4. Kingdom Monera
B
I
O
L
O
G
Y
Mr. Nattapong Boonpong (B.Ed.)
Bodindecha (Sing Singhaseni)
Prokaryotic Cells
• Comparing Prokaryotic and Eukaryotic
Cells
– Prokaryote comes from the Greek words
for prenucleus.
– Eukaryote comes from the Greek words
for true nucleus.
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5. Prokaryote Eukaryote
• One circular • Paired
chromosome, not in chromosomes, in
a membrane nuclear membrane
• No histones • Histones
• No organelles • Organelles
• Peptidoglycan cell • Polysaccharide cell
walls walls
• Binary fission • Mitotic spindle
Glycocalyx
• Outside cell wall
• Usually sticky
• A capsule is neatly
organized
• A slime layer is
unorganized & loose
• Extracellular
polysaccharide
allows cell to attach
• Capsules prevent
phagocytosis
Cell Wall
• Prevents osmotic lysis
• Made of peptidoglycan (in bacteria)
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7. Gram-Positive cell walls
• Teichoic acids:
– Lipoteichoic acid links to plasma membrane
– Wall teichoic acid links to peptidoglycan
• May regulate movement of cations
• Polysaccharides provide antigenic variation
Gram-Negative Outer Membrane
• Lipopolysaccharides, lipoproteins, phospholipids.
• Forms the periplasm between the outer membrane and
the plasma membrane.
• Protection from phagocytes, complement, antibiotics.
• O polysaccharide antigen, e.g., E. coli O157:H7.
• Lipid A is an endotoxin.
• Porins (proteins) form channels through membrane
Gram-Negative Outer Membrane
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8. Gram Stain Mechanism
• Crystal violet-iodine crystals form in cell
• Gram-positive
– Alcohol dehydrates peptidoglycan
– CV-I crystals do not leave
• Gram-negative
– Alcohol dissolves outer membrane and leaves holes
in peptidoglycan
– CV-I washes out
Atypical Cell Walls
• Mycoplasmas
– Lack cell walls
– Sterols in plasma membrane
• Archaea
– Wall-less, or
– Walls of pseudomurein (lack NAM and D amino acids)
Damage to Cell Walls
• Lysozyme digests disaccharide in peptidoglycan.
• Penicillin inhibits peptide bridges in peptidoglycan.
• Protoplast is a wall-less cell.
• Spheroplast is a wall-less Gram-positive cell.
• L forms are wall-less cells that swell into irregular
shapes.
• Protoplasts and spheroplasts are susceptible to
osmotic lysis.
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9. Fimbriae & Pili
• Fimbriae allow
attachment
• Pili are used to
transfer DNA from
one cell to another
Fimbriae
200 nm
Flagella
• Outside cell wall
• Made of chains of
flagellin
• Attached to a protein
hook
• Anchored to the wall
and membrane by
the basal body
Flagella Arrangement
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10. Motile Cells
• Rotate flagella to run or tumble
• Move toward or away from stimuli (taxis)
• Flagella proteins are H antigens
(e.g., E. coli O157:H7)
Motile Cells
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11. Plasma Membrane
Plasma Membrane
• Phospholipid bilayer
• Peripheral proteins
• Integral proteins
• Transmembrane proteins
Fluid Mosaic Model
• Membrane is as viscous as olive oil.
