens)

Amino group properties

Basic (accepts H+), polar, hydrophilic (found in amino acids)

Phosphate group structure

-PO4 (phosphorus bonded to four oxygens)

Phosphate group properties

Acidic, negatively charged, polar, hydrophilic, transfers energy (found in ATP, DNA, RNA)

Sulfhydryl group structure

-SH (sulfur bonded to hydrogen)

Sulfhydryl group properties

Polar, forms disulfide bridges to stabilize protein structure (found in cysteine)