MCAT Organic Chemistry: Functional Groups

Functional Groups in Organic Chemistry

• Alcohol: Organic compounds characterized by the presence of a hydroxyl (-OH) group.

• Aldehyde: Contains a carbonyl group (C=O) with a hydrogen atom attached, typically at the end of a carbon chain.

• Ketone: Features a carbonyl group (C=O) bonded to two carbon atoms, typically found within a carbon chain.

• Carboxylic Acid: Contains a carboxyl group (-COOH), exhibiting acidic properties due to the presence of the hydroxyl and carbonyl groups.

• Ester: Formed from a reaction between a carboxylic acid and an alcohol, characterized by the -COO- group.

• Amide: Derived from carboxylic acids where the -OH group is replaced by an amine or ammonia, featuring the -CONH2 group.

• Anhydride: Formed by the dehydration of two carboxylic acids, contains two acyl groups bound to the same oxygen atom.

Priority of Functional Groups

• Functional groups ranked in decreasing order of priority for naming:
  • Carboxylic acid
  • Anhydride
  • Ester
  • Amide
  • Aldehyde
  • Ketone
  • Alcohol
  • Alkene
  • Alkyne
  • Alkane

Common Alkyl and Acyclic Groups

• Methyl: A one-carbon (CH3) substituent derived from methane.

• Ethyl: A two-carbon (C2H5) substituent derived from ethane.

• Phenyl: A cyclic group derived from benzene, represented as C6H5; often reacts as an aromatic substituent.

• Acetyl: An important functional group derived from acetic acid, characterized by the -COCH3 structure.

Additional Functional Groups

• Enol: Contains a carbon-carbon double bond adjacent to a hydroxyl group; less stable than its keto form.

• Ether: Comprised of two alkyl or aryl groups connected through an oxygen atom (-R-O-R').

• Amino: Contains an amine group (-NH2), often a basic part of amino acids.

• Amido: Related to amides, where the functional group also includes an amine.

• Imine: Features a carbon-nitrogen double bond (C=N), formed by the condensation of an amine and a carbonyl compound.

• Schiff Base: A specific type of imine formed from the reaction of an amine and a carbonyl compound.

• Sulfhydryl: Contains a thiol group (-SH), important in the structure of some proteins and enzymes.

• Disulfide: Comprising two sulfhydryl groups that form a -S-S- bond, often found in protein structures.

• Thioester: Similar to esters, but with a sulfur atom in place of the oxygen; important in biochemical reactions.

• Phosphoryl: Involves a phosphorus atom bonded to oxygen atoms, key in energy transfer processes.

• Phosphoanhydride: Characterized by the bond between two phosphate groups, significant in ATP and energy metabolism.

Test your knowledge of key functional groups in organic chemistry with these flashcards. Familiarize yourself with their definitions and classifications to prepare efficiently for the MCAT exam.