Portal:Chemistry

Enzymes are known to catalyze about 4,000 reactions. However, not all biological catalysts are proteins, since some RNA molecules called ribozymes can also catalyze reactions. Enzymes are usually named according to the reaction they catalyze. Typically the suffix -ase is added to the name of the substrate (e.g., lactase is the enzyme that cleaves lactose) or the type of reaction (e.g., DNA polymerase forms DNA polymers).

Like all catalysts, enzymes work by providing an alternative path of lower activation energy for a reaction and dramatically accelerating its rate. Some enzymes can make their conversion of substrate to product occur many millions of times faster. For example, the reaction catalysed by orotidine 5'-phosphate decarboxylase will consume half of its substrate in 78 million years if no enzyme is present. However, when the decarboxylase is added, the same process takes just 25 milliseconds. Chemically, enzymes are like any catalyst and are not consumed in chemical reactions, nor do they alter the equilibrium of a reaction. However, enzymes do differ from most other catalysts by being much more specific.

Enzyme activity can be affected by other molecules. Inhibitors are molecules that decrease enzyme activity, and activators are molecules that increase activity. Drugs and poisons are often enzyme inhibitors.

Some enzymes are used commercially, for example, in the synthesis of antibiotics. In addition, some household cleaning products use enzymes to speed up chemical reactions (e.g., enzymes in biological washing powders break down protein or fat stains on clothes).

Fields of Chemistry

• Analytical chemistry: Chromatography, Spectroscopy
• Biochemistry: Molecular biology
• Crystal Chemistry
• Environmental chemistry: Geochemistry
• Inorganic chemistry: Inorganic reactions
• Materials science: Nanotechnology, Glass, Ceramics
• Medicinal chemistry
• Metallurgy
• Nuclear chemistry
• Organic chemistry: Functional groups, Organic compounds, Organic reactions
• Organometallic chemistry
• Pharmacy
• Physical chemistry: Electrochemistry, Quantum chemistry
• Polymer chemistry
• Supramolecular chemistry
• Theoretical chemistry: Computational chemistry

Many chemists have an interest in the history of chemistry. Those with philosophical interests will be interested that the philosophy of chemistry has quite recently developed along a path somewhat different from the general philosophy of science.

Other articles that might interest you are:

• Superseded chemistry theories
• Alchemy
• Scientific method
• The central science

There is a Wikipedia Project on the History of Science.

Wikipedia:WikiProject Chemicals/Data is a collection of links and references that are useful for chemistry-related works. This includes free online chemical databases, publications, patents, computer programs, and various tools.

unit-conversion.info A good place to figure out what equals what.

General Chemistry Online Clear text and comprehensive coverage of general chemistry topics by Fred Senese, Dept. of Chemistry Frostburg State University

General Chemistry Demonstration at Purdue Video clips (and descriptions) of lecture demonstrations.

Chemistry Webercises Directory A large listing of chemistry resources maintained by Steven Murov, Emeritus Chemistry Professor Modesto Junior College.

MathMol MathMol (Mathematics and Molecules) is a good starting point for those interested in the field of molecular modeling.

ABC-Chemistry A directory of free full-text journals in chemistry, biochemistry and related subjects.

The Element Song A goofy little song about all of the elements.