19.1 Bacteria Flashcards
what are the smallest and most common microorganisms
prokaryotes
prokaryotes
unicellular orginisms that lack a nucleus
what are the characteristics of prokaryotes
- shape
- chemical nature of their cell walls
- the way they move
- the way they obtain energy
what are the three differently shaped prokaryotes?
bacci -rod shaped
cocci - spiral shaped
spirilla - corkscrew shaped
which bacteria live almost everywhere?
eubacteria
which bacteria looks very similar to eubacteria?
archaebacteria
what are the DNA sequences of archaebacteria similar to?
the DNA sequences of key archaebacterial genes are more like those of eukaryotes than those of eubacteria
- archaebacteria may be the ancestors of eukaryotes
gram staining
a method used to tell apart the two different types of cell walls that are found in prokaryotes
gram-positive bacteria appear ____ when stained
violet
gram-negative bacteria appear ____ when stained
pink
how do prokaryotes move?
prokaryotes move in a variety of ways
heterotrophs
organisms that obtain energy by consuming other organisms
autotrophs
organisms that can make their own food
chemoautotroph
organisms that make organic carbon molecules from carbon dioxide using energy from chemical reactions
photoautotroph
organism that uses energy from sunlight to convert carbon dioxide and water to carbon compounds
chemoheterotroph
organism that takes in organic molecules and then breaks them down
photoheterotroph
organism that is photosynthetic but needs organic compounds as a carbon source
peptidoglycan
a carbohydrate inside the cell wall
methanogen
archaebacteria; produces methane gas and lives in swamps
flagella
whip-like structure that help bacteria move
obligate aerobes
organisms that require a constant supply of oxygen
obligate anaerobes
organims that DO NOT require oxygen
facultative anaerobes
organisms that can survive with or without oxygen
how do bacteria replicate?
bacteria go through asexual reproduction called binary fission.