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Nucleic Acids Online - fdds few
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NUCLEIC ACIDS
Nucleic acids are large biological molecules (macromolecules, polymers), that are crucial in all
life forms. They were discovered by Friedrich Miescher in 1869. There are two kinds of nucleic
acids: DeoxyriboNucleic Acid (DNA) and RiboNucleic Acid (RNA); both are composed of
monomeric units known as nucleotides. Each nucleotide has three components: a pentose or 5-
carbon sugar (ribose/deoxy ribose), a phosphate group, and a nitrogenous base. If the sugar is
deoxyribose, the polymer is DNA. If the sugar is ribose, the polymer is RNA. There are 5
primary nitrogenous bases in nucleic acids: adenine (A), cytosine (C), guanine (G), thymine (T),
and uracil (U).
Nucleic acids were named for their initial discovery within the nucleus, and for the presence of
phosphate groups (related to phosphoric acid). Although first discovered within the nucleus of
eukaryotic cells, nucleic acids are now known to be found in all life forms as well as some
nonliving entities, including within bacteria, archaea, mitochondria, chloroplasts, viruses and
viroids. All living cells contain both DNA and RNA (except some cells such as mature red
blood cells), while viruses contain either DNA or RNA, but usually not both.
Nucleic acids take part in encoding, transmitting and expressing genetic information—in other
words, information is conveyed through the nucleic acid sequence, or the order of nucleotides
within a DNA or RNA molecule. Strings of nucleotides strung together in a specific sequence are
the mechanism for storing and transmitting hereditary (or genetic) information via protein
synthesis.
Deoxyribonucleic Acid
Deoxyribonucleic acid (DNA) is a nucleic acid containing the genetic instructions used in the
development and functioning of all known living organisms (with the exception of RNA
viruses). The DNA segments carrying this genetic information are called genes. Likewise, other
DNA sequences have structural purposes, or are involved in regulating the use of this genetic
information. Along with RNA and proteins, DNA is one of the three major macromolecules that
are essential for all known forms of life. DNA consists of two long polymers (characteristically
as double helix) of simple units called nucleotides, with backbones made of sugars and
phosphate groups joined by ester bonds. These two strands run in opposite directions to each
other and are, therefore, anti-parallel. Attached to each sugar is one of four types of molecules
called nucleobases (informally, bases) adenine, guanine, cytosine, and thymine. It is the
sequence of these four nucleobases along the backbone that encodes information. This
information is read using the genetic code, which specifies the sequence of the amino acids
within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA
in a process called transcription. Within cells DNA is organized into long structures called
chromosomes. During cell division these chromosomes are duplicated in the process of DNA
replication, providing each cell its own complete set of chromosomes. Eukaryotic organisms
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Nucleic Acids Online - fdds few
Nursing (AMA Computer University)
, lOMoARcPSD|25973474
NUCLEIC ACIDS
Nucleic acids are large biological molecules (macromolecules, polymers), that are crucial in all
life forms. They were discovered by Friedrich Miescher in 1869. There are two kinds of nucleic
acids: DeoxyriboNucleic Acid (DNA) and RiboNucleic Acid (RNA); both are composed of
monomeric units known as nucleotides. Each nucleotide has three components: a pentose or 5-
carbon sugar (ribose/deoxy ribose), a phosphate group, and a nitrogenous base. If the sugar is
deoxyribose, the polymer is DNA. If the sugar is ribose, the polymer is RNA. There are 5
primary nitrogenous bases in nucleic acids: adenine (A), cytosine (C), guanine (G), thymine (T),
and uracil (U).
Nucleic acids were named for their initial discovery within the nucleus, and for the presence of
phosphate groups (related to phosphoric acid). Although first discovered within the nucleus of
eukaryotic cells, nucleic acids are now known to be found in all life forms as well as some
nonliving entities, including within bacteria, archaea, mitochondria, chloroplasts, viruses and
viroids. All living cells contain both DNA and RNA (except some cells such as mature red
blood cells), while viruses contain either DNA or RNA, but usually not both.
Nucleic acids take part in encoding, transmitting and expressing genetic information—in other
words, information is conveyed through the nucleic acid sequence, or the order of nucleotides
within a DNA or RNA molecule. Strings of nucleotides strung together in a specific sequence are
the mechanism for storing and transmitting hereditary (or genetic) information via protein
synthesis.
Deoxyribonucleic Acid
Deoxyribonucleic acid (DNA) is a nucleic acid containing the genetic instructions used in the
development and functioning of all known living organisms (with the exception of RNA
viruses). The DNA segments carrying this genetic information are called genes. Likewise, other
DNA sequences have structural purposes, or are involved in regulating the use of this genetic
information. Along with RNA and proteins, DNA is one of the three major macromolecules that
are essential for all known forms of life. DNA consists of two long polymers (characteristically
as double helix) of simple units called nucleotides, with backbones made of sugars and
phosphate groups joined by ester bonds. These two strands run in opposite directions to each
other and are, therefore, anti-parallel. Attached to each sugar is one of four types of molecules
called nucleobases (informally, bases) adenine, guanine, cytosine, and thymine. It is the
sequence of these four nucleobases along the backbone that encodes information. This
information is read using the genetic code, which specifies the sequence of the amino acids
within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA
in a process called transcription. Within cells DNA is organized into long structures called
chromosomes. During cell division these chromosomes are duplicated in the process of DNA
replication, providing each cell its own complete set of chromosomes. Eukaryotic organisms
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