what’s in a cell?faculty.mtsac.edu/cbriggs/micr-22 cell anatomy.pdf · 2018. 2. 27. · cell wall...
TRANSCRIPT
What’s in a Cell?
From Ch. 4
Plant cell walls
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Figure 4.1 Arrangements of cocci.
.
Plane of division
Diplococci
Streptococci
Tetrad
Sarcinae
Staphylococci
Figure 4.2 Bacilli.
Single bacillus
Coccobacillus
Streptobacilli
Diplobacilli
Figure 4.3 A double-stranded helix formed by Bacillus subtilis.
Figure 4.4 Spiral bacteria.
Vibrio
Spirochete
Spirillum
Figure 4.5 Star-shaped and rectangular prokaryotes.
Star-shaped bacteria Rectangular bacteria
Figure 4.7 Arrangements of bacterial flagella.
Peritrichous Monotrichous and polar
Lophotrichous and polar Amphitrichous and polar
Figure 4.8 The structure of a prokaryotic flagellum.
Gram- negative
Cytoplasm Plasma membrane
Gram- positive
Cytoplasm
Figure 4.13a Bacterial cell walls.
Tetrapeptide side chain
Peptide cross-bridge
Carbohydrate “backbone”
Peptide bond
N-acetylmuramic acid (NAM) Side-chain amino acid Cross-bridge amino acid
NAM
N-acetylglucosamine (NAG)
Structure of peptidoglycan in gram-positive bacteria
.
Figure 4.13b Bacterial cell walls.
Protein
Plasma membrane
Cell wall Lipoteichoic acid
Peptidoglycan
Gram-positive cell wall Lipid A
Core polysaccharide O polysaccharide
Wall teichoic acid
Figure 4.13c Bacterial cell walls.
Gram-negative cell wall
Lipopolysaccharide
Outer membrane Peptidoglycan
Plasma membrane
Cell wall
Lipid A Porin protein
Phospholipid
Lipoprotein
Periplasm Protein
Lipid A
Core polysaccharide O polysaccharide
Parts of the LPS
Core polysaccharide
O polysaccharide
Figure 4.13 Bacterial cell walls.
Tetrapeptide side chain Peptide cross-bridge
Carbohydrate “backbone”
Protein
Plasma membrane
Cell wall
Wall teichoic acid
Lipoteichoic acid
Peptidoglycan
Gram-negative cell wall
Gram-positive cell wall
Lipopolysaccharide
Outer membrane Peptidoglycan
Plasma membrane
Cell wall
O polysaccharide Co r e p ol y s a c ch a r i d e
Lipid A
Porin protein
Phospholipid
Lipoprotein
Periplasm Protein
Lipid A Core polysaccharide O polysaccharide
Peptide bond
Pa rts of the L P S
N-acetylmuramic acid (NAM) Side-chain amino acid Cross-bridge amino acid
NAM
N-acetylglucosamine (NAG)
Structure of peptidoglycan in gram-positive bacteria
Figure 4.14 Plasma membrane.
Outside
Inside
Figure 4.16 The principle of simple diffusion.
Figure 4.18 The principle of osmosis.
At beginning of osmotic pressure experiment
At equilibrium
Isotonic solution. No net movement of water occurs.
Hypotonic solution. Water moves into the cell. If the cell wall is strong, it contains the swelling. If the cell wall is weak or damaged, the cell bursts (osmotic lysis).
Glass tube
Rubber stopper Rubber band
Sucrose molecule Cellophane sack
Water molecule
Water
Solute Plasma membrane
E. coli in pure water:
• What is likely to move into or out
of the cell?
• What can the cell do about it?
Figure 4.20 Magnetosomes.
Figure 4.21 Formation of endospores by sporulation.
Sporulation, the process of endospore formation
An endospore of Bacillus subtilis
Spore septum begins to isolate newly replicated DNA and a small portion of cytoplasm.
Spore coat forms. Endospore is freed from cell.
Two membranes
Cytoplasm
Endospore
Ancient endospores
Ancient endospores
Clostridium botulinum is a strict anaerobe; that is, it is
killed by the molecular oxygen (O2) present in air. People
can die of botulism from eating foods in which C.
botulinum is growing.
• How does this bacterium survive on plants picked for
human consumption?
• Why are home-canned foods most often the source of
botulism?
(Tortora, 11th ed., p. 110)
Figure 4.27 Mitochondria.
Matrix Cristae Inner
membrane Outer membrane
Figure 4.28 Chloroplasts.
Applications of Microbiology 4.1 Mixotricha, a protozoan that lives in the termite gut.
Applications of Microbiology 4.2 Arrangements of bacteria on the surfaces of two protozoans.
Protozoan flagella
Spirochetes
Bracket
Protozoan surface
Filament composed of overlapping flagella
Rod-shaped bacteria in grooves
Protozoan surface
Termite gut symbionts: https://www.youtube.com/watch?v=HOx7SDdIqyU
kennethnoll.uconn.edu
Termite gut symbionts
kennethnoll.uconn.edu
Termite gut symbionts