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Module 14 in the Syllabus

Bacteria and Archaea Images
Image gallery for study with links to larger teaching JPEGs for classroom presentation

Question Drill for Bacteria and Archaea
Conceptual Vocabulary Self-Test

Basic Terms Crossword Puzzle

Basic Puzzle Solution

Conceptual Vocabulary
ProkaryoteProkaryotes are a group of organisms that lack a cell nucleus or any other membrane-bound organelles.
MicroorganismA microorganism is an organism that is too small to be seen by the human eye.
BacteriaBacteria are prokaryotic unicellular microorganisms ubiquitous in every habitat on Earth.
ArchaeaThe Archaea, or archaebacteria, are a major group of prokaryotic microorganisms in which many species are extremophiles.
Cell wallA cell wall is a fairly rigid layer surrounding a cell, located external to the cell membrane.
Binary fissionBinary fission is the form of asexual reproduction in prokaryotic single-celled organisms by which one cell divides into two cells of the same size.
CocciCocci are microorganisms whose overall shape is spherical or nearly spherical.
SpirillumSpirillum in microbiology refers to a bacterium with a cell body that twists like a spiral.
FlagellumA flagellum is a long, slender projection from the cell body, composed of microtubules and surrounded by the plasma membrane.
PeptidoglycanPeptidoglycan or murein is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of eubacteria.
NucleoidThe nucleoid in prokaryotes is an irregularly shaped region within the cell where the genetic material is localized.
PilusA pilus is a hairlike appendage found on the surface of many bacteria.
AutotrophAn autotroph is an organism that produces complex organic compounds from simple inorganic molecules and an external source of energy.
Gram-positiveGram-positive bacteria are those that retain a crystal violet dye during the Gram stain process.
Petri dishA Petri dish is a shallow glass or plastic cylindrical dish that biologists use to culture cells.
Cell envelopeThe cell envelope of a bacterium is the cell membrane and cell wall plus an outer membrane.
FlagellinFlagellin is a protein that arranges itself in a hollow cylinder to form the filament in bacterial flagellum
CarboxysomeThe carboxysome is a bacterial microcompartment made up of a protein shell, that contains enzymes involved in carbon fixation reactions.
EndosporeAn endospore is a dormant, tough, non-reproductive structure produced by a small number of bacteria the purpose of which is to ensure the survival of the bacterium through periods of environmental stress.
CyanobacteriaCyanobacteria is a phylum of bacteria which obtain their energy through photosynthesis, often referred to as blue-green algae.
ExtremophileAn extremophile is an organism that thrives in and may even require physically or geochemically extreme conditions that are detrimental to the majority of life on Earth.
FimbriaA fimbria is a proteinaceous appendage in many gram-negative bacteria that is thinner and shorter than a flagellum.
ChemotaxisChemotaxis is the phenomenon in which bodily cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment.
PseudopeptidoglycanPseudopeptidoglycan or pseudomurein is a major cell wall component of some archaebacteria that chemically differs from but resembles eubacterial peptidoglycan.
S-layerAn S-layer is a part of the cell envelope commonly found in bacteria, as well as among archaea, consisting of a monomolecular layer composed of identical proteins or glycoproteins.
Nitrifying bacteriaNitrifying bacteria are chemoautotrophic bacteria that grow at the expense of inorganic nitrogen compounds.
Periplasmic spaceThe periplasmic space is the space seen between the plasma membrane and the outer membrane in the Gram-negative bacteria.
MagnetosomeMagnetosome chains are membranous prokaryotic organelles present in magnetotactic bacteria containing 15 to 20 magnetite crystals that together orient magnetotactic bacteria in geomagnetic fields.
GlycocalyxGlycocalyx is a general term referring to extracellular polymeric material produced by some bacteria, epithelia and other cells.
Teichoic acidTeichoic acids are polymers of glycerol or ribitol found in the cell wall of gram-positive bacteria appearing to extend to the surface of the peptidoglycan layer.

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