Nucleic Acids

• Are DNA and RNA.
• Nucleic acids are macromolecules that store information and provide the instructions for building proteins.
• Chromosomes are one or more very long fibers where the DNA resides in the cell.
• A gene is a unit of inheritance encoded in a specific stretch of DNA that programs the amino acid sequence of a polypeptide.
• This interaction of DNA, RNA, and proteins enables the transmission of hereditary information from one generation to the next, ensuring the continuity of life.
• Nucleotides are monomers and they form Nucleic Acid polymers.
• Each nucleotide contains three parts:

  • At the center is a five-carbon sugar.
  • Attached to the sugar is a negatively charged phosphate group.
  • Also attached to the sugar is a nitrogenous base made of one or two rings.
  • The sugar and phosphate are the same in all nucleotides; only the base varies between one of four possible nitrogenous bases:
  • Adenine (A)
  • Guanine (G)
  • Cytosine (C)
  • Thymine (T).
• Polynucleotides is the resulting where dehydration reactions link nucleotide monomers into long chains.
• In a polynucleotide, nucleotides are joined by covalent bonds between the sugar of one nucleotide and the phosphate of the next. This results in a sugar-phosphate backbone, a repeating pattern of sugar-phosphate-sugar-phosphate.
• One long polynucleotide may contain many genes.
• Two polynucleotide strands coiled around each other to form a double helix.
• These 2 polynucleotides to strands have a hydrogen-bond, which is individually weak, but together is very stable double helix formation.
• This base pairing is specific: The base A can pair only with T, and G can pair only with C.
• • Similarities and Differences between DNA and RNA
  • Similarities:
  • Both are polymers of nucleotides.
  • They’re made of nucleotides consisting of a sugar, a phosphate, and a base.
  • Differences:
  • As its name denotes, the sugar in RNA is ribose rather than deoxyribose.
  • Instead of the base thymine, RNA has a similar but distinct base called uracil.
  • RNA is usually found in living cells in single-stranded form, whereas DNA usually exists as a double helix.