Protein synthesis

• What are the two main steps of protein synthesis?

  Transcription and translation
• What happens during transcription?

  A gene is copied into mRNA
• What is the role of mRNA in protein synthesis?

  It carries the genetic code to ribosomes
• Where is the genetic material of a cell located?

  In the nucleus
• Why is DNA essential to life?

  It contains thousands of genes
• What do genes code for?

  A specific sequence of amino acids
• What is the function of ribosomes in protein synthesis?

  They read mRNA to produce proteins
• Why can't DNA leave the nucleus?

  Because it is too large
• What does mRNA stand for?

  Messenger RNA
• How does mRNA differ from DNA?

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

  Uracil
• What is the role of RNA polymerase in transcription?

  It binds to DNA and synthesizes mRNA
• What happens to the DNA strands during transcription?

  They separate to expose bases
• What is a template strand?

  The DNA strand used to make mRNA
• What is a codon?

  A group of three bases coding for an amino acid
• How many different amino acids do cells use?

  20 different amino acids
• What does the triplet 'agu' code for?

  The amino acid serine
• What is the role of tRNA in translation?

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

  A sequence of three bases on tRNA
• How does tRNA ensure the correct amino acid is brought to the ribosome?

  It has an anticodon complementary to mRNA
• 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 and folds
• What are the steps of transcription?

  1. RNA polymerase binds to DNA
  2. DNA strands separate
  3. RNA polymerase reads DNA bases
  4. Complementary mRNA bases are added
  5. mRNA strand is formed and detaches
• What are the steps of translation?

  1. mRNA binds to ribosome
  2. tRNA brings amino acids
  3. Ribosome joins amino acids together
  4. Ribosome moves along mRNA
  5. Process repeats until protein is formed
• What are the key differences between DNA and mRNA?

  • DNA is double-stranded; mRNA is single-stranded
  • DNA contains thymine; mRNA contains uracil
  • DNA is longer; mRNA is shorter