Chapter 27
prokaryotic
Gram stain
the Laguna Salada de Torrevieja (Salty Lagoon)
:is in spain
appears pink.. the pink color is caused by archaea and bacteria
click to edit
the pink color comes from trillions of prokaryotes in the domains Archaea and Bacteria. Halobacterium is one of them.
Halobacterium have red pigments and can leave among the most salt- tolerant places.
Prokaryotic species can live in extreme and normal conditions.
their are 3 most common shaapes of prokaryotes which are the...
Bacilli (singular, bacillus) are rod-shaped.
Cocci (singular, coccus) are spherical.
Spiral prokaryotes include spirilla
click to edit
developed in 19th-century Danish physician Hans Christian Gram
Gram staining is a valuable tool in medicine for quickly determining if a patient’s infection is due to gram-negative or to gram-positive bacteria.
"scientists can categorize many bacterial species according to differences in cell wall composition. To do this, samples are first stained with crystal violet dye and iodine, then rinsed in alcohol, and finally stained with a red dye such as safranin that enters the cell and binds to its DNA. The structure of a bacterium’s cell wall determines the staining response" pg. 572
capsule
is the celll wall tat is surrounded by a sticky layer of polysaccharide or protein.
endospores
produces a copy of its chromosome and surrounds that copy with a multilayered structure, forming the endospore.
fimbriae
fasten itself to the mucous membranes of its host.
Gram- positive
Gram- negative
walls composed of a thick layer of peptidoglycan
have less peptidoglycan and are structurally more complex, with an outer membrane that contains lipopolysaccharides (carbohydrates bonded to lipids
Bacteria
Archaea
a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some that can cause disease
constitute a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes.