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MICROBIOLOGY Cell Biology of Bacteria Instructor Terry Wiseth Northland Community & Technical College BACTERIAL FACTS Scientists have named and described more than 4,000 species of bacteria New ones are discovered so rapidly, however, they estimate the number of unknown species in the millions Almost every time scientists search among bacteria in a soil or water sample, they discover previously unknown species 2 BACTERIAL FACTS The overwhelming majority of bacteria are harmless to humans or animals Bacteria get virus infections Antibiotics and other bacteria-derived materials are the basis of a $50 billion annual market for biotechnology products Oil spills are cleaned primarily by bacteria that feed on oil 3 BACTERIAL FACTS About 10 percent of human body weight and 50 percent of the content of the human colon is made up of bacteria (Escherichia coli) each square centimeter of human skin hosts an average of 100,000 bacteria Washing removes many, but they reproduce so quickly--doubling every 20 minutes--that the population is restored in hours 4 BACTERIAL FACTS So many bacteria live underground that their total weight has been estimated at 100 trillion tons If these microbes were spread over Earth's land surface, they would make a layer five feet thick 5 CLASSIFICATION Microbes organisms smaller than the eye can detect bacteria fungi protists virus 6 CELL TYPES Prokaryotes Eukaryotes Viruses 7 PROKARYOTES Monera bacteria 1 micron diameter 8 EUKARYOTES algae, protozoa and fungi 5 - 100 microns 9 VIRUSES neither prokaryotes nor eukaryotes informational parasites each kingdom has its own associated viruses 10 MICROBIAL SIZE Virus 0.05 to 0.1 microns Bacteria 0.5 to 1.5 microns Red blood cell 5 microns Sperm 60 microns 11 MICROBIOLOGY disease agriculture food and drink chemical products basic research biotechnology 12 PROKARYOTES VS EUKARYOTES CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 14 CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 15 CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 16 CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 17 CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 18 CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 19 CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 20 CELL CHARACTERISTICS Prokaryote Eukaryote Chromosome Single circular Chromosome location Nucleoid (no membrane) Nucleolus Absent Chromosome Paired linear Chromosome location Nucleus (membrane present) Nucleolus Present Extra chromosomal DNA in Plasmid Extra chromosomal DNA in Mitochondria and Chloroplast Cellular Respiration in Mitochondria Undulating flagella, cilia, amoeboid movement Ribosome in organelles Cellular Respiration in Cell membrane Locomotion Rotating flagella Ribosome in cytoplasm 21 BACTERIAL SHAPE BACTERIA SHAPE range in size from 0.20 to 2.0 micrometers in diameter 1) Bacillus 2) Spiral 3) Cocci 23 BACILLUS 1) Bacillus Rod shape Diplobacilli Two bacilli together Streptobacilli Chains of bacilli Vibrios curved rods 24 BACILLUS Escherichia coli 25 SPIRAL 2) Spiral spirillia Spiral, helical, corkscrew shape that is rigid spirochete the organism is flexible and undulating 26 COCCI 3) Cocci spherical shaped diplococci remain in pairs streptococci chains staphylococci clusters 27 COCCI Moraxella catarrhallis inhabitant of the upper respiratory tract, especially the nasal cavity notice some are in the diploid state 28 BACTERIAL CELL WALL CELL MEMBRANE phospholipid bilayer integral and peripheral proteins embedded maintains the selective permeability of the cell has respiratory enzymes 30 CELL WALL cell wall surrounds the cell membrane Structurally, the wall is necessary for 1) maintain shape 2) counter osmotic pressures 3) attachment sites for bacteriophages 4) platform for surface appendages 31 CELL WALL 1) Maintaining the cell's characteristic shape the rigid wall compensates for the flexibility of the phospholipid membrane and keeps the cell from assuming a spherical shape 32 CELL WALL 2) Countering the effects of osmotic pressure the strength of the wall is responsible for keeping the cell from bursting