protein synthesis

• what happens before protein synthesis takes place?

  • Nucleus - genetic material - form of DNA - thousands of genes
  • small sections of DNA has specific sequence of bases to code for a specific sequence of amino acids to form a particular protein
  • specific sequences of bases must be read by ribosomes outside of nucleus
  • DNA too large can't leave nucleus - copied small enough to leave nucleus - mRNA
• what is the differences with DNA and mRNA?

  • mRNA is much shorter than DNA
  • mRNA has one strand compared to DNA with two strands
  • mRNA uses uracil as a base instead of thymine
• what is transcription in protein synthesis?

  • RNA polymerase binds in front of gene
  • 2 strands of DNA separate - all bases exposed
  • RNA polymerase moves along each DNA strand - reading each base one by one to change to mRNA strand
  • RNA Polymerase detaches and DNA closes back up - free to leave nucleus
• what is translation in protein synthesis?

  • each group has 3 bases (codon) - codes for a specific amino acid
  • mRNA and ribosomes bind together - add one amino acid at a time
  • Amino acid brought to ribosome by tRNA - amino acid at the top and 3 bases complimentary to mRNA at the bottom
  • tRNA correctly brings down the complimentary bases to the ribosome and the ribosome makes a chain of amino acids
  • these fold up and form a protein