DNA: Difference between revisions
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<StructureSection load='B-DNA.pdb' size=' | <StructureSection load='B-DNA.pdb' size='340' frame='true' align='left' caption='B-DNA' scene='DNA/B-dna/7'> | ||
'''Deoxyribonucleic acid''' or '''DNA''' is a molecule which is the carrier of genetic information in nearly all the living organisms. It contains the biological instructions for the development, survival and reproduction of organisms. | '''Deoxyribonucleic acid''' or '''DNA''' is a molecule which is the carrier of genetic information in nearly all the living organisms. It contains the biological instructions for the development, survival and reproduction of organisms. | ||
DNA is found in the nucleus of a cell where it is packaged into a compact form called a chromosome with the help of several proteins known as histones. It is also found in cell structures called mitochondria. However in case of prokaryotes DNA is not enclosed in a nucleus or a membrane but is present in the cytoplasm. The DNA in prokaryotes in generally circular and supercoiled without any histones. DNA stores genetic information as a sequence of nucleotides in special regions known as genes which are used to make proteins. The expression of genetic information into proteins is a two-stage process wherein the sequence of nucleotides in DNA is converted to a molecule called Ribonucleic acid or [[RNA]] by a process called [[transcription]]. RNA is used to make proteins by another process called [[translation]]. The human genome contains nearly 3 · 10<sup>9</sup> bases with around 20,000 genes on 23 chromosomes. <ref name='gene'>http://www.genome.gov/25520880 </ref> | DNA is found in the nucleus of a cell where it is packaged into a compact form called a chromosome with the help of several proteins known as histones. It is also found in cell structures called mitochondria. However in case of prokaryotes DNA is not enclosed in a nucleus or a membrane but is present in the cytoplasm. The DNA in prokaryotes in generally circular and supercoiled without any histones. DNA stores genetic information as a sequence of nucleotides in special regions known as genes which are used to make proteins. The expression of genetic information into proteins is a two-stage process wherein the sequence of nucleotides in DNA is converted to a molecule called Ribonucleic acid or [[RNA]] by a process called [[transcription]]. RNA is used to make proteins by another process called [[translation]]. The human genome contains nearly 3 · 10<sup>9</sup> bases with around 20,000 genes on 23 chromosomes. <ref name='gene'>http://www.genome.gov/25520880 </ref> | ||