Genetics

• What is splicing?


  Pre mRNA -> mRNA

  Introns removed (non-coding regions)
• What are exons?


  Coding regions of DNA
• What are promotor sequences?


  DNA sequence proteins bind to in order to initiate transcription
• What is transcription?


  • Makes single-stranded pre-mRNA
  • Made using DNA strand as template by RNA polymerase (reads DNA 3' to 5')
• What is rNTP?


  Ribonucleotide triphosphate (used to make RNA)
• What is translation?


  • Amino acid chain made using mRNA template, following codon usage
  • Made by ribosome & tRNA
• What is a peptide?


  Small amino acid chain
• What is a protein?


  Large & folded chain of amino acids
• How many amino acids exist?


  20
• Which side do new nucleotides join on DNA?

  3'
• Post-translational modifications:


  • Phosphorylation on Ser, Thr & Tyr (OH residue)
  • Glycosylation- attach glycans (sugar chains)
  • Palmitoylation- added fatty acid drives
  • Acetylation
  • Methylation
  • Disulfide bonds on Cys S atoms
  • Polyubiquitination on Lys- targets protein for degradation
• Which amino acid has a SH residue?

  Cysteine
• When do post-translational modifications take place?

  After protein made in ribosome

  Modifications happen for their function
• What does reverse transcriptase do?

  Transcribes RNA to DNA (in retrovirus)
• How does microRNA work?

  Binds to RNA to silence it

  Translation of protein blocked
• What do side chains in amino acids do?

  Determine size, polarity, pH & solubility
• What 3 things can an amino acid be?

  • nonpolar
  • polar (dissolve in water)
  • electrically charged (acidic or basic)
• What are non-polar amino acids used for?

  Make receptors in membrane (transmembrane) as hydrophobic side chain can be buried in lipid bilayer
• What does a peptide chain look like?

  5' to 3'

  N terminus to C terminus