BIO/CHM 460: Biochemistry I

Thermochemical, thermophysical, and ion energetics data compiled by the National Institute of Standards and Technology (NIST).

A free access service providing a structure-centric community for chemists with millions of chemical structures and integration to a multitude of other online services, ChemSpider is the richest single source of structure-based chemistry information.

PubChem is an open chemistry database from National Institutes of Health (NIH). It provides information on chemical structures, identifiers, chemical and physical properties, biological activities, patents, health, safety, toxicity data, and many others.
You can also find links to peer-reviewed literature in PubChem.

Over 3500 enzymes are covered, classified according to the Enzyme Commission (E.C.) numbering system. The database gives a representative overview on the characteristics and variability of each enzyme but is not a compendium.

Landolt-Börnstein Substance / Property Index is the quickest and most convenient way to find information about substances and related properties. Organic Compounds are best searched by molecular formula whereas a search for element system is most suitable for inorganic substances. Syracuse University owns this reference work.

Wolfram|Alpha contains a wealth of chemistry data, and provides you with chemical computations in the context of a given search. Wolfram|Alpha is an effective learning tool for students looking for ways to learn and test their knowledge of chemistry basics.