Bacteria and viruses

• What type of cells are bacteria?

  Prokaryotic cells
• How do bacteria compare to eukaryotic cells in terms of structure?

  Bacteria have a simpler structure
• What are the key structural features of bacteria?

  • Cell Wall
  • Cell Membrane
  • Cytoplasm
  • Ribosomes
  • Nucleoid Region
  • Plasmids
  • Flagella (optional)
  • Pili and Fimbriae (optional)
  • Capsule (optional)
  • Mesosomes (debatable)
• What is the composition of the bacterial cell wall?

  Made of peptidoglycan
• What is the function of the bacterial cell wall?

  Provides shape and structural support
• How does the cell wall protect bacteria?

  Protects against osmotic lysis
• What is located beneath the bacterial cell wall?

  The cell membrane
• What is the composition of the bacterial cell membrane?

  Composed of a phospholipid bilayer
• What is the role of the bacterial cell membrane?

  Controls entry and exit of substances
• What does the cytoplasm of bacteria contain?

  Enzymes and other molecules for metabolism
• What important process occurs in the bacterial cytoplasm?

  Glycolysis
• What type of ribosomes do bacteria have?

  Small 70S ribosomes
• What is the function of ribosomes in bacteria?

  Used for protein synthesis
• Where is the nucleoid region located in bacteria?

  Contains a single circular DNA molecule
• What is the significance of the DNA in the nucleoid region?

  Essential for controlling cell activities
• What are plasmids in bacteria?

  Small, circular extra-chromosomal DNA molecules
• What do plasmids often carry genes for?

  Antibiotic resistance or survival advantages
• What is the function of flagella in bacteria?

  Used for motility
• What are pili and fimbriae used for in bacteria?

  Attachment to surfaces or other bacteria
• What is the capsule in bacteria?

  A sticky outer layer for protection
• How does the capsule help bacteria?

  Protects against phagocytosis and aids adherence
• What are mesosomes in bacteria?

  Infoldings of the plasma membrane
• What is controversial about mesosomes?

  Their existence and function are debated
• What are viruses classified as?

  Non-cellular particles
• How do viruses replicate?

  They rely on host cells
• What are the key structural features of viruses?

  • Capsid
  • Genetic Material
  • Envelope (optional)
  • Attachment Proteins
  • Enzymes (optional)
• What is the capsid in viruses?

  A protein coat made of capsomeres
• What is the function of the capsid?

  Protects the viral genetic material
• What types of genetic material can viruses have?

  DNA or RNA
• What is the role of the viral genetic material?

  Contains instructions for viral replication
• What is an optional feature of some viruses?

  A lipid envelope
• What is the function of the lipid envelope in viruses?

  Helps the virus attach to host cells
• What are attachment proteins in viruses?

  Proteins that bind to host cell receptors
• What is the role of attachment proteins?

  Recognize and bind to specific receptors
• What enzymes might some viruses carry?

  Reverse transcriptase
• Why is reverse transcriptase important for some viruses?

  Essential for replication in the host cell
• What are the key differences between bacteria and viruses?

  • Size: Bacteria (1–10 µm), Viruses (20–300 nm)
  • Cellular Structure: Bacteria (prokaryotic), Viruses (non-cellular)
  • Genetic Material: Bacteria (always DNA), Viruses (DNA or RNA)
  • Reproduction: Bacteria (binary fission), Viruses (use host machinery)
  • Ribosomes: Bacteria (present), Viruses (absent)
  • Metabolism: Bacteria (independent), Viruses (no independent metabolism)
• What is the size range of bacteria?

  1–10 µm
• What is the size range of viruses?

  20–300 nm
• What type of cellular structure do bacteria have?

  Prokaryotic structure