User:Eloquence/Tour 01

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Welcome to the Wikipedia tour. My name is Denis, and I will be your guide. This trip will show you the diversity of the content on Wikipedia, some of its most unusual articles, the inner workings of the project, its policies and debates, and everything you need to know to become a contributor. Don't worry about getting lost - I will be with you during the whole trip.

What you see below is the Main Page of Wikipedia. You've probably seen it before, but pay a closer look. Much of the content below is updated daily by our open community of editors. The featured article, for example, is picked from the list of featured articles. These are pages which have undergone a community review process. The Did you know section in the lower right comes exclusively from our latest article additions. Also take a look at all the other languages Wikipedia is available in!



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Today's featured article

HIV protease in a complex with the protease inhibitor ritonavir

Enzyme inhibitors are molecules that bind to enzymes and decrease their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. Inhibitor binding is either reversible or irreversible. Irreversible inhibitors usually react with the enzyme and change it chemically. These inhibitors modify key amino acid residues needed for enzymatic activity. In contrast, reversible inhibitors bind non-covalently and different types of inhibition are produced depending on whether these inhibitors bind the enzyme, the enzyme-substrate complex, or both. Their discovery and improvement is an active area of research in biochemistry and pharmacology. A medicinal enzyme inhibitor is often judged by its specificity (its lack of binding to other proteins) and its potency (its dissociation constant, which indicates the concentration needed to inhibit the enzyme). A high specificity and potency ensure that a drug will have few side effects and thus low toxicity. Enzyme inhibitors also occur naturally and are involved in the regulation of metabolism. (more...)

Recently featured: Mormon handcart pioneersHistory of the board game MonopolyFundamental Rights, Directive Principles and Fundamental Duties of India

Did you know...

From Wikipedia's newest articles:

Work

In the news

The Chinese River Dolphin

On this day...

December 15: Hanukkah begins at sunset (Judaism, 2006); Zamenhof Day

The United States Constitution

Recent days: December 14December 13December 12

Today's featured picture

Petrified wood

Petrified wood, such as this sample found in Petrified Forest National Park, Arizona, United States, is a fossil wood where all the organic materials have been replaced with minerals, while retaining the original structure of the wood. The petrifaction process occurs underground, when wood becomes buried under sediment. Mineral-rich water flowing through the sediment deposits minerals in the plant's cells and as the lignin and cellulose decay, a stone cast forms in its place.

Photo credit: Daniel Schwen
Archive - More featured pictures...

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This Wikipedia is written in English. Started in 2001, it currently contains 1,533,902 articles. Many other Wikipedias are available; the largest are listed below.

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