2.1.9 Prokaryotic and Eukaryotic Cells

• What types of cells are animal and plant cells?

  Eukaryotic cells
• What type of cells are bacteria?

  Prokaryotic cells
• How do prokaryotic cells compare in size to eukaryotic cells?

  Prokaryotic cells are 100-1000 times smaller
• What is a key structural difference between prokaryotic and eukaryotic cells?

  Prokaryotic cells lack membrane-bound organelles
• What is the size of ribosomes in prokaryotic cells?

  70S
• What is the genetic material structure in prokaryotic cells?

  A single circular DNA molecule free in cytoplasm
• What is contained in the cell wall of prokaryotic cells?

  Murein (a glycoprotein)
• What are plasmids in prokaryotic cells?

  Small loops of DNA separate from main DNA
• What advantage do plasmids provide to prokaryotes?

  They can carry genes for antibiotic resistance
• What is the function of a capsule in prokaryotic cells?

  Protects bacteria from drying out and immune attack
• What is a flagellum?

  A long, tail-like structure for movement
• How do flagella assist prokaryotic cells?

  They rotate to enable movement
• What are the unique structures found in prokaryotic cells and their purposes?

  • Plasmids: Small loops of DNA for gene transfer
  • Capsule: Protects from drying and immune attacks
  • Flagellum: Enables movement
• How are prokaryotic cells described in comparison to eukaryotic cells?

  They are simpler than eukaryotic cells
• What is the method of cell division in prokaryotic cells?

  Binary fission
• What type of ribosomes do eukaryotic cells have?

  80S ribosomes
• What are the main differences between prokaryotic and eukaryotic cells?

  • Prokaryotes:
  • Size: 0.5-5µm
  • Genome: Circular DNA, no proteins
  • Division: Binary fission
  • Ribosomes: 70S
  • Organelles: Few, no membrane-bound
  • Cell wall: Peptidoglycan
  • Eukaryotes:
  • Size: Up to 100µm
  • Genome: DNA with histones
  • Division: Mitosis or meiosis
  • Ribosomes: 80S
  • Organelles: Numerous, membrane-bound
  • Cell wall: Cellulose in plants, chitin in fungi
• What is the cell wall composition in prokaryotic cells?

  Peptidoglycan and murein
• Why should size not be included as a structural difference in exams?

  Size is not a structural feature
• How do metabolic processes differ between prokaryotic and eukaryotic cells?

  Differences affect reproduction and metabolism