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DNA, RNA, Chromosomes, and Genes

DNA and RNA

How is DNA unzipped?

In 2013, researchers developed a biological computer—all with the help of human DNA. Essentially making a biological transistor—called a transcriptor— from DNA, they created a living computer. The transcriptor used a group of natural proteins that controlled how the enzyme (RNA polymerase) flowed along a DNA molecule, similar to how electrons are controlled inside an electrical wire. From there, they used something similar to a computer’s language—of 0s and 1s—to open and close logic gates, but biologically. They hope to eventually develop this living computer to take on such tasks as sensing when a cell has been exposed to a material, such as sugar—or even to tell cells to start or stop dividing depending on the stimuli in their surrounding environment.

DNA is unzipped during its replication process; the two strands of the double helix are separated and a new complementary DNA strand is synthesized from the parent strands. Also, during DNA transcription, one DNA strand, known as the template strand, is transcribed (copied) into an mRNA strand. In order for the two strands of DNA to separate, the hydrogen bonds between the nitrogen bases must be broken. DNA helicase (an enzyme) breaks the bonds. However, the enzyme does not actually unwind the DNA; special proteins first separate the DNA strands at a specific site on the chromosome, which are called initiator proteins.