2.1.7 Organelles and the Production of Proteins

• What is the main function of organelles in cells?

  Involved in the production and secretion of proteins
• What are the organelles involved in protein production and their roles?

  • Nucleus: Stores DNA, manufactures RNA
  • Nucleolus: Manufactures ribosomes
  • Ribosomes: Translate mRNA into polypeptides
  • Rough Endoplasmic Reticulum (RER): Processes polypeptides into proteins
  • Golgi Apparatus: Modifies proteins for secretion
  • Vesicles: Transport proteins to the cell surface
• What is stored in the nucleus?

  DNA
• What does the nucleolus manufacture?

  Ribosomes
• What occurs during transcription?

  An mRNA copy of DNA is produced
• What happens to mRNA after it leaves the nucleus?

  It attaches to a ribosome
• What occurs during translation?

  A chain of amino acids is produced
• What is the chain of amino acids produced during translation called?

  Polypeptide
• What is the role of the rough endoplasmic reticulum (RER)?

  Processes polypeptides to produce proteins
• What is found on the surface of the rough endoplasmic reticulum?

  Many ribosomes
• What happens to proteins in the Golgi apparatus?

  Proteins are modified and prepared for secretion
• How are proteins transported from the RER to the Golgi apparatus?

  Inside vesicles
• What process occurs when vesicles fuse with the cell surface membrane?

  Secretion of proteins by exocytosis
• What type of cells have many organelles involved in protein production?

  Hormone-producing and enzyme-producing cells
• What is the sequence of events in protein production within a cell?

  1. DNA is transcribed to mRNA in the nucleus
  2. mRNA leaves the nucleus through nuclear pores
  3. mRNA attaches to ribosomes for translation
  4. Ribosomes synthesize polypeptides in the RER
  5. Polypeptides are processed in the RER
  6. Processed proteins are sent to the Golgi apparatus in vesicles
  7. Golgi apparatus modifies proteins and sends them in vesicles
  8. Vesicles fuse with the plasma membrane to secrete proteins