RNA

• RNA

  A single stranded polymer, short and unstable, consists of a ribose sugar, a phosphate group, a base that’s either adenine, cytosine, guanine or uracil
• Types of RNA

  • rRNA
  • mRNA
  • tRNA
• rRNA

  Ribosomes are made of 60% rRNA and 40% protein
• Ribosomes

  • Made of two subunits, a large subunit (LSU) and a small subunit (SSU)
  • rRNA sequence is used for working out evolutionary relationships because they are found in all forms of life
• mRNA

  • Transfers the DNA code from the nucleus to the cytoplasm
  • Complementary to the DNA code
  • Used to determine the sequence of amino acids during protein synthesis
  • Very unstable after protein synthesis
• RNA polymerase

  Joins nucleotides to form phosphodiester bonds to make a strand
• mRNA is equal to 3-5 % of the total DNA in a cell, tRNA is 10-20 %.
• mRNA carries information from DNA in the form of codons, tRNA brings amino acids to the ribosome.
• mRNA has codons, tRNA has anticodons.
• mRNA has a linear structure, tRNA has a clover leaf structure.
• in mRNA there are no loops present, tRNA has multiple loops.
• DNA is double stranded, mRNA and tRNA are both single stranded.
• DNA is the largest, tRNA is the smallest and mRNA Is variable.
• DNA contains a deoxyribose sugar, both mRNA and tRNA contain a ribose sugar.
• DNA contains bases: A G T C, both mRNA and tRNA contain: A G U C
• DNA is stable, mRNA is unstable tRNA is more stable than mRNA and less stable than DNA.