prokaryotic cell structure

• Prokaryotic cells


  Cells that are much smaller, have no membrane-bound organelles, have smaller ribosomes, no nucleus, have a cell wall made of murein, and may contain plasmids, a capsule, and flagella
• Key differences between prokaryotic and eukaryotic cells

  • Smaller size
  • No membrane-bound organelles
  • Smaller ribosomes
  • No nucleus
  • Cell wall made of murein
  • May contain plasmids, capsule, and flagella
• Ribosomes


  Small structures made of proteins and rRNA that are responsible for protein synthesis
• Prokaryotic ribosomes


  • 70S ribosomes, much smaller than the 80S ribosomes found in eukaryotic cells
• Eukaryotic cells have 80S ribosomes, except for mitochondria and chloroplasts which have 70S ribosomes</b>
• Nucleus


  Membrane-bound organelle in eukaryotic cells that contains the cell's genetic material
• Prokaryotic cell nucleus


  • No nuclear envelope, circular DNA not bound to histones, loose in the cytoplasm
• Cell wall


  Rigid structure surrounding the cell membrane in some cells, provides structural support
• Eukaryotic cell walls


  • Found in plants (cellulose) and fungi (chitin)
• Prokaryotic cell walls


  • Made of glycoprotein called murein
• Plasmids


  Small loops of additional DNA found in some prokaryotic cells, often carry antibiotic resistance genes
• Capsule


  Thick, slimy layer outside the cell wall of some prokaryotic cells, protects against desiccation and hides antigens
• Flagella


  Tail-like structures that rotate and propel some prokaryotic cells
• Not all prokaryotic cells contain plasmids, capsules, or flagella