Prokaryotic cells Flashcards
peptidoglycan
a large, net-like molecule found in all bacterial cell walls made up of many parallel polysaccharide chains with short peptide cross-linkages
capsule
a layer formed from starch, gelatin, protein or glycolipid , found around the outside of some bacteria
pili
thread-like protein structures found on the surface of some bacteria
bacteriophage
virus that attacks bacteria
flagella
many stranded helices of the contractile protein flagellin found on some bacteria; they move the bacteria by rapid rotations
mesosomes
infoldings of the cell membrane of bacteria
nucleoid
the area in a bacterium containing the single circular loop of coiled DNA
plasmids
small circular pieces of DNA that code for specific aspects of the bacterial phenotype
Gram staining
a staining technique used to distinguish types of bacteria by their cell wall
Gram-positive bacteria
bacteria that contain teichoic acid in their cell walls and stain purple/blue with Gram staining
Teichoic acid
a chemical substance found in the cell walls of Gram positive bacteria
Gram-negative bacteria
bacteria that have no teichoic acid in their cell walls; they stain red with Gram staining
cocci
spherical bacteria
bacilli
rod-shaped bacteria
sprilla
bacteria with a twisted or spiral shape
vibrios
comma-shaped bacteria
obligate aerobes
organisms that need oxygen for respiration
facultative anaerobes
organisms that use oxygen if it is available but can respire and survive without it
obligate anaeribes
organisms that can only respire in the absence of oxygen and are killed by oxygen
