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Biochemistry Functional Groups

Sep 7, 2025

Overview

This lecture reviews common functional groups and key organic chemistry concepts used in biochemistry, focusing on their properties, reactivity, and importance in biological systems.

Review of Functional Groups

  • Functional groups are specific groups of atoms that determine the reactivity of organic molecules in biochemistry.
  • Common functional groups include alcohols, carboxylic acids, esters, amides, amines, thioesters, disulfides, and phosphates.
  • Oxygen, nitrogen, sulfur, and phosphorus-containing groups are especially important in biochemical reactions.
  • Functional groups are foundational for building larger molecules and understanding biological reactivity.

The Chirality2 App for Review

  • The Chirality2 app helps review functional groups, chirality, stereoisomers, and nomenclature.
  • The app provides interactive features like drag-and-drop identification and mini-quizzes to reinforce learning.

Importance of Functional Groups in Biochemistry

  • Functional groups drive organic reactions central to life, especially in aqueous (water-based) biological environments.
  • Properties like polarity, solubility, and intermolecular forces depend on the functional groups present.
  • Acid-base properties are significant: carboxylic acids act as acids, amines as bases in biological systems.

Reaction Mechanisms in Biochemistry

  • Organic chemistry principles apply directly to biochemical reactions, especially in enzyme-catalyzed processes.
  • Understanding reaction mechanisms (electron flow, nucleophile/electrophile roles) is key for interpreting biological reactivity.
  • Reaction arrows indicate electron movement from electron-rich (nucleophile) to electron-poor (electrophile) centers.
  • Transition states are indicated by dashed lines and show partial bonds forming/breaking.
  • Enzyme mechanisms use the same rules as organic reaction mechanisms.

Polymers and Biological Macromolecules

  • Polymers (macromolecules) such as proteins and lipids are made from smaller organic building blocks.
  • Proteins have peptide (amide) backbones formed by reacting carboxylic acids with amines.
  • Understanding how functional groups link to form polymers is essential for biochemistry.

Key Terms & Definitions

  • Functional Group — A specific grouping of atoms that imparts characteristic chemical properties to a molecule.
  • Nucleophile — An electron-rich atom or group that donates electrons to an electrophile in a chemical reaction.
  • Electrophile — An electron-deficient atom or group that accepts electrons from a nucleophile.
  • Transition State — A high-energy, intermediate structure during a chemical reaction where bonds are partially formed or broken.
  • Polymer — A large molecule composed of repeating subunits (monomers).

Action Items / Next Steps

  • Review Table 1.2 and identify all listed functional groups, their names, and their structures.
  • Practice using the Chirality2 app to reinforce recognition of functional groups.
  • Study the chemical properties and reactivities of major functional groups, especially acid-base behavior.
  • Prepare for learning about the role of water and acid-base chemistry in the next section.