Microbiology with Diseases by Taxonomy - History and Prokaryotes

Vocabulary flashcards generated from chapters 1 and 11 of Microbiology with Diseases by Taxonomy (6th Edition).

Microbiology

The study of microscopic organisms, which are the most populous and diverse group of organisms found everywhere on the planet.

Microbes

Organisms usually smaller than $1\text{ mm}$ in diameter that are often unicellular, and if multicellular, lack differentiated tissues.

Cytoplasmic (cell) membrane

A cell barrier common to all cells that separates the inside of the cell from the outside environment.

Cytoplasm

An aqueous mixture of macromolecules, ions, and ribosomes found in all cells.

Ribosomes

Protein-synthesizing structures found in all cells.

Cell wall

A structure present in most microbes that confers structural strength.

Prokaryotes

Organisms that lack membrane-enclosed organelles and a nucleus, and are generally smaller than eukaryotic cells.

Eukaryotes

Organisms with DNA enclosed in a membrane-bound nucleus, containing organelles and generally larger and more complex than prokaryotes.

Nucleoid

The region in a prokaryotic cell where the single, circular DNA chromosome aggregates.

Plasmids

Small amounts of extrachromosomal DNA in prokaryotes that confer special properties such as antibiotic resistance.

Metabolism

The chemical transformation of nutrients within living cells.

Differentiation

The synthesis of new substances or structures that modify the cell, occurring in some microbes.

Carl Woese

Scientist who used ribosomal RNA (rRNA) comparison in the 1970s to demonstrate two distinct groups of prokaryotic organisms: Bacteria and Archaea.

Domain Bacteria

A domain of usually single-celled organisms lacking a membrane-bound nucleus, the majority of which have a cell wall containing peptidoglycan.

Cyanobacteria

A group within Domain Bacteria that produces significant amounts of oxygen.

Domain Archaea

A domain of prokaryotic organisms distinguished from Bacteria by unique rRNA gene sequences, unique membrane lipids, and an absence of peptidoglycan in their cell walls.

Algae

Photosynthetic, plant-like protists that produce approximately $75\text{\%}$ of the planet's oxygen and form the foundation of aquatic food chains.

Protozoa

Unicellular, ingestive, animal-like protists that are usually motile and act as the principal hunters and grazers of the microbial world.

Slime molds

Absorptive, fungus-like protists that behave like protozoa in one stage of their life cycle and like fungi in another stage.

Water molds

Filamentous protists that grow on the surface of freshwater and moist soil, feeding on decaying vegetation.

Saprophytes

Organisms, such as molds and mushrooms, that absorb nutrients and organic molecules from their environment for carbon and energy.

Viruses

Acellular infectious agents that require a host cell to replicate and can be much smaller than bacteria.

Viroids

Acellular infectious agents composed only of RNA that cause plant diseases.

Satellites

Acellular infectious agents composed only of RNA that cause plant and animal diseases.

Prions

Acellular infectious agents composed only of protein that cause a variety of spongiform encephalopathies.

Last universal common ancestor (LUCA)

The root of the tree of life based on rRNA, from which Bacteria and Archaea originally evolved.

Pure (axenic) culture

A culture in which microorganisms are removed from their normal habitats and grown isolated from other microbes.

Robert Hooke

Scientist credited with publishing the first drawings of microorganisms (Mucor) in scientific literature in his 1665 book Micrographia.

Antoine van Leeuwenhoek

Microscope maker ($50\text{--}300\times$) who sent letters to the Royal Society of London starting in 1673 describing observations of bacteria and protists.

Spontaneous generation

The idea that living organisms could develop or arise from nonliving matter.

Francesco Redi

Italian scientist (1626-1697) who discredited spontaneous generation for macroorganisms by showing that maggots on decaying meat came from fly eggs.

John Needham

Scientist (1713-1781) who supported spontaneous generation by showing that boiled, sealed mutton broth became cloudy and contained microorganisms.

Lazzaro Spallanzani

Scientist (1729-1799) who attacked spontaneous generation by showing that broth sealed and then boiled produced no microbial growth unless exposed to air.

Louis Pasteur

French scientist (1822-1895) who disproved spontaneous generation in 1861 using swan-necked flask experiments.