Protein Synthesis

• When does transcription occur?

  Protein synthesis
• Why Transcription occurs:

  To transport code form DNA to ribosome to create proteins
• How transcription occurs (steps 1 - 3):

  1. Double helix unwinds
  2. DNA unzips/weak hydrogen bonds break into TWO SEPERATE strands
  3. ONE strand acts as a template
• How transcription occurs (steps 3 - 6):

  1. Free floating RNA nucleotides from nucleoplasm
  2. join to their COMPLEMENTARY DNA base triplets OR A-U and G-C
  3. This produces mRNA
• How transcription occurs (steps 6 -9):

  1. mRNA now has the coded message for protein synthesis
  2. moves from nucleus to cytoplasm
  3. attaches to ribosome
• How many strands act as a template in transcription?

  One
• Where does translation occur? Ribosome in Cytoplasm
• Why Translation occurs:

  To translate the mRNA into a functional set of amino acids joined by peptide binds forming a protein.
• How Translation occurs (steps 1 - 3)

  1. mRNA inserts itself into the ribosome
  2. the ribosome reads 3 letters at a time called a CODON
  3. this codon matches with the ANTICODON found on the tRNA

  
• How translation occurs (steps 5 - 7):

  • the tRNA delivers the amino acid
  • these amino acids form a PEPTIDE BOND between each other
  • to form the require PROTEIN

  
• Label this image

  A) Codon

  B) Anticodon

  
• Label this image

  A) Amino Acid

  B) Anticodon

  
• Name THREE reasons why DNA replication needs to occur.

  
  

  1. maintains chromosome number
  2. allows for genetics to be passed on
  3. repairs/replaces damaged DNA
• Where is a codon found?: On mRNA
• The tRNA molecule carries the corresponding amino acid.
• RNA synthesis uses RNA nucleotides
• How translation occurs (steps 4-6)

  4. the amino acid attached to tRNA is left at ribosome

  5. forms a peptide bond with next amino acid

  6. tRNA goes off to collect another amino acid which matches its anticodon