Download Morphology of Prokaryotic Cells

Morphology of Procaryotic Cells
I
Characteristic of procaryotes tha t differ from euca ryotic cells.
A
1. Do not ha ve nu cleus , mito chon dria, E .R. etc ..
B
C
D
E
F
G
1. Do not have microtubules or cytoskeleton
H
II
Shapes an d arrangem ent of bacteria cells.
A
there are 3 ty pical shape s that bacteria are found in
1. Coccus (cocci = berries, spherical shape)
2. Bacillus (bacilli = little staffs, rod shape)
3. Spiral
B
cocc i arran gem ents
1. Single coccus
2. Diplococci
3. Streptococci
4. Tetrad
5. Sarcinae
6. Staphylococci
C
bacill i arran gem ents
1. Single bac illi
2. Diplob acilli
3. Streptobacilli
D
4. Coccobacillus
Type s of spiral bac teria
1.
2.
a.
Rigid b ody usu ally contains flag ella
b.
Flexi ble bo dy, m ove i n cor k scr ew m otion d ue to a xial fila me nt.
3.
Structure of procaryotic organisms
III Glycoc alyx/C apsule
A.
Components: sticky gelatinous polymer of polysaccharide and
protein foun d on the o utside of the c ell wall.
1. Thick , highly org anized, and solidly fixed to the cell w all it is
referred to as a capsule.
2. Thin lay er, unorga nized, loose ly held to the cell wall it is
referred to as a slime layer.
B.
Function:
1. attachment, Allows the bacteria to attach to surfaces in
its natu ral en viron me nt.
2. protect against dehydration,
3.
keep s nutr ients i n the c ell.
4. Capsu le protects pathogens from phagocytosis by cells of the
host.
5. Capsules may be a source of nutrition
IV Flagella
A.
Com pone nts:
1. Filament: composed of proteins called flagellin that form the long
hairlike structure that sticks out of the cell. (Not enclosed w/in the
plasma membrane in prokaryotes)
2. Hook: wide structure that holds the filament and turns it like a
propeller
3. Basal body anchors flagellum to the cell wall and plasma
membrane.
B.
C.
V
Function:
1. Propulsion and taxis (chemotaxis)
a. runs and tumbles
b. Receptors for attractants and repellant
Typ es of a rrang em ents
1. Monotrichous: a single flagellum at one end
2. Amphitrichous: a single flage llum at bo th ends of the cell
3. Lophotrichous: two or more flagella at one end of the pole.
4. Peritrichous: flagella all over th e cell.
Axial filaments in spirochetes
A Axial filam ent is located betwee n the outer sh eath and the cell wall.
VI Fimbriae
A Composition
1.
Fimbriae are hairlike appendages made out of pilin (shorter, and
thinner than flagella)
B function
1.
Use d for a ttachm ent an d co loniza tion of host.
VI Pili
A Composition
1.
Pili are m ade out of p ilin protein to form a single lon g shaft
connecting tw o bacteria together.
B Function
1.