Protein synthesis

• What happens during transcription?

  A gene of DNA is copied into mRNA
• What does mRNA stand for?

  Messenger RNA
• Why can't DNA leave the nucleus?

  Because DNA is too large
• What is the structure of mRNA compared to DNA?

  mRNA is shorter and single-stranded
• What base does mRNA contain instead of thymine?

  Uracil
• What enzyme initiates transcription?

  RNA polymerase
• What happens to the DNA strands during transcription?

  They separate to expose bases
• How do mRNA bases pair with DNA bases?

  They are complementary to each other
• What does the triplet or codon on mRNA code for?

  A specific amino acid
• How many different amino acids do cells use?

  Twenty different amino acids
• What is the role of tRNA in translation?

  It brings amino acids to the ribosome
• What is the anticodon on tRNA?

  A sequence complementary to mRNA codon
• What happens after the ribosome joins two amino acids?

  The ribosome moves along the mRNA
• What occurs at the end of translation?

  The amino acid chain detaches from the ribosome
• What are the key differences between DNA and mRNA?

  • DNA is double-stranded; mRNA is single-stranded
  • DNA contains thymine; mRNA contains uracil
  • mRNA is shorter than DNA
• What are the steps involved in transcription?

  1. RNA polymerase binds to DNA
  2. DNA strands separate
  3. RNA polymerase reads DNA bases
  4. mRNA strand is formed
  5. RNA polymerase detaches from DNA
• What are the steps involved in translation?

  1. mRNA binds to ribosome
  2. tRNA brings amino acids
  3. Ribosome joins amino acids
  4. Ribosome moves along mRNA
  5. Amino acid chain detaches and folds