File Name: nucleic acids dna and rna .zip
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.
Biochemistry pp Cite as. The study of nucleic acids began in with the isolation of a hitherto unknown phosphate-rich substance from the nuclei of white blood cells. Miescher called the isolated substance nuclein. Subsequently, nuclein was shown to be acidic in nature, and its name was changed to nucleic acid. Soon it became apparent that there were two types of nucleic acids, now called ribonucleic acid RNA and deoxyribonucleic acid DNA.
NCBI Bookshelf. Molecular Cell Biology. New York: W. Freeman; In their primary structures both are linear polymers multiple chemical units composed of monomers single chemical units , called nucleotides. Cellular RNAs range in length from less than one hundred to many thousands of nucleotides. Cellular DNA molecules can be as long as several hundred million nucleotides.
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.
By convention, sequences are usually presented from the 5' end to the 3' end. For DNA, the sense strand is used. Because nucleic acids are normally linear unbranched polymers , specifying the sequence is equivalent to defining the covalent structure of the entire molecule. For this reason, the nucleic acid sequence is also termed the primary structure. The sequence has capacity to represent information.
Nucleotides can be regarded as the building blocks for the larger nucleic acid molecules, DNA and RNA. Nucleoside di- and triphosphates. One or two additional.
Nucleic acid is an important class of macromolecules found in all cells and viruses. The functions of nucleic acids have to do with the storage and expression of genetic information. Deoxyribonucleic acid DNA encodes the information the cell needs to make proteins. A related type of nucleic acid, called ribonucleic acid RNA , comes in different molecular forms that participate in protein synthesis. So they're actually made of polymers of strings of repeating units, and the two most famous of the nucleic acids, that you've heard about, are DNA and RNA. And nucleic acids in the cell act to actually store information. The cell encodes information, much like you recorded on a tape, into nucleic acids.
Беккер принадлежал к миру людей, носивших университетские свитера и консервативные стрижки, - он просто не мог представить себе образ, который нарисовала Росио. - Попробуйте припомнить что-нибудь. Росио задумалась. - Нет, больше. В этот момент кровать громко заскрипела: клиент Росио попытался переменить позу. Беккер повернулся к нему и заговорил на беглом немецком: - Noch etwas. Что-нибудь .
Your email address will not be published. Required fields are marked *