DNA

Deoxyribonucleic acid (DNA) molecules are informational molecules encoding the genetic instructions used in the development and functioning of all known living organisms and many viruses. Along with RNA and proteins, DNA is one of the three major macromolecules that are essential for all known forms of life. Genetic information is encoded as a sequence of nucleotides (guanine, adenine, thymine, and cytosine) recorded using the letters G, A, T, and C. Most DNA molecules are double-stranded helices, consisting of two long polymers of simple units called nucleotides, molecules with backbones made of alternating sugars (deoxyribose) and phosphate groups, with the nucleobases (G, A, T, C) attached to the sugars. DNA is well-suited for biological information storage, since the DNA backbone is resistant to cleavage and the double-stranded structure provides the molecule with a built-in duplicate of the encoded information.

These two strands run in opposite directions to each other and are therefore anti-parallel, one backbone being 3' (three prime) and the other 5' (five prime). This refers to the direction the 3rd and 5th carbon on the sugar molecule is facing. Attached to each sugar is one of four types of molecules called nucleobases (informally, bases). It is the sequence of these four nucleobases 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. During cell division these chromosomes are duplicated in the process of DNA replication, providing each cell its own complete set of chromosomes. Eukaryotic organisms (animals, 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. 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.

Read more about DNA:  Properties, Biological Functions, Interactions With Proteins, Genetic Recombination, Evolution, History of DNA Research

Other articles related to "dna":

History of DNA Research
... Further information History of molecular biology DNA was first isolated by the Swiss physician Friedrich Miescher who, in 1869, discovered a microscopic substance in the pus of discarded surgical ... Levene suggested that DNA consisted of a string of nucleotide units linked together through the phosphate groups ... Astbury produced the first X-ray diffraction patterns that showed that DNA had a regular structure ...
Royal Jelly - Epigenetic Effects
... In spite of their identical clonal nature at the DNA level, they are strongly differentiated across a wide range of characteristics including anatomical and physiological differences ... It has been shown that this phenomenon is mediated by an epigenetic modification of DNA known as CpG methylation ... Silencing the expression of an enzyme that methylates DNA in newly hatched larvae led to a royal jelly-like effect on the larval developmental trajectory the majority of individuals with reduced DNA ...
Filter Binding Assay
... affinities between two molecules (often protein and DNA) using a filter ... DNA is negatively charged due to the phosphate backbone and will not "stick" to the nitrocellulose on its own, however, any DNA that has been bound by ... The exact amount of DNA "stuck" to the nitrocellulose is quantified by measuring the amount of radioactivity on the filter using a scintillation counter Protein and DNA are mixed in a ...
DNA Lounge - History
... it was purchased by Jim English, Jeff Mason, and Brian Raffi who opened for business under the name DNA Lounge on November 22, 1985 ... Many of DNA's posters and flyers were designed by the San Francisco-based artist, Rex Ray ... During the early 90s, the DNA offered a black membership card for $10 that offered free entry most nights ...
Flow Cytometry - Measurable Parameters
... cell pigments such as chlorophyll or phycoerythrin total DNA content (cell cycle analysis, cell kinetics, proliferation, ploidy, aneuploidy, endoreduplication, etc.) total RNA content DNA copy number variation (b ...

Famous quotes containing the word dna:

    Here [in London, history] ... seemed the very fabric of things, as if the city were a single growth of stone and brick, uncounted strata of message and meaning, age upon age, generated over the centuries to the dictates of some now all-but-unreadable DNA of commerce and empire.
    William Gibson (b. 1948)