Bacterial Cell Structure Flashcards
Compartmentalized with membrane-encased organelles with true nucleus and nuclear membrane
Eukaryotes
Non-compartmentalized type of cell
Prokaryotes
Many are specialized in hostile environments similar to prokaryotes in that they do not have a nuclei
Archaeobacteria
Cytoplasmic Structures of Bacteria:
N, R, CG, ES/S
Nucleoid– DNA appears as a diffuse nucleoloid without nuclear membrane
Ribosomes– FREE (70s in size)
Cytoplasmic Granules– store energy sources; produce energy if lack of resource
Endospores/Spores– resist harsh environmental conditions
Bacterial Genome is commonly: ss or ds
Double Stranded. Commonly double stranded, circular, coiled, compact, more than 1 chromosome in some
Bacterial Ribiosome size is commonly: 70s or 80s
70s in size. 2 subunits (50s & 30s)
80s is for Eukaryotes
Why are spores formed?
To resist harsh/ extreme environment
Bacterial Plasma Membrane is composed of and functions as:
Bilayered Lipoprotein.
Plasma Membrane for bacteria functions as inflow & outflow of enzymes. It serves as the site of electron transport chain for energy production.
Since bacteria has no mitochondria, enzyme systems in outer membrane of the mitochondria is found in the plasma membrane of bacteria.
Cell Envelope Structures:
PM, CW, C, CA (F,P)
Plasma Membrane– bilayered lipoprotein (NOT PHOSPHOLIPID BILAYER *not same)
Cell Wall– (g+, g-, acid fast)
Capsule– virulence factor; help evade phagocytosis
Cell Appendages– Flagella (locomotion) & Pilli (attachment & gene exchange)
What is the function and importance of capsule?
Virulence factor, Help evade Phagocytosis
Keep moisture in cells & resistant to drying. Protects Bacteria
What is the difference of Pili/ fimbriae & flagella
Pili is used for attachment & gene exchange while flagella is used for locomotion
When a bacteria is referred as “non-motile”– no flagella
Flagellar Arrangement:
Monotrichous
1 polar flagellum (==)~
Flagellar Arrangement:
Amphitrichous
(both sides) 1 flagellum at each end of cell ~(==)~
Flagellar Arrangement:
Lophotrichous
(tuft) 2 or more flagella at 1 or 2 poles of cell
(==)~~~~~
~~~~~(==)~~~~~
Flagellar Arrangement:
Peritrichous
(around) flagella distributed OVER entire cell
~~(==)~~
Principal Component of g+ cell wall
Peptidoglycan Layer
Unique to g+ cell wall
Teichoic Acid & Lipoteichoic Acid
2 Layers of g- cell wall:
IPL, OM
Inner Peptidoglycan Layer
Outer Membrane
Has a thin Peptidoglycan Layer
g-
Components of outer membrane of g- bacteria:
LPS, CP, AOSP, LA/E
Lipopolysaccharide
Core Polysaccharide
Antigenic O-specific polysaccharide
Lipid A/ endotoxin
what structure makes g+ different from g- bacteria?
Peptidoglycan layer
g+ (thick)
g- (thin)
Has a thick Peptidoglycan Layer & no outer membrane
Acid-Fast Cell Wall
When Acid fast bacteria is stained with gram stain, will it appear g- or g+?
g+
They retain carbolfuchsin & not decolorized by acid alcohol
What makes acid fast cell walls unique?
Mycolic Acid
Mycoplasma & Ureaplasma lacks…
Cell wall
Their cell membrane contains sterols
Rod-like shaped bacteria. Largest Variety
Bacilli
Spherical Shaped bacteria
Cocci
Spiral and flexible bacteria
Spirochetes
shorter than the usual bacillus and sometimes mistaken as cocci
Coccobacillus
comma shaped bacillus
vibrio
Spiral and rigid with polar flagella
Spirilla
