On the Human Genome

The human genome is encoded by 3 billion base pairs of DNA. A base pair is like a computer bit, only there are four of them (A, T, G, and C) instead of two (1 and 0). So, it would take two computer bits to record one base pair (00=A, 11=T, 10=G, 01=C). If we recorded the human genome as bits instead of base pairs, it would take 6 billion bits. This translates into about 715 megabytes. That's more than a CD can hold!

Nearly every cell in the human body contains this genome, and there are about 10 trillion cells in the body. The entire genome is crammed into the nucleus of each cell, which is only 5 micrometers (0.005mm) in diameter. The best electronics still don't even come close to what nature can do.

CD Cell
This is a picture I took with an electron microscope of a human cell on an America Online CD I peeled apart. A CD can hold 5.5 billion of these dots and dashes that encode the 1's and 0's of digital data. This HeLa cell not only contains as much information as a CD, but it can also decode and execute its instructions, similar to what your computer does with a CD. (Scale Bar 30 microns)

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Written June 10, 2004