outubro 18, 2007

What is DNA?

What is DNA?

"Your DNA is like your thumbprint. It is yours and yours alone. Unless you have an identical twin, no one else on the planet has exactly the same DNA as you.
In the nucleus of almost every cell in your body is the collection of DNA needed to make you. DNA in the nucleus is grouped into 23 sets of chromosomes that are called your "genome." In each chromosome, the DNA is grouped into "genes." Your genome contains about 35,000 genes. Each gene carries information that tells the cell to make a unique protein that will perform a special function.
How does something so small contain all of the instructions to make your whole body and keep it working? That is answered in the chemical makeup of DNA. If you think of your genome (all of your chromosomes) as the book that makes you, then the genes are the words that make up the story. They do that by making proteins, which do most of the real work in the body. The DNA in your genes tells the cell what amino acids (protein building blocks) to put together to make a protein. The letters that make up the words are called DNA bases, and there are only four of them: adenine(A), guanine(G), cytosine(C), and thymine(T). It's hard to believe that an alphabet with only four letters can make something as wonderful and complex as a person!"

Fifty years ago, on Saturday, Feb. 28, 1953, two young scientists walked into the Eagle, a dingy pub in Cambridge, England, and announced to the lunchtime crowd that they had discovered the secret of life.
By divining the chemical structure of DNA, the archive of life, James D. Watson and Francis Crick had seen how the molecule could encode information in the copious quantities necessary to program a living cell.

The names Watson and Crick, it has been said, have “joined Darwin and Copernicus among the immortals”. The pair’s discovery of the structure of DNA, in 1953, has been hailed by fellow Nobel laureates as the greatest single scientific achievement of the 20th century.
After figuring out the structure of DNA, Dr. Crick and Dr. Watson realized that the sequence of units in the DNA must carry the code in some way for the structure of the proteins that are the working parts of a cell. But they did not foresee that the entire genomes would one day be decoded.

Human Genome Project

National Center for Biotechnology Information (NCBI)
Fifty years after the double helix, the reference DNA sequence of Homo sapiens is now available for downloading. Human genome projects have generated an unprecedented amount of knowledge about human genetics and health.

The Human Genome Project is a publicly financed international research effort whose goal is to decipher the human genetic code and to provide these data freely and rapidly to the public. On June 26, 2000, members of the Human Genome Project announced that they had succeeded in sequencing a "working draft" of the human genome.

Sequencing of the human genome represents a scientific milestone, and the data are of immediate use in many important ways. To further understand and use the information coded for in this "human blueprint", the National Center for Biotechnology Information (NCBI) provides access to this data worldwide through its public Web site


Anyone with a computer and an Internet connection can now explore the draft sequence of the human genome.

ex. Human chromosome y

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