File Name: molecular structure of dna and rna .zip
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- Nucleic acid structure
- DNA, RNA, Protein, and Gene Expression
- DNA and RNA
DNA deoxyribonucleic acid is the genomic material in cells that contains the genetic information used in the development and functioning of all known living organisms.
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It contains the information the cell requires to synthesize protein and to replicate itself, to be short it is the storage repository for the information that is required for any cell to function. Watson-Crick has discovered the current-structure of DNA in The famous double-helix structure of DNA has its own significance. There are basically four nucleotide bases, which make up the DNA. Each base has its complementary base, which means in the double helical structure of DNA, A will have T as its complimentary and similarly G will have C. The DNA is broken down into bits and is tightly wound into coils, which are called chromosomes; human beings have 23 pairs of chromosomes.
DNA is the genetic material found in all living organisms, ranging from single-celled bacteria to multicellular mammals. It is found in the nucleus of eukaryotes and in the chloroplasts and mitochondria. In prokaryotes, the DNA is not enclosed in a membranous envelope, but rather free-floating within the cytoplasm. The entire genetic content of a cell is known as its genome and the study of genomes is genomics. In eukaryotic cells, but not in prokaryotes, DNA forms a complex with histone proteins to form chromatin, the substance of eukaryotic chromosomes. A chromosome may contain tens of thousands of genes.
Nucleic acid structure
Ribonucleic acid RNA is a polymeric molecule essential in various biological roles in coding , decoding , regulation and expression of genes. Along with lipids , proteins , and carbohydrates , nucleic acids constitute one of the four major macromolecules essential for all known forms of life. Cellular organisms use messenger RNA mRNA to convey genetic information using the nitrogenous bases of guanine , uracil , adenine , and cytosine , denoted by the letters G, U, A, and C that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome. Some RNA molecules play an active role within cells by catalyzing biological reactions, controlling gene expression , or sensing and communicating responses to cellular signals. One of these active processes is protein synthesis , a universal function in which RNA molecules direct the synthesis of proteins on ribosomes. Analysis of these RNAs has revealed that they are highly structured.
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 naturally occurring chemical compounds that serve as the primary information-carrying molecules in cells. They play an especially important role in directing protein synthesis. Nucleic acids were discovered in by Swiss biochemist Friedrich Miescher.
DNA, RNA, Protein, and Gene Expression
This page, looking at the structure of DNA, is the first in a sequence of pages leading on to how DNA replicates makes copies of itself, and then to how information stored in DNA is used to make protein molecules. This material is aimed at 16 - 18 year old chemistry students. If you are interested in this from a biological or biochemical point of view, you may find these pages a useful introduction before you get more information somewhere else.
Deoxyribonucleic acid, or DNA, is a molecule that contains the instructions an organism needs to develop, live and reproduce. These instructions are found inside every cell, and are passed down from parents to their children. DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine A , thymine T , guanine G and cytosine C.
DNA and RNA
Nucleic acid structure is often divided into four different levels: primary, secondary, tertiary, and quaternary. Primary structure consists of a linear sequence of nucleotides that are linked together by phosphodiester bond. Nucleotides consist of 3 components:. The nitrogen bases adenine and guanine are purine in structure and form a glycosidic bond between their 9 nitrogen and the 1' -OH group of the deoxyribose. Cytosine, thymine, and uracil are pyrimidines , hence the glycosidic bonds form between their 1 nitrogen and the 1' -OH of the deoxyribose. For both the purine and pyrimidine bases, the phosphate group forms a bond with the deoxyribose sugar through an ester bond between one of its negatively charged oxygen groups and the 5' -OH of the sugar. Nucleic acids are formed when nucleotides come together through phosphodiester linkages between the 5' and 3' carbon atoms.
Танкадо снова протянул руку. Пожилой человек отстранился. Танкадо посмотрел на женщину, поднеся исковерканные пальцы прямо к ее лицу, как бы умоляя понять. Кольцо снова блеснуло на солнце. Женщина отвернулась. Танкадо, задыхаясь и не в силах произнести ни звука, в последней отчаянной надежде посмотрел на тучного господина.
Quien es. Кто он. - Понятия не имею. - Похож на китайца. Японец, подумал Беккер. - Бедняга. Сердечный приступ.
Какие же страшные были у него руки. - Вот тут-то вы и рассмотрели его кольцо. Глаза Клушара расширились. - Так полицейский сказал вам, что это я взял кольцо. Беккер смущенно подвинулся.
Era un punqui, - ответила Росио. Беккер изумился. - Un punqui. - Si. Punqui.
- Но будем надеяться, что он этого не узнает. ГЛАВА 76 У подъезда севильского аэропорта стояло такси с работающим на холостом ходу двигателем и включенным счетчиком. Пассажир в очках в тонкой металлической оправе, вглядевшись сквозь стеклянную стену аэровокзала, понял, что прибыл вовремя. Он увидел светловолосую девушку, помогающую Дэвиду Беккеру найти стул и сесть.