nucleic acids

• What is DNA?

  • Deoxyribonucleic acid (DNA) is an important information-carrying molecule.
  • DNA is the genetic material in all living organisms, ranging all the way from single-celled bacteria to multicellular mammals.
  • The DNA code tells the cell what to do and what proteins to make.
  • The cell's entire genetic content is called its genome and the study of genomes is genomics.
• Eukaryotic vs prokaryotic DNA

  • In eukaryotes, DNA is found mainly in the nucleus but there is also some in chloroplasts and mitochondria.
  • In prokaryotes, the DNA is not enclosed in a membranous envelope.
• What is RNA?

  • Ribonucleic acid (RNA) is similar to DNA.
  • RNA is mostly involved in synthesising (making) proteins.
  • Ribosomes are formed from RNA and proteins and are the protein builders of the cell.
• The role of mRNA

  • DNA never leaves the nucleus so uses messenger RNA (mRNA) to transfer genetic information to the rest of the cell.
  • mRNA moves out of the nucleus to transfer information to the ribosomes. The mRNA is then used to make proteins.
• Nucleic acids carry the cell's genetic code. These are the instructions for the function of the cell. Nucleic acids are important for passing on information from generation to generation.
• Components of nucleic acids

  • DNA and RNA are made of monomers called nucleotides.
  • Nucleotides join together to form polynucleotides.
  • Polynucleotides make up nucleic acids such as DNA or RNA.
• Structure of nucleotides

  • Each nucleotide is formed from a pentose sugar, a nitrogen-containing organic base and a phosphate group.
  • A condensation reaction between two nucleotides forms a phosphodiester bond.
  • These condensation reactions happen between a sugar group on one nucleotide and a phosphate group on a different nucleotide.
• DNA nucleotide

  • The components of a DNA nucleotide are:
  • A deoxyribose sugar.
  • A phosphate group.
  • An organic base - adenine (A), cytosine (C), guanine (G), thymine (T).
  • The components of an RNA nucleotide are:
  • A ribose sugar.
  • A phosphate group.
  • An organic base - adenine (A), cytosine (C), guanine (G), uracil (U).
• • Nucleotides
  • DNA
  • Deoxyribose sugar
  • Phosphate group
  • C, G, A or T
  • RNA
  • Ribose sugar
  • Phosphate group
  • C, G, A or U