ch 6 pt 2 Flashcards
how do u grow bacteria
Enrichment cultures and Metagenomics ( aka environmental sequencing)
How biologists study Bacteria and Archaea
1st step is to grow bacteria that you are studying.
what are enrichemnet cultures
- establish a specified set of growing conditions ( nutrients, temperature, lighting, substrate, food, etc)Important to duplicate conditions under which organisms live in
what are metagenomics
Documents phylogenetic species that cannot be grown in culture
Doing this by finding all the genes present in a community of prokaryotes, including unknown sequences
based on DNA sequences of specific genes
more is known abt _ than _
bacteria, archaea
size of bacteria =
1 um in diameter, but vary .5-.1
what shapes can they be
coccus, bacillus, spirillium, filamentous
what is coccus
spherical - may be single, double (diplo-), chain (strepto-), cluster (staphylo-
what is bacillus
rod- shaped (single or strepto-
what is spirillum
spiral, corkscrew shaped (single only
filamentous =
(many cyanobacteria
Gram-positive bacteria have
have a plasma membrane surrounded by a thick cell wall made of
peptidoglycan (stains bluish purple
Gram-negative bacteria have
a cell wall that has two components (stains reddish pink)
(a) thin wall of peptidoglycan
(b) outer phospholipid bilaye
some have capsuls, what are capsuls
1) thick gel layer outside cell wall
(2) typical of pathogens
some form endospores what are they
survival structures that forms inside bacterial cell and incredibly tough
