Transcript Microbial Cell Structure A. Features common to all cell types

A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
D. Viruses
Microbial Cell Structure
A. Features common to all cell types
B. Prokaryotic cells
1. General features
2. Prokaryotic Cell Structures
C. Eukaryotic cells
1. General Features
2. Eukaryotic Cell Structures
D. Viruses
Updated: Jan 23, 2007
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
D. Viruses
A. Features common to all cell types
1. Bounded by a plasma membrane
2. Contain cytoplasm
3. Utilize energy and raw materials through
metabolism
4. Have both DNA and RNA
5. Reproduce by cell division processes
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. Prokaryotic Cells
1. General Features
a) Have: no (or few) internal membranes
b) Many processes that are associated with
organelles in eukaryotes (e.g. Respiration,
photosynthesis) are mediated by specialized
regions of the plasma membrane in
prokaryotes
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. Prokaryotic Cells
1. General Features (cont.)
c) There is no membrane-bound nucleus in
prokaryotes. Instead the DNA is located within
a specialized region of the cytoplasm of the
cell called the nucleoid region. There is no
nuclear membrane surrounding the nucleoid.
d) Includes: the bacteria & archaea
the terms “prokaryotic cell” and “bacterial
cell” often are used interchangeably
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. Prokaryotic Cells
1. General Features (cont.)
e) Shapes & Arrangements: See shapes handout
f)
Sizes
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Typically ~ 0.1 - 20 m (with some exceptions)
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Typical coccus: ~ 1 m (e.g. Staphylococcus)
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Typical short rod: ~ 1 x 5 m (e.g. E. coli)
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Barely within the best resolution of a
good compound light microscope
B. Prokaryotic Cells
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
a) Plasma membrane
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Structure
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Phospholipid Bilayer with Associated Proteins
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Cholesterol is absent (except in the mycoplasma group)
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Hopanoids are often present
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Some archaea have plasma membranes with unusual
lipids and monolayer structures
Functions
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Maintain Cell Integrity
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Regulate Transport
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Specialized Functions in Bacteria
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
a) Plasma membrane (cont.)
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Internal membranes
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“Mesosomes”
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Respiratory and Photosynthetic folds
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
b) The cytoplasmic matrix
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Composition:
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Viscous aqueous suspension of proteins, nucleic acid,
dissolved organic compounds, mineral salts
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Network of protein fibers similar to the eukaryotic
cytoskeleton
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
c) Ribosomes
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Sites of protein synthesis
Typically several thousand ribosomes per bacterial
cell, depending on the state of its metabolic activity
Smaller than eukaryotic ribosomes
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
d) Cytoplasmic inclusions
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Glycogen Granules
Poly--hydroxybutyrate granules
Lipid droplets
Gas vacuoles
Metachromatic granules
(Phosphate crystals or volutin granules)
Sulfur Granules
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
e) Nucleoid
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Chromosomal DNA
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Typically, one chromosome per bacterial cell
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Consists of double-stranded, circular DNA
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A few recently discovered groups have >1 chromosome
per cell and linear chromosomes
Plasmid DNA
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R-Plasmids
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F-Plasmids
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls
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Gram Staining
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Method developed by Gram in 1888
Gram-positive cells stain purple
Gram-negative cells stain pink
Later, it was discovered that the major factor determining
Gram reactions is the bacterial cell wall structure
“Gram-positive” & “Gram-negative”
These terms can mean either:
Staining results, or
Types of cell wall structure
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls (cont.)
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Peptidoglycan Structure
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Composition
» A Polysaccharide
» Composed of alternating units of
N-acetylglucosamine (NAG) and
N-acetylmuramic acid (NAM)
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls (cont)
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Peptidoglycan Structure (cont)
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Peptide crosslinking between NAM units:
» Tetrapeptide or pentapeptide chains attached to NAM
may “crosslink” adjacent PG strands
» This gives PG a net-like or mesh-like structure.
Indirect crosslinking:
» Found in Gram-positive bacteria
» TP chains of adjacent PG strands are linked by
pentapeptide chains
Direct crosslinking:
» Found in both Gm + and Gm - bacteria
» TP chains are directly attached to each other
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls (cont.)
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Gram-positive Cell Wall
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Thick layer of Peptidoglycan
» 20-80 nm in thickness
» Extensively crosslinked, both with indirect & direct links
Teichoic Acids
» Polymers of glycerol or ribitol
» Inserted into the PG layer
» Sometimes attached to plasma membrane lipids
Periplasmic Space
» Space between the PG layer and the plasma membrane
» Much smaller than in gram negative bacteria -significance questioned
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls
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Gram-negative Cell Walls
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Outer Membrane
» 7 - 8 nm in thickness
» Bilayer of lipopolysaccharide and phospholipid, with outer
membrane proteins
» Lipopolysaccharide contains:
* Lipid A: A dimer of glucosamine with 6 fatty chains
* Core Polysaccharide: About 10 monosaccharide units
* O-side chain (O antigen)
» Lipid A is the bacterial endotoxin: triggers inflammatory
effects and hemorrhaging
» Outer Membrane Proteins:
Porin Protein: 3 porin molecules form a channel for
transport/diffusion
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls (cont.)
