BACTERIA

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BACTERIA

• Biology Chapter 18.2

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Bacteria are very small
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This is a pore in human skin and the yellow
spheres are bacteria
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Bacteria are very small compar-ed to cells with
nuclei
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Bacteria compared to a white blood cell that is
going to eat it
Bacteria
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Clean skin has about 20 million bacteria per
square inch
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Evolution/Classification

• Most numerous on Earth
• Most Ancient
• Microscopic Prokaryotes
• Evolution has yielded many species adapted to
  survive where no other organisms can.
• Grouped based on
• Structure, physiology, molec. Compositionreaction
  to specific types of stain.
• Eubacteria Germs/bacteria
• Archaebacteria

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Kingdom Archaebacteria

• First discovered in extreme environments
• Methanogens Harvest energy by converting H2 and
  CO2 into methane gas
• Anaerobic, live in intestinal tracts
• Extreme halophiles Salt loving, live in Great
  Salt Lake, and Dead sea.
• Thermoacidophiles Live in acid environments and
  high temps.
• Hot Springs, volcanic vents

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Volcanic vents on the sea floor
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Chemosynthetic bacteria use the sulfur in the
smoke for energy to make ATP.
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The red color of this snow is due to a blue-green
bacteria
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Kingdom Eubacteria

• Can have one of three basic shapes

• Bacilli rod-shaped
• Spirilla spiral-shaped
• Cocci sphere-shaped

Staphylococci grape-like clusters
Streptococci in chains
SHOW ME
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BACTERIA PICS
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Bacillus bacteria are rod or sausage shaped
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Coccus bacteria are sphere or ball shaped
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Spirillium bacteria have a corkscrew shape
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Diplo-bacteria occur in pairs, such as the
diplococcus bacteria that causes gonorrhea
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Staphylo - bacteria occur in clumps, such as this
staphylococcus bacteria that causes common
infections of cuts
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Strepto- bacteria occur in chains of bacteria,
such as this streptococcus bacteria that causes
some types of sore throats
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Spirillium bacteria
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Diplobacillus bacteria
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Streptococcus bacteria
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Staphylococcus bacteria
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The tip of a needle The red and yellow dots are
bacteria
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Gram Stain

• Gram-positive retain stain and appear purple
• Have thicker layer in cell wall.
• Gram-negative do not retain stain and take second
  pink stain instead.

Phylum Shape Motility Metabolism Gram reacion
Cyanobacteria Bacilli, Cocci Gliding, some non-motile Aerobic, photosynthetic autotrophic Gram-negative
Spirochetes Spirals Corkscrew Aerobic, and anaerobic heterotrophic Gram-negative
Gram-Pos Bacilli, cocci Flagella some non-motile Aer/anaer. heterotrophic, photosynthetic Mostly gram-positive
Proteobacteria Bacilli, cocci, spiral Flagella some non-motile Aer/anaer. heterotrophic, photosynthetic autotrophic Gram-negative
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STRUCTURE OF BACTERIA
Structure Function
Cell Wall Protects and gives shape
Outer Membrane Protects against antibodies (Gram Neg. Only)
Cell Membrane Regulates movement of materials, contains enzymes important to cellular respiration
Cytoplasm Contains DNA, ribosomes, essential compounds
Chromo-some Carries genetic information
Plasmid Contains some genes obtained through recomb.
Capsule Slime Layer Protects the cell and assist in attaching cell to other surfaces
Endospore Protects cell agains harsh enviornments
Pilus Assists the cell in attaching to other surfaces
Flagellum Moves the cell
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No Nucleus-DNA in Cytoplasm
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Nutrition and Growth

• Heterotrophic or Autotrophic
• Some are Photoautotrophs Use sunlight for
  Energy
• Some are Chemoautotrophs.
• Many are Obligate Anaerobes.
• Oxygen Death
• Ex. Clostridium tetani Tetanus
• Some are Faculatative Anaerobes
• With or without Oxygen
• Ex. Escherichia Coli
• Some are Obligate Aerobes
• Ex.) Mycobacterium tuberculosis
• Temperature requirements
• Some are Thermophilic, Some prefer acidic envmt.

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These heterotrophic bacteria digest oil --
remember oil is partially decayed plant and
animal cells
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REPRODUCTION IN BACTERIA (please add to
notes)
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No Nucleus-DNA in Cytoplasm
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BACTERIA REPRODUCES BY FISSION
First the chromosomal DNA makes a copy
The DNA replicates
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NEXT THE CYTOPLASM AND CELL DIVIDES
The two resulting cells are exactly the same
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In addition to the large chromosomal DNA,
bacteria have many small loops of DNA called
Plasmids
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Genetic Recombination

• Nonreproductive Methods bacteria can acquire new
  genetic material.

Characteristic Transformation Conjugation Transduction
Method of DNA Transfer Across cell wall and cell membrane of recepient Through a conjugation bridge between two cells By a virus
Plasmid transfer Yes Yes Not likely
Chromosome transfer No Sometimes No
Antibiotic resistance acquired Yes Yes Sometimes
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TRANSFORMATION
This plasmid of DNA is new to the bacteria
added by transformation! Produces the glowing
protein
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CONJUGATION
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TRANSDUCTION
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Bacteria and Disease
Disease Pathogen Areas affected Mode of transmission
Botulism Clostridium botulinum Nerves Improperly preserved food
Cholera Vibrio cholerae Intestine Contaminated water
Dental Caries Streptococcus mutans, sanguis, salivarius Teeth Environment to mouth
Gonorrhea Neisseria gonorrhoeae Urethra, fallopian Sexual contact
Lyme disease Berrelia burgdorferi Skin, joints Tick bite
Rocky Mountain SF Rickettsia recketsii Blood, skin Tick bite
Salmonella Salmonella Intestine Contaminated food, water
Strep throat Streptococcus pyogenes URT, blood, skin Sneezes, coughs, etc.
Tetanus Costridium tetani Nerves Contaminated wounds
Tuberculosis Mycobacterium tuberculosis Lung, bones coughs
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Some bacteria cause diseases --Disease causing
bacteria are call
PATHOGENIC
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Helicobacter pylori is the pathogenic
bacteria that can causes ulcers
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Leprosy is a bacterial infection that decreases
blood flow to the extremities resulting in the
deterioration of toes, ears, the nose and the
fingers.
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BOTULISM
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CHOLERA
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DENTAL CARIES
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ROCKY MOUNTAIN SF
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LYME DISEASE
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SALMONELLA
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STREP THROAT
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TETANUS
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TUBERCULOSIS
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Common Antibiotics
Antibiotic Mechanism Target bacteria
Penicillin Inhibits cell wall synthesis Gram Positive
Ampicillin Inhibits cell wall synthesis Broad spectrum
Bacitracin Inhibits cell wall synthesis Gram Positive Skin Ointment
Cephalosporin Inhibits cell wall synthesis Gram Positive
Tetracycline Inhibits Protein Synthesis Broad spectrum
Streptomycin Inhibits Protein Synthesis Gram Neg. tuberculosis
Sulfa drug Inhibits cell metabolism Bacterial meningitis, UTI
Rifampin Inhibits RNA synthesis Gram Pos., some Neg.
Quinolines Inhibits DNA Synthesis UTI
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Some Final Information

• Because antibiotics have been overused, many
  diseases that were once easy to treat are
  becoming more difficult to treat.
• Some Bacteria are Useful
• Ex.) Producing and Processing food
• Breaking down dead organic material
• Make unripened cheese like ricotta and cottage by
  breaking down the protein in milk.