Protein synthesis

• What is the process of protein synthesis primarily about?

  Making proteins from polypeptide chains
• Where does the first stage of protein synthesis occur?

  Inside the nucleus
• What is the first step of transcription?

  Copying a gene into mRNA
• What is the role of mRNA in transcription?

  It carries the genetic code from DNA
• Why can't DNA leave the nucleus?

  It is too large to fit through pores
• What is the term for the copy of a gene made during transcription?

  Pre-mRNA
• What enzyme is used to unwind the DNA double helix?

  DNA helicase
• What happens to RNA nucleotides during transcription?

  They align opposite complementary DNA bases
• What type of bonds join RNA nucleotides together?

  Phosphodiester bonds
• What must happen to pre-mRNA before it leaves the nucleus?

  It must be modified through splicing
• What are introns?

  Non-coding sequences in DNA
• What is the role of a spliceosome?

  To remove introns from pre-mRNA
• What are exons?

  Coding regions of DNA
• What is the final step of protein synthesis?

  Translation
• What happens during translation?

  A polypeptide chain is created
• What is the start codon?

  The first three bases of mRNA
• What does each tRNA molecule carry?

  A specific amino acid
• How does the ribosome function during translation?

  It holds mRNA and tRNA in place
• What is required to create a peptide bond?

  An enzyme and ATP
• What happens when the ribosome reaches a stop codon?

  Translation ends and the ribosome detaches
• What is the final product of translation?

  A polypeptide chain
• Where does the polypeptide chain go after translation?

  To the Golgi body for modifications
• What are the two main stages of protein synthesis?

  1. Transcription
  2. Translation
• What are the key differences between introns and exons?

  • Introns: Non-coding sequences, removed during splicing
  • Exons: Coding regions, retained in mRNA
• What is the significance of complementary base pairing in transcription?

  • Ensures accurate mRNA synthesis
  • Aligns RNA nucleotides with DNA bases
• How does the ribosome facilitate translation?

  • Holds mRNA and tRNA in place
  • Catalyzes peptide bond formation
• Why is ATP necessary for protein synthesis?

  • Provides energy for peptide bond formation
  • Powers the ribosome's movement along mRNA
• What is the role of the Golgi body in protein synthesis?

  • Modifies and folds polypeptide chains
  • Prepares proteins for their final functions