File Name: composition structure and function of nucleic acid .zip
- DNA structure and function
- Nucleic acid
- DNA structure and function
- Learn About Nucleic Acids and Their Function
DNA structure and function
E-mail: Martine. Demeunynck ujf-grenoble. Nucleic acids are the structural supports of genetic material and therefore the key factors in many vital cellular processes. The double-stranded right-handed helix is a regular conformation adopted by both DNA and RNA in cells, but an increasing number of results point to the biological importance of alternative structures such as bulges, hairpins, branched junctions or quadruplexes. Progress in the chemical synthesis of oligonucleotides and in the knowledge of the factors that favour a particular conformation has opened new fields of research in molecular recognition and drug design. Philippe Belmont was born in Paris in Demeunynck focused on the synthesis and biological properties of heterocyclic heterodimers that recognise specific lesions in DNA.
Nucleic acids are molecules that allow organisms to transfer genetic information from one generation to the next. These macromolecules store the genetic information that determines traits and makes protein synthesis possible. Two examples of nucleic acids include deoxyribonucleic acid better known as DNA and ribonucleic acid better known as RNA. These molecules are composed of long strands of nucleotides held together by covalent bonds. Nucleic acids can be found within the nucleus and cytoplasm of our cells.
Steve Minchin, Julia Lodge; Understanding biochemistry: structure and function of nucleic acids. Essays Biochem 16 October ; 63 4 : — Nucleic acids, deoxyribonucleic acid DNA and ribonucleic acid RNA , carry genetic information which is read in cells to make the RNA and proteins by which living things function. The well-known structure of the DNA double helix allows this information to be copied and passed on to the next generation. In this article we summarise the structure and function of nucleic acids. The article includes a historical perspective and summarises some of the early work which led to our understanding of this important molecule and how it functions; many of these pioneering scientists were awarded Nobel Prizes for their work.
He reported finding a weakly acidic substance of unknown function in the nuclei of human white blood cells, and named this material "nuclein". A few years later, Miescher separated nuclein into protein and nucleic acid components. In the 's nucleic acids were found to be major components of chromosomes, small gene-carrying bodies in the nuclei of complex cells. Unlike proteins, nucleic acids contained no sulfur. Complete hydrolysis of chromosomal nucleic acids gave inorganic phosphate, 2-deoxyribose a previously unknown sugar and four different heterocyclic bases shown in the following diagram. To reflect the unusual sugar component, chromosomal nucleic acids are called deoxyribonucleic acids, abbreviated DNA.
The fourth base in RNA, however, is not thymine but instead the pyrimidine-derived base, uracil (U). The chemical structures for each of the five bases are shown.
DNA structure and function
Alongside proteins , lipids and complex carbohydrates polysaccharides , nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life. The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides. The nucleotides are joined to one another in a chain by covalent bonds known as the phospho-diester linkage between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules A with T and C with G , with hydrogen bonds to make double-stranded DNA. The complementary nitrogenous bases are divided into two groups, pyrimidines and purines.
Nucleic acid , naturally occurring chemical compound that is capable of being broken down to yield phosphoric acid , sugars, and a mixture of organic bases purines and pyrimidines. Nucleic acids are the main information-carrying molecules of the cell , and, by directing the process of protein synthesis , they determine the inherited characteristics of every living thing. DNA is the master blueprint for life and constitutes the genetic material in all free-living organisms and most viruses. RNA is the genetic material of certain viruses, but it is also found in all living cells, where it plays an important role in certain processes such as the making of proteins.
Nucleic acids are vital for cell functioning, and therefore for life.
Learn About Nucleic Acids and Their Function
Deoxyribonucleic acid DNA is a nucleic acid that contains the genetic instructions for the development and function of living things. It is often compared to a blueprint, since it contains the instructions to construct other components of the cell, such as proteins and RNA molecules. The DNA segments that carry genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the expression of genetic information. In eukaryotes such as animals and plants, DNA is stored inside the cell nucleus, while in prokaryotes such as bacteria and archaea, the DNA is in the cell's cytoplasm. Other proteins such as histones are involved in the packaging of DNA or repairing the damage to DNA that causes mutations. DNA is a long polymer of simple units called nucleotides, which are held together by a backbone made of sugars and phosphate groups.
The code within our DNA provides directions on how to make proteins that are vital for our growth, development, and overall health. DNA stands for deoxyribonucleic acid. DNA is a vitally important molecule for not only humans, but for most other organisms as well. But what does DNA actually do?
determination of structure–function relationships between DNA. and RNA Adenine and guanine are double-ring structures termed purines.
In this section, we will examine the structures of DNA and RNA, and how these structures are related to the functions these molecules perform. We will begin with DNA, which is the hereditary information in every cell, that is copied and passed on from generation to generation. The race to elucidate the structure of DNA was one of the greatest stories of 20th century science. Their famous paper, in the April 25, issue of Nature, opened the modern era of molecular biology. Arguably, that one-page paper has had more scientific impact per word than any other research article ever published. Today, every high school biology student is familiar with the double helical structure of DNA and knows that G pairs with C and A with T.
Большой Брат был частью мира, в котором царила Мидж. Он получал информацию со 148 камер кабельного телевидения, 399 электронных дверей, 377 устройств прослушивания телефонов и еще 212 жучков, установленных по всему комплексу АНБ. Директора АН Б дорого заплатили за осознание того факта, что двадцать шесть тысяч сотрудников не только огромная ценность, но и источник больших неприятностей. Все крупные провалы в сфере безопасности в истории агентства происходили внутри этого здания. В обязанности Мидж как эксперта по обеспечению внутренней безопасности входило наблюдение за всем, что творилось в стенах АНБ… в том числе и в кладовке столовой агентства. Бринкерхофф поднялся со своего места, словно стоя ему было легче защищаться, но Мидж уже выходила из его кабинета.
- Гамма-лучи против электромагнитной пульсации. Распадающиеся материалы и нераспадающиеся. Есть целые числа, но есть и подсчет в процентах. Это полная каша. - Это где-то здесь, - твердо сказала Сьюзан. - Надо думать.