when the intracellular osmolarity is much greater than the extracellular osmolarity 33 CELL WALL 3) Providing attachment sites for bacteriophages teichoic acids attached to the outer surface of the wall are like landing pads for viruses that infect bacteria 34 CELL WALL 4) Providing a rigid platform for surface appendages flagella, fimbriae, and pili all emanate from the wall and extend beyond it 35 CELL WALL cell walls of all bacteria are not identical cell wall composition is one of the most important factors in bacterial species analysis and differentiation clinically contributes to ability to cause disease site of action of antibiotics There are two major types of walls: Gram-positive Gram-negative 36 GRAM POSITIVE Has a thick peptidoglycan layer 90% of the Gram-positive cell wall is comprised of peptidoglycan two types of teichoic acids 37 GRAM POSITIVE 1) Lipoteichoic acid on the surface, embedded in the peptidoglycan layer linked to the cytoplasmic membrane 38 GRAM POSITIVE 2) Wall teichoic acid on the surface linked to only the peptidoglycan layer 39 GRAM POSITIVE 40 GRAM NEGATIVE cell wall of Gram-negative bacteria is much thinner comprised of only 20% peptidoglycan have two unique regions which surround the outer plasma membrane: periplasmic space lipopolysaccharide layer 41 GRAM NEGATIVE a thin peptidoglycan layer an outer membrane attached to the peptidoglycan layer by lipoproteins 42 GRAM NEGATIVE the outer membrane is made of protein, phospholipid and lipopolysaccharide the lipid portion is embedded in the phospholipid The lipid is toxic 43 GRAM NEGATIVE The cell wall has channels called Porins for the transport of low molecular weight substances 44 GRAM NEGATIVE periplasmic space between the cytoplasmic membrane and the cell wall hydrolytic enzymes antibiotic inactivating enzymes transport proteins 45 GRAM NEGATIVE Strong negative charge assists in: evading phagocytosis evade the complement system provides increased barrier to: antibiotics, lysozymes, detergents 46 GRAM NEGATIVE provides more attachment sites for: virus harmful substances more susceptible to mechanical breakage lipid A endotoxin is toxic to host 47 CELL WALL the cell wall is not a regulatory structure like the cell membrane though it is porous, it is not selectively permeable and will let anything pass that can fit through its gaps 48 EXTRACELLULAR MATRIX attached to the cell wall made of polysaccharide or polypeptide, or a combination of both form a viscous layer capsule slime layer 49 CAPSULE Capsule thick, structured and adheres strongly to the cell wall Adhere to surfaces to form colonies Antiphagocytic Antigenic Protect the organism from dehydration 50 CAPSULE 51 SLIME LAYER Slime layer disorganized and loosely attached to the cell wall Staphylococcus mutans causes dental caries 52 MOVEMENT Flagellum Made of the protein flagellin rotation is for swimming towards an attractant water is as viscous as syrup for a bacteria able to move 50 microns/sec 100X bacterial body length/sec fish able to swim only 10X body length/sec 53 MOVEMENT Axial Filaments found in Spirochetes similar to flagella attached throughout the body length 54 PILI made of the protein pilin virulence factors project from the cell surface Conjugation Pili for the transfer of extrachromosomal DNA between donor and recipient 55 FIMBRIAE used for attachment to surfaces more numerous than pili 56 CYTOPLASMIC STRUCTURES Nucleoid area of concentrated DNA no nuclear membrane The DNA is single circular double stranded without proteins 57 CYTOPLASMIC STRUCTURES Ribosomes cytoplasmic, not attached to organelles Plasmids Extrachromosomal loops of DNA some code for drug resistance toxins 58 TYPICAL BACTERIA 59 ENDOSPORES Metabolically inactive may produce endospores under environmental stress lack of water lack of nutrients severe temperature changes Clostridium Bacillus 60 ENDOSPORES Spores can be dormant for many years can survive extreme heat desiccation radiation toxic chemicals 61 ENDOSPORES when conditions become favorable they revert to an active state Spore germination is activated by heat in the presence of moistures 62 END CELL BIOLOGY OF BACTERIA
