Follow An Overview of DNA DNA, or deoxyribonucleic acid, is a nucleic acid that houses the genetic code that is used in the functioning and development of all living things.
This graphic provides an overview of its common structure across these life forms, and a brief explanation of how it allows proteins to be generated. DNA is found in the nucleus of cells in multicellular organisms, and was first isolated inby the Swiss physician Friedrich Miescher.
However, its structure was not elucidated until almost a century later, in This work, however, was heavily reliant on the work of another scientist, Rosalind Franklin.
Franklin herself was also investigating the structure of DNA, and it was her X-ray photograph, clearly showing the double helix structure of DNA, that greatly aided their work.
She had yet to publish her findings when Watson and Crick obtained access to them, without her knowledge. The double helix model of DNA deoxyribonucleic acid consists of two intertwined strands.
These strands are made up of nucleotides, which themselves consist of three component parts: There are four different bases that can potentially Structure of dna an overview attached to the sugar group: The bases are what allows the two strands of DNA to hold together.
Strong intermolecular forces called hydrogen bonds between the bases on adjacent strands are responsible for this; because of the structures of the different bases, adenine A always forms hydrogen bonds with thymine Twhilst guanine G always forms hydrogen bonds with cytosine C.
In human DNA, on average there are million base pairs in a single molecule — so many more than shown here! The cells in your body constantly divide, regenerate, and die, but for this process to occur, the DNA within the cell must be able to replicate itself. During cell division, the two strands of DNA split, and the two single strands can then be used as a template in order to construct a new version of the complimentary strand.
This process is carried out by a family of enzymes called DNA polymerases. When DNA is used to create proteins, the two strands must also split.
Firstly, it contains a different sugar group in the sugar phosphate backbone of the molecule: The structure of uracil is very similar to thymine, with the absence of a methyl CH3 group being the only difference. Individual amino acids, which combined make up proteins, are coded for by three letter sections of the mRNA strand.
The different possible codes, and the amino acids they code for, were summarised in a previous post that looked at amino acid structures. Some chemicals, and radiation, can induce these changes, but they can also happen in the absence of these external effects.
Though there are only 20 amino acids, the human body can combine them to produce a staggering figure of approximatelyproteins. Their creation is a continuous process, and a single protein chain can have amino acids added to it per second via the process outline above.
As the purpose of this post was primarily to examine the chemical structure of DNA, the discussion of replication and protein synthesis has been kept brief and relatively simplistic.This graphic provides an overview of its common structure across these life forms, and a brief explanation of how it allows proteins to be generated.
DNA is found in the nucleus of cells in multicellular organisms, and was first isolated in , by the Swiss physician Friedrich Miescher. The structure of DNA and RNA. DNA is a double helix, while RNA is a single helix.
Both have sets of nucleotides that contain genetic information. Review nucleic acid structure and function. Relate the tools of DNA analysis to include the use of the Internet. Use molecular techniques and Internet databases to analyze genetic material.
Understanding DNA structure and function Earlier, we compared a DNA polymer to a sentence, and the nucleotide monomers that make up a polymer to the letters . DNA is a long polymer made from repeating units called nucleotides. The structure of DNA is dynamic along its length, being capable of coiling into tight loops, and other shapes.
In all species it is composed of two helical chains, bound to each other by hydrogen bonds. Structure of DNA The double helix looks like a ladder that has been twisted at both ends. It is made of three component parts; a sugar, phosphate groups, and nitrogen bases.