Microbiology Basics Quiz

Definitions

• Microbiology: The study of microorganisms, including bacteria, viruses, fungi, and protozoa.
• Microorganism: Tiny life forms, including bacteria, that can only be seen under a microscope.
• Pathogen: A microorganism that can cause disease.
• Infectious disease: An illness caused by pathogens.

Prokaryotes and Eukaryotes

• Both groups store hereditary information in DNA
  • Prokaryotes have a single circular chromosome.
  • Eukaryotes possess multiple linear chromosomes.
• Cell membranes composed of proteins and lipids are present in both types.
• Ribosomes participate in protein synthesis:
  • Smaller ribosomes in prokaryotes.
  • Prokaryotic ribosomes are free in the cytosol.

Bacterial Overview

• Bacteria represent the smallest living cells, ranging from 0.1 to 10 µm.
• "Bacteria" is the plural of the Latin word "bacterium."

Naming of Bacteria

• Binomial nomenclature is a formal naming system comprising two Latinized parts:
  • The first part denotes the genus.
  • The second part specifies the species within that genus.
• Example: Staphylococcus aureus:
  • Genus: Staphylococcus
  • Species: aureus
  • Abbreviated as S. aureus, with related terms including Staphylococci (group name) and Staphylococcus sp. (unspecified species).

Diseases Caused by Bacteria

• Diphtheria: Caused by Corynebacterium diphtheriae.
• Whooping cough: Caused by Bordetella pertussis.
• Tetanus: Caused by Clostridium tetani.
• Notable unusual bacteria include Rickettsiae, Chlamydiae, Mycoplasma, and Cyanobacteria.

Protozoa

• Protozoa are single-celled eukaryotic organisms lacking a cell wall.
• Typically inhabit the digestive tracts of animals and feed on cellulose-rich materials.
• Movement methods include:
  • One or more flagella
  • Cilia
  • Pseudopodia (cytoplasmic extensions).
• Most protozoa are harmless, but some species cause diseases such as malaria, sleeping sickness, giardiasis, and amoebic dysentery.

Fungi

• Fungi are eukaryotic organisms characterized by a cell wall containing chitin.
• Types of fungi include:
  • Yeasts, e.g., Candida species, associated with oral thrush.
  • Molds, e.g., Aspergillus species.