Skip to main content

What is DNA?

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA) 
Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.
DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.
An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.

DNA profiling
Deoxyribozymes, also called DNAzymes or catalytic DNA, are first discovered in 1994.[163] They are mostly single stranded DNA sequences isolated from a large pool of random DNA sequences through a combinatorial approach called in vitro selection or systematic evolution of ligands by exponential enrichment (SELEX). DNAzymes catalyze variety of chemical reactions including RNA-DNA cleavage, RNA-DNA ligation, amino acids phosphorylation-dephosphorylation, carbon-carbon bond formation, and etc. DNAzymes can enhance catalytic rate of chemical reactions up to 100,000,000,000-fold over the uncatalyzed reaction.[164] The most extensively studied class of DNAzymes is RNA-cleaving types which have been used to detect different metal ions and designing therapeutic agents. Several metal-specific DNAzymes have been reported including the GR-5 DNAzyme (lead-specific),[163] the CA1-3 DNAzymes (copper-specific),[165] the 39E DNAzyme (uranyl-specific) and the NaA43 DNAzyme (sodium-specific).[166] The NaA43 DNAzyme, which is reported to be more than 10,000-fold selective for sodium over other metal ions, was used to make a real-time sodium sensor in living cells.


Comments

Post a Comment

Popular posts from this blog

What is DNA Barcoding?

What is DNA Barcoding? DNA barcoding first came to the attention of the scientific community in 2003 when Paul Hebert's research group at the University of Guelph published a paper titled "Biological identifications through DNA barcodes". In it, they proposed a new system of species identification and discovery using a short section of DNA from a standardized region of the genome. That DNA sequence can be used to identify different species, in the same way a supermarket scanner uses the familiar black stripes of the UPC barcode to identify your purchases. The gene region that is being used for almost all animal groups, a 648 base-pair region in the mitochondrial cytochrome c oxidase 1 gene ("CO1"), is proving highly effective in identifying birds, butterflies, fish, flies and many other animal groups. The advantage of using COI is that it is short enough to be sequenced quickly and cheaply yet long enough to identify variations among species. The COI bar...
Post a Comment
Read more

DNA barcoding

DNA barcoding  is a  taxonomic  method that uses a short genetic marker in an organism's DNA to identify it as belonging to a particular  species . [1]  It differs from  molecular phylogeny in that the main goal is not to determine patterns of relationship but to identify an unknown sample in terms of a preexisting classification. [2]  Although barcodes are sometimes used in an effort to identify unknown species or assess whether species should be combined or separated, [3]  the utility of DNA barcoding for these purposes is subject to debate. [4]  The most commonly used barcode region for animals and  protists  is a segment of approximately 600  base pairs  of the  mitochondrial  gene  cytochrome oxidase I  (COI). This differs in the case of  fungi , where part of  Internal Transcribed Spacer  2 ( ITS2 ) between  rRNA  genes is used, and again in plants, where multiple region...
Post a Comment
Read more

ADOBE DREAMWEAVER CS4 TUTORIAL

Before you get started, it is important that you have a space to upload your Web site When it is completed. BGSU offers 15 MB of free personal Web space for each student, so you can use this space to upload your project. https://drive.google.com/file/d/0B6c5DQEvx6ivY2lxUHNJN1I1d28/view
Post a Comment
Read more