•
Gram-negative Cell Walls (cont.)
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Peptidoglycan Layer
» Thinner than gm positive
» 1 - 3 nm thick
» Less extensively crosslinked
» Anchored to outer membrane via Braun's lipoprotein
Periplasmic Space
» Fluid or gel-filled space
» Much larger in Gm negative cells: possibly 20 - 40% of cell
volume
» Periplasmic proteins:
Hydrolytic enzymes & Transport proteins
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls (cont.)
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Variations on Cell Wall Architecture
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Acid-fast Cell Walls
» Many genera in the “High GC gram-positive” bacterial
group contain mycolic acids, embedded in the
peptidoglycan
» Mycolic acids are a class of waxy, extremely
hydrophobic lipids
» Certain genera contain very large amounts of this
lipid, and are difficult to gram stain
» These genera may be identified by the “acid-fast”
staining technique
» Includes Mycobacterium and Nocardia
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
f)
Prokaryotic cell walls (cont.)
•
Variations on Cell Wall Architecture (cont.)
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Mycoplasmas
» Bacteria that are naturally have no cell walls
» Includes Mycoplasma and Ureaplasma
Archaea
» Have archaea cell walls with no peptidoglycan
» Many have cell walls containing pseudomurein, a
polysaccharide similar to peptidoglycan but
containing N-acetylglucosamine and Nacetyltalosaminuronic acid
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
g) Capsules, slime layers, and S-layers
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Species and strain specific
Structure of capsules & slime layers
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Polysaccharide or polypeptide layer outside cell wall
May be tightly or loosely bound
Detected by negative staining techniques
Structure of S-layers
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Found on surfaces of some bacteria and archaea
Protein layer on exterior of cell
Regular “floor tile” pattern
Function not clear -- Stability?
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
g) Capsules, slime layers, and S-layers (cont.)
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Functions of capsules & slime layers
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Attachment
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Resistance to desiccation
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Nutrient Storage
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Evasion of phagocytosis
e.g. in Streptococcus pneumoniae
S strain is encapsulated & virulent
R strain is non-encapsulated & non-virulent
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
h) Fimbriae and Pili
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Short, hair-like filaments of protein on certain
bacterial cells
Believed to function in attachment
In a few species, specialized pili (sex pili, encoded
by genes on the F plasmid) enable the transfer of
DNA from one cell to another (conjugation)
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
i)
Bacterial flagella and motility
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Function
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Motility
Almost all motile bacteria are motile by means of flagella
Motile vs. nonmotile bacteria
Detected by flagella staining or by motility agar
Different species have different flagella arrangements
Structure
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Filament
Composed of the protein flagellin
Hook & Rotor Assembly
Permits rotational "spinning" movement
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
i)
Bacterial flagella and motility (cont.)
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Mechanism of Motility
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“Run and Tumble” Movement
controlled by the direction of the flagellar spin
Counterclockwise spin = Straight Run
Clockwise spin = Random Tumble
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
i)
Bacterial flagella and motility (cont.)
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Chemotaxis
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Response to the concentration of chemical attractants and
repellants
As a bacterium approaches an attractant:
the lengths of the straight runs increase
As a bacterium approaches a repellant:
the lengths of the straight runs decrease
Mechanism of chemotaxis:
Stimulation of chemotactic receptors in the PM: this triggers a
“cascade” of enzymatic activity that alters the timer setting of
the flagella rotors
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
j)
Bacterial spores
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Function
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To permit the organism to survive during conditions of
desiccation, nutrient depletion, and waste buildup
Bacterial spores are NOT a reproductive structure, like
plant or fungal spores
Occurrence
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Produced by very few genera of bacteria
Major examples
Bacillus
Clostridium
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
j)
Bacterial spores (cont.)
•
Significance in Medicine & Industry
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Spores are resistant to killing
Cannot be killed by moist heat at 100°C (boiling)
Killing spores by moist heat requires heating to 120°C for
15-20 min (autoclaving or pressure cooking)
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
j)
Bacterial spores (cont.)
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Sporulation
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The process of spore formation
Governed by genetic mechanism
A copy of the bacterial chromosome is surrounded by a
thick, durable spore coat
This forms an endospore within a vegetative cell
When the vegetative cell dies and ruptures, the free spore
is released
A. Features Common to All Cell Types
B. Prokaryotic Cells
1. General Features
2. Prokaryotic Cell Structures
a. Plasma membrane
b. The cytoplasmic matrix
c. Ribosomes
d. Cytoplasmic inclusions
e. The nucleoid
f. Prokaryotic cell walls
g. Capsules, slime layers, and S-layers
h. Fimbriae and pili
i. Bacterial flagella and motility
j. Bacterial spores
C. Eukaryotic Cells
D. Viruses
B. 2. Prokaryotic Cell Structures
j)
Bacterial spores (cont.)
