infectious organisms

• What is a microbe?

  An organism too small to see without a microscope
• What bacteria is associated with caries?

  Streptococcus mutans
• What bacteria is associated with periodontal disease?

  Porphyromonas gingivalis
• What defines a eukaryotic cell?

  Contains membrane-bound nucleus and organelles
• What is the domain of eukaryotic cells?

  Eukarya
• Name two membrane-bound organelles in eukaryotic cells.

  Mitochondria and endoplasmic reticulum
• How is the cell structure of eukaryotic cells organized?

  Organized by the cytoskeleton
• What type of DNA do eukaryotic cells have?

  Linear DNA molecules called chromosomes
• How much larger are eukaryotic cells compared to bacteria?

  10-50 times larger
• What characterizes a prokaryotic cell?

  No membrane-bound nucleus
• What are the two domains of prokaryotic cells?

  Bacteria and archaea
• Do prokaryotic cells have membrane-bound organelles?

  No, they do not
• What encloses prokaryotic cells?

  Cell wall
• What is the nucleoid in prokaryotic cells?

  Composed of supercoiled DNA and proteins
• How many chromosomes do prokaryotic cells typically have?

  One large circular chromosome
• What are plasmids in prokaryotic cells?

  Smaller circular DNA molecules
• What are surface appendages in prokaryotic cells?

  Pilus and fimbrae
• What does the morphology of prokaryotic cells depend on?

  Shape of the cell wall
• What shape is a coccus?

  Spherical
• What shape is a bacillus?

  Rod-shaped
• What shape is a vibrio?

  Curved
• What are the main aspects of bacterial taxonomy?

  • Classification
  • Description
  • Identification
  • Naming
• What is a binomial name in taxonomy?

  Only the genus is capitalized
• What is the purpose of gram staining?

  Classifies bacteria using crystal violet and iodine or safranin
• What color do gram-negative bacteria stain?

  Pink
• What characterizes gram-negative bacteria?

  Double-lipid membrane with thin wall
• What color do gram-positive bacteria stain?

  Purple
• Why do gram-positive bacteria appear purple?

  Crystal violet is trapped in thick cell wall
• What does the bacterial cell envelope consist of?

  • Plasma membrane
  • Cell wall
  • Outer membrane
  • Capsule
• What are the criteria for classifying bacteria?

  • Phenotypes: shape, metabolism, respiration
  • Gram staining: cell wall characteristics
  • Genotype: taxonomy
• What is a virus?

  An acellular pathogen with an intracellular lifestyle
• What does a virus's genome consist of?

  DNA or RNA enclosed in a protein capsid
• Why do viruses require host cells?

  To reproduce using host cell machinery
• How are viruses characterized?

  By symmetry and presence of envelope
• What are the components used to classify viruses?

  Nucleic acid composition and number of strands
• What is an infection?

  Successful colonization of a host by a microorganism
• What are the types of pathogens?

  • Cellular: bacteria, protists, fungi
  • Acellular: viruses, viroids, prions
• What is a pathogen?

  A microorganism causing disease
• What is a virulence factor?

  Genetically encoded factor aiding infection
• What is one function of toxins in pathogens?

  To reproduce and cause disease