22.7.08

Untuk Pengetahuan: WHAT IS DNA?


DNA, or deoxyribonucleic acid, is the fundamental building block for an individual's entire genetic makeup. It is a component of virtually every cell in the human body.(1
Further, a person's DNA is the same in every cell. For example, the DNA in a man's blood is the same as the DNA in his skin cells, semen, and saliva.(2
The DNA Double Helix is one of the greatest scientific discoveries of all time. First described by James Watson and Francis Crick in 1953, DNA is the famous molecule of genetics that establishes each organism's physical characteristics.(3
It wasn't until mid-2001, that the Human Genome Project and Celera Genomics jointly presented the true nature and complexity of the digital code inherent in DNA.(4
We now understand that there are approximately 35,000 genes in each human DNA molecule, comprised of chemical bases arranged in approximately 3 billion precise sequences.(5
Even the DNA molecule for the single-celled bacterium, E. coli, contains enough information to fill all the books in any of the world's largest libraries.(6
DNA (deoxyribonucleic acid) is a double-stranded molecule that is twisted into a helix like a spiral staircase. Each strand is comprised of a sugar-phosphate backbone and numerous base chemicals attached in pairs.(7
he four bases that make up the stairs in the spiraling staircase are adenine (A), thymine (T), cytosine (C) and guanine (G). These stairs act as the "letters" in the genetic alphabet, combining into complex sequences to form the words, sentences and paragraphs that act as instructions to guide the formation and functioning of the host cell.(8
Maybe even more appropriately, the A, T, C and G in the genetic code of the DNA molecule can be compared to the "0" and "1" in the binary code of computer software. Like software to a computer, the DNA code is a genetic language that communicates information to the organic cell.(9
The DNA code, like a floppy disk of binary code, is quite simple in its basic paired structure. However, it's the sequencing and functioning of that code that's enormously complex.(10
Through recent technologies like x-ray crystallography, we now know that the cell is not a "blob of protoplasm", but rather a microscopic marvel that is more complex than the space shuttle.(11
The cell is very complicated, using vast numbers of phenomenally precise DNA instructions to control its every function.(12

No comments: