Nucleotides and Nucleic acids

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Nucleotides and Nucleic acids
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• Some basics about DNA and RNA
• DNA is a polynucleotides having a specific
  sequence of deoxyribonucleotide units covalently
  joined through 3, 5-phosphodiester bonds
• RNA is a polyribonucleotide of specific sequence
  linked by successive 3, 5-phosphodiester bonds
• DNA (double stranded) and RNA (single stranded)
  are long linear polymers, called nucleic acids
  that carry information in a form that can pass
  from one generation to the next
• These macromolecules consist of a large number of
  linked nucleotides , each composed of sugar , a
  phosphate, and a base
• Sugars linked by phosphates form a common back
  bone but the base varies among four kinds

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N-ß-glycosyl bond
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• Genetic information are stored in the sequence of
  base along a nucleic acid chain
• Bases are paired by hydrogen bond these base
  pairing results in a double helix (helical
  structure consisting of two strands)
• A segment of DNA molecule that contains the
  information required for the synthesis of a
  protein or RNA is referred to as gene
• The only function of DNA is the storage and
  transmission of biological information
• One of the functions of RNA is the biosynthesis
  of proteins

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• RNA have broad rang of functions and several
  classes are found in the cell
• Messenger RNAs (mRNAs) are intermediaries,
  carrying genetic information from one or few
  genes t a ribosome, where the corresponding
  protein can be synthesized
• Transfer RNAs (tRNAs) are adapter molecules that
  translate the information in mRNA into a specific
  sequence of amino acids ( bring amino acids to
  the translation machinery)
• Ribosomal RNA (rRNAs) are components of the
  ribosomes (the complexes that carry out the
  synthesis of protein). are structural components
  of the ribosome and are needed for translation.
  rRNA eukaryotic cell. In the cytoplasm, rRNA and
  protein combine to form a protein called a
  ribosome. The ribosome binds mRNA and carries out
  protein synthesis. Several ribosomes may be
  attached to a single mRNA at any time.
• snRNA (small nuclear RNA) aid in DNA splicing in
  the
• nucleus and help with chromosome
  maintenance

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• Nucleotides and nucleosides
• Nucleotides have 3 components A nitrogenous
  base, pentose and phosphate
• The molecule without phosphate group is called
  nucleoside
• The carbon and nitrogen are numbered, The pentose
  ring are numbered, but the pentose nucleotides
  and nucleosides the carbon numbers are given a
  prime() designation to distinguish them from the
  numbered atoms of the nitrogen base

Deoxyribonucleotide
Ribonucleotide
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• The nitrogen base are pyrimidine and purine

DNA has AGCT RNA has AGCU