The Prokaryotic Cell Flashcards
origins of prokaryotic cells
3.8 billion years ago
microbiologic groups
bacteria (bacteriology)
fungi (mycology)
parasites (parasitology)
viruses (virology)
prokaryotes
prokaryote traits
unicellular
lack a membrane-bound nucleus
lack membrane-bound organelles
simpler genetic makeup
size
0.2 micrometers to 750 micrometers
most are between 0.5 and 2.0
micrometer
1 x 10^-6 meter
size, shape, and arrangement linked to
survival
two shapes
coccus (sphere)
bacillus (rod)
coccus shapes
single
diplo
strep (chain)
staph (cluster)
bacillus shapes
single
diplo
strep (chain)
palisades
other shapes
vibrio
coccobacillus
spiral
spirochete
stella
filamentous
pleomorphic
reproduction via
binary fission
binary fission
asexual reproduction
plasma membrane
phospholipid bilayer
hydrophilic head
hydrophobic tail
selectively permeable
cell wall
peptidoglycan layer
provides structure and shape
NAG and NAM
peptidoglycan
rigid, net-like lattice comprised of sugars and amino acids (peptides)
gram stain technique
allows classification of bacteria based on cell wall structure
gram-negative bacteria
stains pink
two membrane layers
gram-positive bacteria
stains purple
one membrane layer
acid fast stain
detects cell walls that contain a waxy lipid called mycolic acid
mycolic acid
extra rigid and tough layer of protection
reasons for transport in a cell
obtain nutrients
maintain water balance
exchange gases
dispose of waste products
passive transport
no energy required
active transport
requires energy
moves against concentration gradient
types of diffusion (passive transport)
simple diffusion
facilitated diffusion
osmosis
net movement of water across a selective membrane
water is attracted to solutes
solute
dissolved substances
isotonic environment
solute concentration is equal in and out of cell
hypertonic environment
higher solute content outside of cell
leads to plasmolysis
plasmolysis
plasma membrane shrinks away from cell wall
hypotonic environment
lower solute content outside of cell
leads to lysis
lysis
cell bursting
primary active transport
fully against concentration gradient
secondary active transport
process that wants to happen fuels process that doesn’t want to happen
phosphotransferase active transport
gets sugars into cell
flagella
filament-like extracellular structure used for motility
motility
mobility
chemotaxis
movement in response to chemical stimulus
phototaxis
response to light
aerotaxis
response to atmospheric conditions
monotrichous flagellum
one flagellum
lophotrichous flagella
2 localized
amphitrichous flagella
both ends
peritrichous flagella
everywhere
fimbriae
short, bristle-like structures used for attachment to surfaces
pili
hair-like appendage, comprised of protein piling, found on surface of many bacteria
pili uses
attachment
gliding
conjugation
conjugation
exchange of genetic info laterally
glycocalyx
viscous, gummy layer surrounding entire bacterial species
typically polysaccharides
slime layer
loose coating that does not exclude small particles
capsule
tight coating that does exclude small particles
glycocalyx functions
protection from environment
protection from immune system
attachment to surfaces
cytoplasm
gelatinous solution comprised of mainly water
nucleoid
somewhat centralized region housing bacterial genome
typically single circular DNA chromosome
ribosomes
organelles made of RNA and protein
30S + 50S = 70S
what gives structure/support
protein filaments
plasmids
circular, extrachromosomal DNA
main classes of plasmids
fertility F-plasmids
resistance plasmids
col plasmids
degradative plasmids
virulence plasmids
resistance plasmids
survive antibiotics
virulence plasmids
makes bacteria toxic
why are plasmids important to microbiological research
cloning
expression
inclusion bodies
amorphous particles in cytoplasm used as a nutrient reserve
endospores
metabolically inactive structures
highly resistant to environmental stress
can germinate back into vegetative (active) cells
what type of bacteria is most likely to form endospores
gram-positive
