Bacteria:

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Bacteria

• Classification and Structure

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What are the 6 Kingdoms?

• Archaebacteria
• Eubacteria
• Protists
• Fungi
• Plants
• Animals

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We are looking at the first two

• Archaebacteria Extremists.
• Eubacteria Larger of the two kingdoms. Contain a
  variety of organisms

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Archaebacteria

• Live in extreme locations
• Oxygen-free environments
• Concentrated salt-water
• Hot, acidic water

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EUBACTERIA

• Bacteria all are prokaryotic meaning they do
  not have a nucleus.
• Bacteria are unicellullar cells (one cell only)
• They are found almost everywhere
• -water -air
• -soil -food
• -skin -inside the body
• -on most objects

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Clean skin has about 20 million bacteria per
square inch
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The tip of a needle The red and yellow dots are
bacteria
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Structure of Bacteria

• Two parts to Bacteria Structure
• Arrangement
• Shape

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3 Shapes of Bacteria
Bacteria are classified by shape into 3 groups
Spiral spirilla rod-shaped bacilli,
bacillus Round cocci
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7 Major parts of a Bacteria Cell

• Capsule
• Cell wall
• Ribosomes
• Nucleoid
• Flagella
• Pilli
• Cytoplasm

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CAPSULE
Capsule

• keeps the cell from drying out and helps it
  stick to food or other cells

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CELL WALL
Cell wall

• Thick outer covering that maintains the overall
  shape of the bacterial cell

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Cell Wall determined by Gram Staining. Gram
positive stain purple because they have
peptidoglycan in their cell wall. Thicker cell
wall, but less pathogenic. Gram negative stain
red because they lack peptidoglycan in their cell
wall. Thinner cell wall, but generally more
pathogenic .
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• Penicillin kills bacteria by making holes in
  their cell walls. Unfortunately, many bacteria
  have developed resistance to this antibiotic.

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RIBOSOMES
Ribosomes

• cell part where proteins are made
• Ribosomes give the cytoplasm of bacteria a
  granular appearance in electron micrographs

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NUCLEOID
Nucleoid

• a ring made up of DNA

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PILLI
Pilli

• hollow hair-like structures made of protein
• allows bacteria to attach to other cells.
• Pilli-singular
• Pillus-plural

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FLAGELLA
Flagella

• a whip-like tail that some bacteria have for
  locomotion

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Classification

• Movement
• Non-motile
• Flagella whiplike structure
• Gliding secrete a slime

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CYTOPLASM
Cytoplasm

• clear jelly-like material that makes up most of
  the cell

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Metabolic Diversity

• Chemoheterotrophs - take in organic molecules
  for energy.
• Photoheterotrophs - use sunlight and
  photosynthesis for energy but must also take in
  organic molecules for energy.
• Photoautotrphs- Use sunlight energy and
  photosynthesis to make their own food.
• chemoautotrophs - use carbondioxide to make
  energy but do not require light.

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Energy Release

• Oblique aerobes require oxygen for life.
  Example Mycobacterium tuberculosis
• oblique anaerobes must live in the absence of
  oxygen. Example Clostridium botulinum
• Facultative anaerobes Can live with or without
  oxygen. Example Escherichia coli

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Reproduction of Bacteria

• Binary Fission- the process of one organism
  dividing into two organisms
• Fission is a type of asexual reproduction

• Asexual reproduction- reproduction of a living
  thing from only one parent

How?... The one main (circular) chromosome makes
a copy of itself Then it divides into two
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Reproduction of Bacteria
BINARY FISSION
Completed
Bacteria dividing
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Reproduction of Bacteria

• The time of reproduction depends on how desirable
  the conditions are
• Bacteria can rapidly reproduce themselves in
  warm, dark, and moist conditions
• Some can reproduce every 20 minutes
• (one bacteria could be an ancestor to one
  million bacteria in six hours)

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Bacterial Cell Nucleiod DNA Ring
DNA replication
Cell wall synthesis
Binary Fission
Cell separation
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Spore formation

• Endospore-
• a thick celled structure that forms inside
• the cell

• they are the major cause of food poisoning

• allows the bacteria to survive for many years

• they can withstand boiling, freezing, and
  extremely dry conditions

• it encloses all the nuclear materials
• and some cytoplasm

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Bacteria Survival
Bacillus subtilis Endospore-the black section in
the middle

• highly resistant structures
• can withstand radiation, UV light, and boiling at
  120oC for 15 minutes.

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Bacteria Survival Nutrition

• parasites bacteria that feed on living things
• saprophytes use dead materials for food
  (exclusively)
• decomposers get food from breaking down dead
  matter into simple chemicals
• important- because they send minerals and other
  materials back into the soil so other organisms
  can use them

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Harmful Bacteria

• some bacteria cause diseases
• Animals can pass diseases to humans
• Communicable Disease
• Disease passed from one organism to another
• This can happen in several ways
• Air
• Touching clothing, food, silverware, or
  toothbrush
• Drinking water that contains bacteria

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Harmful Bacteria

Human tooth with accumulation of bacterial plaque
(smooth areas) and calcified tartar (rough areas)
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Helpful Bacteria (Importance of bacteria)

• Decomposers help recycle nutrients into the soil
  for other organisms to grow
• Bacteria grow in the stomach of a cow to break
  down grass and hay (cellulose)
• Most are used to make antibiotics
• Some bacteria help make insulin
• Used to make industrial chemicals

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Helpful Bacteria

E.coli on small intestines
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Helpful Bacteria

• Used to treat sewage          
• Organic waste is consumed by the bacteria, used
  as nutrients by the bacteria, and is no longer
  present to produce odors, sludge, pollution, or
  unsightly mess.
• Foods like yogurt, cottage Swiss cheese, sour
  cream, buttermilk are made from bacteria that
  grows in milk

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Controlling Bacteria
3 ways to control bacteria
1) Canning- the process of sealing food in
airtight cans or jars after killing bacteria

• endospores are killed during this process

2) Pasteurization- process of heating milk to
kill harmful bacteria
3) Dehydration- removing water from food

• Bacteria cant grow when H2O is removed

• example uncooked noodles cold cereal

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Controlling Bacteria Antiseptic vs. Disinfectants
Antiseptic- chemicals that kill bacteria on
living things

• means against infection

Examples iodine, hydrogen peroxide, alcohol,
soap, mouthwash
Disinfectants- stronger chemicals that destroy
bacteria on objects or nonliving things
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Summary on the 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
Chromosome 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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Bacteria and Diseases.

• Some bacteria cause diseases --Disease causing
  bacteria are called PATHOGENS.

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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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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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DENTAL CARIES
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CHOLERA
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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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Plants, Fungi Animal Cells

• Plants Only
• Cell wall of cellulose
• Central vacuole
• Chloroplasts

• Animals Only
• Lysosomes
• Centrioles

• Fungi Only
• Cell wall of chitin
• Central vacuole
• No chloroplasts