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[[Chemical]]ly, DNA consists of two long polymers of simple units called nucleotides, with backbones made of sugars and phosphate [[group]]s joined by ester bonds. These two strands run in opposite directions to each other and are therefore anti-[[parallel]]. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a [[process]] called transcription.

[[Chemical]]ly, DNA consists of two long polymers of simple units called nucleotides, with backbones made of sugars and phosphate [[group]]s joined by ester bonds. These two strands run in opposite directions to each other and are therefore anti-[[parallel]]. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a [[process]] called transcription.

Within cells, DNA is organized into long structures called [[chromosomes]]. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic [[organism]]s ([[animal]]s, plants, fungi, and protists) store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts.[1] In contrast, prokaryotes (bacteria and archaea) store their DNA only in the [[cytoplasm]]. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.[http://en.wikipedia.org/wiki/DNA]

Within cells, DNA is organized into long structures called [[chromosomes]]. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic [[organism]]s ([[animal]]s, plants, fungi, and protists) store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts.[1] In contrast, prokaryotes (bacteria and archaea) store their DNA only in the [[cytoplasm]]. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.[https://en.wikipedia.org/wiki/DNA]

==References==

==References==

# Russell, Peter (2001). iGenetics. New York: Benjamin Cummings. ISBN 0-805-34553-1.

# Russell, Peter (2001). iGenetics. New York: Benjamin Cummings. ISBN 0-805-34553-1.

*Olby, Robert C. (2009). Francis Crick: A Biography. Plainview, N.Y: Cold Spring Harbor Laboratory Press. ISBN 0-87969-798-9.

*Olby, Robert C. (2009). Francis Crick: A Biography. Plainview, N.Y: Cold Spring Harbor Laboratory Press. ISBN 0-87969-798-9.

==External links==

==External links==

* [http://pipe.scs.fsu.edu/displar.html DNA binding site prediction on protein]

* [https://pipe.scs.fsu.edu/displar.html DNA binding site prediction on protein]

* [http://biostudio.com/c_%20education%20mac.htm DNA coiling to form chromosomes]

* [https://biostudio.com/c_%20education%20mac.htm DNA coiling to form chromosomes]

* [http://www.dnaftb.org/dnaftb/ DNA from the Beginning] Another DNA Learning Center site on DNA, genes, and heredity from Mendel to the human genome project.

* [https://www.dnaftb.org/dnaftb/ DNA from the Beginning] Another DNA Learning Center site on DNA, genes, and heredity from Mendel to the human genome project.

* [http://ca.youtube.com/watch?v=iyb7fwduuGM DNA Lab, demonstrates how to extract DNA from wheat using readily available equipment and supplies.]

* [https://ca.youtube.com/watch?v=iyb7fwduuGM DNA Lab, demonstrates how to extract DNA from wheat using readily available equipment and supplies.]

* [http://nobelprize.org/educational_games/medicine/dna_double_helix/ DNA the Double Helix Game] From the official Nobel Prize web site

* [https://nobelprize.org/educational_games/medicine/dna_double_helix/ DNA the Double Helix Game] From the official Nobel Prize web site

* [http://www.fidelitysystems.com/Unlinked_DNA.html DNA under electron microscope]

* [https://www.fidelitysystems.com/Unlinked_DNA.html DNA under electron microscope]

* [http://www.dnalc.org/ Dolan DNA Learning Center]

* [https://www.dnalc.org/ Dolan DNA Learning Center]

* [http://www.nature.com/nature/dna50/archive.html Double Helix: 50 years of DNA], ''[[Nature (journal)|Nature]]''

* [https://www.nature.com/nature/dna50/archive.html Double Helix: 50 years of DNA], ''[[Nature (journal)|Nature]]''

* [http://www.ncbe.reading.ac.uk/DNA50/ Double Helix 1953–2003] National Centre for Biotechnology Education

* [https://www.ncbe.reading.ac.uk/DNA50/ Double Helix 1953–2003] National Centre for Biotechnology Education

[[Category: Biology]]

[[Category: Biology]]

[[Category: Chemistry]]

[[Category: Chemistry]]