Humans and the Microbial World & Diversity of Bacteria and Archaea

Vocabulary flashcards generated from lecture material covering introductory microbiology, key scientists, cell structure classifications, and prokaryotic diversity.

Antony van Leeuwenhoek

Scientist credited with discovering microscopic cells, specifically observing sperm cells, human blood cells, and bacteria.

Robert Hook

Scientist credited with discovering microscopic cells through observations of plant cells that make up cork.

Microbiology

The study of life too small to see with the naked eye.

Cambrian period

A millions of years long event occurring approximately $500\text{ million}$ years ago when animals started to dominate the Earth.

Spontaneous generation

The concept that living organisms could be produced from nonliving matter.

Francesco Redi

The scientist credited with first attempting to disprove spontaneous generation by showing that maggots on rotting meat came from fly eggs.

Louis Pasteur

Scientist who disproved spontaneous generation using swan-necked flask experiments and helped give rise to the theory of biogenesis.

Swan-necked flask experiments

Experiments designed by Louis Pasteur demonstrating that microbes only grew in food broth when microbes were introduced to it.

Theory of biogenesis

The scientific theory describing the production of life as coming from already existing life.

Normal microbiota

The population of bacteria on many body surfaces, represented by approximately $10\text{ trillion}$ bacterial cells.

Bacteria

Single-celled prokaryotic organisms with one chromosome, no nucleus, and cell walls composed of peptidoglycan.

Archaea

Single-celled prokaryotic organisms with one chromosome, no nucleus, cell walls made of pseudopeptidoglycan, and the ability to grow in extreme environments.

Peptidoglycan

The compound that makes up the cell wall of bacteria.

Pseudopeptidoglycan

The compound that makes up the cell wall of archaea.

Eukaryotes

Single-celled or multicellular organisms containing a nucleus, organelles, and multiple chromosomes.

Fungi

Eukaryotic microbes comprising single-celled forms called yeasts and multicellular forms called molds.

Algae

Photosynthetic eukaryotic microscopic organisms.

Protozoa

Single-celled, aquatic eukaryotic microbes.

Helminths

Multicellular parasitic eukaryotic worms.

Viruses

Non-cellular, non-living infectious agents capable of infecting all types of life on the planet.

Methanogens

A type of archaea found in soil and GI tracts of mammals that release flammable methane gas when producing energy.

Cyanobacteria

Ancient photosynthetic bacteria existing for $3\text{ billion}$ years in aquatic environments that pumped $O_2$ into the atmosphere.

Streptomyces

A genus of soil-dwelling bacteria that gives soil its earthy smell and produces many useful antibiotics.

Bioluminescent bacteria

Saltwater bacteria that produce light and maintain a mutually beneficial relationship with organisms such as the anglerfish.

Microscopic and Visual Scale Ranges

The logarithmic spectrum comparing the physical sizes of atoms, molecules, viruses, bacteria, eukaryotic cells, and animals alongside the viewing ranges of electron microscopes, light microscopes, and the human eye.

Microbial World Classification

The taxonomic tree dividing the microbial world into living Organisms (Domains Bacteria, Archaea, and Eukarya) and Acellular Infectious Agents (Viruses, Viroids, and Prions).