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Spore Germination
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When a spore encounters favorable growth conditions
The spore coat ruptures and a new vegetative cell is
formed
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
1. General Features
2. Eukaryotic cell structures
a. Nucleus
b. Ribosomes
c. Cytomembrane system
d. Mitochondria
e. Chloroplasts
f. Cytoskeleton
g. Vacuoles
h. Peroxisomes
D. Viruses
C. Eukaryotic Cells
1. General Features
a) Have: complex internal membrane system
compartmentalization
membrane-enclosed organelles
b) DNA is enclosed in a membrane-bound nucleus
c) Includes: animal & plant cells, fungi, & protists
(protozoa & algae)
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
1. General Features
2. Eukaryotic cell structures
a. Nucleus
b. Ribosomes
c. Cytomembrane system
d. Mitochondria
e. Chloroplasts
f. Cytoskeleton
g. Vacuoles
h. Peroxisomes
D. Viruses
C. 2. Eukaryotic Cell Structures
2. Eukaryotic Cell Structures
a) Nucleus
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Location of the cell’s DNA
Major processes:
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DNA replication
DNA expression (transcription)
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
1. General Features
2. Eukaryotic cell structures
a. Nucleus
b. Ribosomes
c. Cytomembrane system
d. Mitochondria
e. Chloroplasts
f. Cytoskeleton
g. Vacuoles
h. Peroxisomes
D. Viruses
C. 2. Eukaryotic Cell Structures
b) Ribosomes
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Thousands are located suspended in the cytoplasm
and attached to the rough endoplasmic reticulum
Major process:
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Protein synthesis (translation)
Ribosomes in the eukaryotic cytoplasm are larger than
prokaryotic ribosomes
Ribosomes are also found within mitochondria and
chloroplasts; the ribosomes of these organelles are
very similar in structure & size to prokaryotic
ribosomes
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
1. General Features
2. Eukaryotic cell structures
a. Nucleus
b. Ribosomes
c. Cytomembrane system
d. Mitochondria
e. Chloroplasts
f. Cytoskeleton
g. Vacuoles
h. Peroxisomes
D. Viruses
C. 2. Eukaryotic Cell Structures
c) Cytomembrane system
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Folded sacks of membranes within the cytoplasm
•
Carry out processing and export of the cell’s
proteins
•
Major components:
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Endoplasmic reticulum (rough and smooth)
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Golgi apparatus
–
Transport vesicles
–
Lysosomes
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
1. General Features
2. Eukaryotic cell structures
a. Nucleus
b. Ribosomes
c. Cytomembrane system
d. Mitochondria
e. Chloroplasts
f. Cytoskeleton
g. Vacuoles
h. Peroxisomes
D. Viruses
C. 2. Eukaryotic Cell Structures
d) Mitochondria
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Located in the cell’s cytoplasm
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Major process: cellular respiration
•
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The mitochondria oxidize nutrient molecules with the help
of oxygen
–
Some of the energy is conserved in the form of chemical
energy (energy-containing chemical compounds) that can
be used for biological processes
Evolved from bacteria by a process called
endosymbiosis
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
1. General Features
2. Eukaryotic cell structures
a. Nucleus
b. Ribosomes
c. Cytomembrane system
d. Mitochondria
e. Chloroplasts
f. Cytoskeleton
g. Vacuoles
h. Peroxisomes
D. Viruses
C. 2. Eukaryotic Cell Structures
e) Chloroplasts
•
Located in the cytoplasm of plant cells, algae cells,
and certain protozoan cells
•
Major process: photosynthesis
–
•
Using the energy from light, CO2 is converted into
carbohydrates such as glucose
Evolved from bacteria by endosymbiosis
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
1. General Features
2. Eukaryotic cell structures
a. Nucleus
b. Ribosomes
c. Cytomembrane system
d. Mitochondria
e. Chloroplasts
f. Cytoskeleton
g. Vacuoles
h. Peroxisomes
D. Viruses
C. 2. Eukaryotic Cell Structures
f)
Cytoskeleton
•
Microfilaments
•
Microtubules
•
Intermediate filaments
g) Vacuoles
h) Peroxisomes
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
D. Viruses
D. Viruses
1. Structure of a “Virus Particle”
a) Noncellular Biological Entity
b) Contains either DNA or RNA (not both)
c) Nucleic Acid is surrounded or coated by a
protein shell (capsid)
d) Some viruses possess a membrane-like
envelope surrounding the particle
A. Features Common to All Cell Types
B. Prokaryotic Cells
C. Eukaryotic Cells
D. Viruses
D. Viruses
2.
Viral Replication
a)
b)
c)
d)
No independent metabolism or replication
Replicate only inside an infected host cell
Do not replicate via a process of cell division
Replicate via a process of:
•
•
•
•
•
Attachment and Penetration
Disassembly (uncoating)
Synthesis of Viral Protein and Nucleic Acid
Reassembly of new viral particles
Release of new viral particles