Protein Synthesis

• What is the function of tRNA?

  To carry amino acids to ribosome
• What is the structure of mRNA?

  Linear, no anticodon
• Why is mRNA considered more unstable than tRNA?

  It has a shorter lifespan in the cell
• What does rRNA do?

  Joins with proteins to produce ribosomes
• What is semi-conservative replication?

  Each new DNA contains one parental strand
• What are the steps of transcription to form mRNA?

  1. DNA unwinds to expose bases
  2. Free mRNA nucleotides base pair with DNA
  3. RNA polymerase joins mRNA nucleotides
  4. mRNA strand is complementary to DNA
  5. mRNA leaves nucleus via nuclear pore
• What is the role of RNA polymerase in transcription?

  It joins RNA nucleotides to form pre-mRNA
• Why is splicing of pre-mRNA necessary?

  To remove non-coding introns from mRNA
• Why is the mRNA transcribed from a gene shorter than the gene itself?

  Some base pairs are introns, spliced out
• Describe the process of translation.

  1. mRNA attaches to ribosome
  2. tRNA pairs with mRNA codon
  3. Peptide bond forms between amino acids
  4. Ribosome moves to next codon
  5. Process repeats until stop codon is reached
• What is the first step in translation?

  mRNA attaches to small ribosomal subunit
• What happens when a stop codon is reached during translation?

  The ribosome leaves the mRNA
• Summarize the overall process of protein synthesis.

  1. DNA strands separate
  2. One strand used to make mRNA
  3. mRNA undergoes splicing
  4. mRNA associates with ribosome
  5. tRNA brings specific amino acids
  6. Amino acids join to form polypeptide
• What is the function of tRNA in translation?

  To bring specific amino acids
• How do codons and anticodons interact during translation?

  Anticodon on tRNA pairs with codon on mRNA
• What is the significance of peptide bonds in protein synthesis?

  They link amino acids in a polypeptide chain