Translation (Protein Synthesis)

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Translation (Protein Synthesis)

• RNA ? protein

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Making a protein

• Many RNAs needed
• mRNA, tRNA, rRNA

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Messenger RNA (mRNA)

• Carries coded instructions for protein synthesis
  (translation)
• From the DNA in the nucleus to the ribosome

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The genetic code

• Codons
• instructions for making a
• protein, a series of three nucleotides
• on the mRNA
• Each codon signifies
• start, stop, or an amino acid

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The genetic code
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Transfer RNA (tRNA)

• Brings amino acids to the ribosome so it can
  build proteins
• It has Anticodons
• 3 nucleotide sequence
• complementary to the mRNA
• codon

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Ribosomal RNA (rRNA)

• Makes up ribosomes

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Making a protein

• mRNA from nucleus Through cytoplasm to the
  ribosome
• mRNA start codon AUG signals beginning of protein

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Making a protein

• tRNA with the complementary anticodon carries
  amino acid (a.a.) to bind to the codon

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Making a protein

• Enzymes help form peptide bonds between amino
  acids
• This continues until a stop codon is reached
• Protein is released into the cell
• Watch
• This one too!

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Do we need new mRNA every time?

• NO
• The same mRNA may be used to make many copies of
  the same protein.

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Mutations

• Point mutation
• Change in one or a few nucleotides

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Mutations

• Substitution
• can have no effect
• Protein could not be made
• Protein made w/ wrong amino acid (nonfunctional
  protein)

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Mutations

• Insertions/deletions
• 1 or more nucleotides added or deleted
• Can result in frame shift mutations