Notes

24-2 Structure of Bacteria

Peptidoglycan - A protein-carbohydrate compound found in the cell walls of eubacteria.
Methanogens - A broad phylogenetic group of archaebacteria
Extreme halophiles - Salt-loving archaebacteria
Thermoacidophiles - The third group of archaebacteria
Bacilli - Rod-shaped bacteria
Cocci - Sphere-shaped bacteria
Spirilla - Spiral-shaped bacteria
Streptococci - When cocci occur in chains
Staphylococci - grapelike clusters of cocci
Gram stain - technique used to group bacteria into categories
Gram-positive - bacteria that appear purple
Gram-negative - bacteria that appear pink **Because gram-positive bacteria have a thicker layer of peptidoglycan in their cell wall than gram-negative bacteria do, they are able to retain the gram stain**
Heterocysts - specialized cells
Population bloom/eutrophication - sudden increase in cyanobacteria
Spirochetes - gram-negative, spiral-shaped heterotrophic bacteria
Actinomycetes - gram-positive bacteria that form spiraling filaments
Antibiotics - chemicals that inhibit the growth of or kill other microscopic organisms
Enteric bacteria - gram-negative heterotrophic bacteria that inhabit animal intestinal tracts and can live in either aerobic or anaerobic condition
Chemoautotrophs - gram-negative bacteria that can extract energy from minerals by oxidizing the chemicals that can extract energy from minerals by oxidizing the chemicals in these minerals
Capsule - outer covering for bacteria
Glycocalyx - when a capsule consists of a fuzzy coat of sticky sugars
Pili - short, hairlike protein structures found on the surface of some species of bacteria
Endospore - dormant structure produced by gram-positive bacterial species exposed to harsh environmental conditions
Saprophytes - heterotrophic bacteria that feed on dead and decaying material
Photoautotrophs - bacteria that use sunlight as an energy source like cyanobacteria
Obligate anaerobes - cannot survive in the presence of oxygen
Facultative anaerobes - can live with or without oxygen
Obligate aerobes - bacteria that cannot survive without oxygen
Thermophilic - bacteria that grow best in temperatures between 40C and 110C
Transformation - bacterial cells take in DNA from its external environment
Conjugation - process by which two living bacterial binds together and one bacterium transfers genetic information to the other
Conjugation bridge - a passageway for the transfer of genetic information
Transduction - virus obtains a fragment of DNA from a host bacterium