• Proteins move to function
• Phospholipids rotate and move
laterally
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12. • Some prokaryotes
– Do have specialized membranes that perform
metabolic functions
0.2 m 1 m
Respiratory
membrane
Thylakoid
membranes
(a) Aerobic prokaryote (b) Photosynthetic prokaryote
Nucleoid
• The typical prokaryotic genome
– Is a ring of DNA that is not surrounded by a
membrane and that is located in a nucleoid region
• Some species of bacteria
– Also have smaller rings of DNA called plasmids
Chromosome
1 m
Endospores
• Resting cells
• Resistant to desiccation, heat, chemicals
• Bacillus, Clostridium
• Sporulation: Endospore formation
• Germination: Return to vegetative state
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13. Endospores
Endospore
0.3 m
Type of Bacteria: Shape
• Average size: 0.2 -1.0 µm 2 - 8 µm
• Basic shapes:
Type of Bacteria: Shape
Spheres (Coccus/Cocci)
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14. Type of Bacteria: Shape
Rods (Bacillus/Bacilli)
Type of Bacteria: Shape
Spirals (Spirillum/Spirilli)
Type of Bacteria: Nutrition and metabolic adaptation
• A great diversity of nutritional and metabolic
adaptations have evolved in prokaryotes
• Examples of all four models of nutrition are found
among prokaryotes
– Photoautotrophy
– Chemoautotrophy
– Photoheterotrophy
– Chemoheterotrophy
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15. Type of Bacteria: Nutrition and metabolic adaptation
• Major nutritional modes in prokaryotes
Type of Bacteria: Metabolic Relationships to Oxygen
• Obligate aerobes
– Require oxygen
• Facultative anaerobes
– Can survive with or without oxygen
• Obligate anaerobes
– Are poisoned by oxygen
Reproduction
• Prokaryotes reproduce quickly by binary fission
– And can divide every 20 minutes to 1–3 hours
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17. Classification: Subkingdom Archaebacteria
Euryarchaeota (Methanophile & Halophile)
Crenarchaeota (Thermophile & Acidophile)
Archaea
• Some archaea
– Live in extreme environments
• Extreme thermophiles
– Thrive in very hot environments
Archaea
• Extreme halophiles
– Live in high saline environments
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18. Archaea
• Methanogens
– Live in swamps and marshes
– Produce methane as a waste product
• Hyperthermophiles
– Pyrodictium
– Sulfolobus
• Methanogens
– Methanobacterium
• Extreme halophiles
– Halobacterium
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19. Microbial Diversity
• Bacteria size range
– Thiomargarita
(750 µm) to
nanobacteria
(0.02 µm) in
rocks
Classification: Subkingdom Archaebacteria
Crenarchaeota (Thermophile & Acidophile)
Pyrococcus abyssi (archaea)
• 3,500 m deep in the Southeast Pacific.
• Optimally at 103°C (217°F)
• 200 atms
Classification: Subkingdom Archaebacteria
Crenarchaeota (Thermophile & Acidophile)
P. furiosus (archaea)
• In the marine sand surrounding
sulfurous volcanoes.
• Optimally at 100°C (212°F)
• Highly resistant to radiation
• May possess an efficient
system for repairing DNA.
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20. Classification: Subkingdom Eubacteria
Proteobacteria
Rhizobium sp.
Classification: Subkingdom Eubacteria
Proteobacteria
Helicobacter pylori
Classification: Subkingdom Eubacteria
Clamydias
• Chlamydia trachomatis
- May be transmitted to newborn's eyes
- Painful urination and watery discharge
• Mycoplasma hominis
• Ureaplasma urealyticum
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21. Nongonococcal Urethritis
• Chlamydia trachomatis
– May be transmitted to newborn's eyes
– Painful urination and watery discharge
• Mycoplasma hominis
• Ureaplasma urealyticum
Gonorrhea
• Neisseria gonorrhoeae
• Attaches to oral or urogenital mucosa by fimbriae
• Females may be asymptomatic; males have painful
urination and pus discharge
• Treatment with antibiotics
• Untreated may result in
– Endocarditis
– Meningitis
– Arthritis
– Ophthalmia neonatorum
Gonorrhea
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22. Classification: Subkingdom Eubacteria
Spirochete
Leptospirosis
• Leptospira interrogans
• Reservoir: Dogs and
rats
• Transmitted by
skin/mucosal contact
from urine-
contaminated water
• Diagnosis: Isolating
bacteria or serological
tests
Syphilis
• Treponema pallidum
• Invades mucosa or through skin breaks
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23. Classification: Subkingdom Eubacteria
Gram-Positive Bacteria
Lactobacillus sp.
Streptomyces sp.
Bacillus sp.
Classification
I. Cyanophyta
I. Cyanophyta Blue green algae (Cyanobacteria)
Morphology
• Non nuclear membrane
• Cell wall ; Cellulose & Pectin
• Non flagella
• Cyanophycean Starch
• Pigment : chlorophyll a , B - carotene , Flavicin &
phycobilin 2 type ; c - phycoerythrin & c - phycocyanin
ทําใหมสีน้ําเงิน
ี
I. Cyanophyta
I. Cyanophyta
Habitat
• น้ําจืด น้ําเค็ม ในดินที่ชนแฉะ
ื้
• บางชนิดเปน phycoplankton พบในน้ําจืดและทะเลสาบทั่วไป
• Ex. Anabaena , Nostoc , Calothrix , Cylindrospermum , Tolypothrix
Oscillatoria etc.
การดํารงชีวิต
• Mutualism ; lichen :-
• Gloeocapsa & Nostoc is phycobionts
• Anabaena azollae & Azolla filiculoides
• Blue green algae & Protozoa พวก rhizopod ที่เรียกวา cyanellae
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