The backbone of a nucleic acid molecule is made of the sugar and phosphate lying on the outside of the helix. The phosphate residue is attached to the hydroxyl group of the 5′ carbon of one sugar and the hydroxyl group of the 3′ carbon of the sugar of the next nucleotide, which forms a 5′–3′ phosphodiester linkage.ĭouble-Helix structure of nucleic acids - DNA The carbon atoms of the sugar molecule are numbered as 1′, 2′, 3′, 4′, and 5′ (1′ is read as “one prime”). The difference between the sugars is the presence of the hydroxyl group on the second carbon of the ribose and hydrogen on the second carbon of the deoxyribose. The pentose sugar in DNA is deoxyribose, and in RNA, the sugar is ribose. The primary structure of a purine is two carbon-nitrogen rings.Ĭytosine, thymine, and uracil are classified as pyrimidines which have a single carbon-nitrogen ring as their primary structure. Nucleotides of RNA contain uracil (U) instead of thymine.Īdenine and guanine are classified as purines. The nucleotides combine with each other to form a polynucleotide.īasic building blocks of nucleic acids are three different components:Įach nitrogenous base in a nucleotide is attached to a sugar molecule, which is attached to one or more phosphate groups.Įach nucleotide in DNA contains one of four possible nitrogenous bases: Nucleic acids are made up of monomers called nucleotides. Three parts of a nucleotide – a building block of nucleic acids (DNA and RNA) Adds short peptide tags to proteins to facilitate the degradation of incorectly synthesized proteins. Involved in the selection of proteins for export. Plays a key role in the processing of rRNA molecules. Provides structural framework for ribosomes. Transfers amino acid to mRNA for protein biosynthesis. Serves as precursor for mRNA and other RNAs. Transfers genetic information from genes to ribosomes to synthesize proteins. There are four major types of ribonucleic acid: messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), and microRNA (miRNA).įunctions and types of ribonucleic acid (RNA) Type of RNA It employs methods of molecular biology and genetics. Such field of biology as molecular genetics studies the structure and function of genes, how genes control the development and function of organisms. Ribonucleic acid (RNA) transfers gene information from DNA to create functional products. The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).ĭeoxyribonucleic acid, known as DNA, stores hereditary information in small segments called genes inside long polymer strands. Nucleic acids use their stored genetic information to guide the synthesis of new proteins within the cell. The main function of nucleic acids is to store and transfer the genetic blueprint of all living organisms. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.Biological functions of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)Ģ types of nucleic acids are the most important macromolecules for the continuity of life. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. 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.Īn important property of DNA is that it can replicate, or make copies of itself. Nucleotides are arranged in two long strands that form a spiral called a double helix. Together, a base, sugar, and phosphate are called a nucleotide. Each base is also attached to a sugar molecule and a phosphate molecule. 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.ĭNA bases pair up with each other, A with T and C with G, to form units called base pairs. Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Mitochondria are structures within cells that convert the energy from food into a form that cells can use. 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). Nearly every cell in a person’s body has the same DNA. DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms.
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