Since bacteria Since bacteria have no true have no true nucleus or nucleus or organelles organelles surrounded by surrounded by a membrane, a membrane, this makes this makes them them prokaryotic prokaryotic cellscells..

There are two There are two kingdoms of bacteria: kingdoms of bacteria:

Kingdom Archaebacteria Kingdom Archaebacteria – live in extreme – live in extreme environments (salt lakes, environments (salt lakes, volcanoes, ocean vents)volcanoes, ocean vents)

Kingdom Eubacteria Kingdom Eubacteria – these are common – these are common bacteria and are bacteria and are often called germs.often called germs.

Parts of a bacteria cell: Parts of a bacteria cell:

Cell wall – Cell wall – gives bacteria gives bacteria their shape.their shape.

Cell membrane –Cell membrane – regulates what regulates what goes in and out of the cellgoes in and out of the cell. .

CytoplasmCytoplasm –– water-like substance water-like substance that fills the cell and aids in that fills the cell and aids in storage.storage.

Parts of a bacteria cell: Parts of a bacteria cell:

DNA - a single, circular chromosome located in the cytoplasm.

Remember, bacteria cells do not have a nucleus.

Parts of a bacteria cell: Parts of a bacteria cell:

Capsule – a thick, gel-like, protective coating on somebacteria cells.

Pili - short, hair-like protein structures on the surface of some bacteria that help them stick to host cells.

Parts of a bacteria cell: Parts of a bacteria cell:

Flagella - long protein structures that turn to propel some bacteria cells.

Capsule -Capsule - a thick, gel-like, a thick, gel-like, protective coating on some protective coating on some bacteria cells. bacteria cells.

Shape: Shape:

Grouping: Grouping:

Respiration: Respiration:

Gram Stain Gram Stain Characteristics:Characteristics:

CocciCocci - round - round bacterial cells. bacterial cells.

BacilliBacilli - rod- - rod-shaped bacterial shaped bacterial cells. cells.

SpirilliSpirilli - spiral- - spiral-shaped bacterial shaped bacterial cells.cells.

diplodiplo - - a prefix used a prefix used with the shape name with the shape name to indicate pairing of to indicate pairing of cellscells. .

streptostrepto - a prefix - a prefix used with the shape used with the shape name to indicate name to indicate filaments. filaments.

staphylostaphylo - - a prefix a prefix used with the shape used with the shape name to indicate name to indicate clusters.clusters.

Obligate aerobes - Obligate aerobes - cannot cannot survive without atmospheric survive without atmospheric oxygenoxygen

Obligate anaerobes - Obligate anaerobes - cannot cannot survive in the presence of survive in the presence of atmospheric oxygen.atmospheric oxygen.

Facultative anaerobes - Facultative anaerobes - can live can live withwith or or withoutwithout atmospheric atmospheric oxygen.oxygen.

Gram-positive bacteria have a Gram-positive bacteria have a thick peptide layer, retain the thick peptide layer, retain the crystal violet, and appear purple crystal violet, and appear purple when viewed under a microscope. when viewed under a microscope.

Gram-negative bacteria have a Gram-negative bacteria have a thin peptide layer, take up the thin peptide layer, take up the pink stain, and appear pink when pink stain, and appear pink when viewed under a microscope.viewed under a microscope.

Many antibiotics have no effect Many antibiotics have no effect on gram-negative bacteria.on gram-negative bacteria.

Most are heterotrophic because they use food produced by other organisms.

Bacteria are often called decomposers because they feed on dead or decaying organic matter.

Some are Some are autotrophicautotrophic - able - able to produce their own food.to produce their own food.

ChemoautotrophsChemoautotrophs - use - use energy from chemical energy from chemical reactions to make their reactions to make their food. food.

PhotoautotrophsPhotoautotrophs -- use use sunlight as a source sunlight as a source of energy like plants.of energy like plants.

Asexual, by binary fission - the Asexual, by binary fission - the DNA replicates and then the cell DNA replicates and then the cell pinches inward and splits in pinches inward and splits in two. two.

ConjugationConjugation - two cells - two cells exchange a portion of exchange a portion of their DNA across a their DNA across a bridge formed between bridge formed between the cells. Following this the cells. Following this exchange, the cell goes exchange, the cell goes through binary fission. through binary fission.

While this increases the While this increases the genetic variability in the genetic variability in the organisms, it is not true organisms, it is not true sexual reproduction. sexual reproduction.

Endospores - during Endospores - during adverse conditions, adverse conditions, the DNA is encased in a the DNA is encased in a protective envelope. This protective envelope. This endospore can lie dormant endospore can lie dormant (like a seed) for years or (like a seed) for years or until favorable conditions until favorable conditions returnreturn.

Happens only in gram+ bacillus

Trillions of Trillions of “good” “good” bacteria live in bacteria live in your body – your body – mostly in your mostly in your intestines.intestines. Lactobacillus

acidophilus

It protects the intestines, It protects the intestines, aids in digestion, builds aids in digestion, builds immunity to food immunity to food allergies, and lowers allergies, and lowers cholesterol. cholesterol.

Bacteria is also Bacteria is also useful in useful in making many making many of our foods.of our foods.

Examples: Swiss cheese, Examples: Swiss cheese, yogurt, vinegar (used in yogurt, vinegar (used in making pickles), sauerkrautmaking pickles), sauerkraut

Bacteria are also Bacteria are also useful in making useful in making medicines and medicines and antibiotics that antibiotics that destroy other types destroy other types of bacteria. of bacteria.

Antibiotics are Antibiotics are chemicals that chemicals that inhibitinhibit the the growth of some growth of some bacteria.bacteria.

Two common antibiotics are: Two common antibiotics are:

PenicillinPenicillin is an antibiotic that is an antibiotic that interferes with cell wall interferes with cell wall synthesis. synthesis.

TetracyclineTetracycline is an antibiotic that is an antibiotic that interferes with bacterial protein interferes with bacterial protein synthesis. synthesis.

Many Many antibiotics are antibiotics are derived from derived from chemicals that chemicals that bacteria and bacteria and fungi produce. fungi produce.

The over-use of The over-use of antibiotics through the antibiotics through the years has lead to some years has lead to some bacteria that are bacteria that are almost immune to almost immune to treatment with them.treatment with them.

Bacteria play Bacteria play an important an important role in our role in our environment:environment:

Bacteria are important to Bacteria are important to the Nitrogen Cycle.the Nitrogen Cycle.

Bacteria change nitrates, Bacteria change nitrates, nitrites and ammonia into nitrites and ammonia into a usable form of Nitrogen. a usable form of Nitrogen.

Bacteria play Bacteria play an important an important role in our role in our environment: environment:

Bacteria are Bacteria are decomposers- natures decomposers- natures recyclers! recyclers!

Bacteria cause many Bacteria cause many diseases in animals diseases in animals and plants. and plants.

Bacteria can enter the body Bacteria can enter the body through openings such as through openings such as the mouth, nose, and the mouth, nose, and eyes….. Also any open eyes….. Also any open wound.wound.

Botulism (Botulism (Bacillus botulinum ) ) creates a toxin that is creates a toxin that is found in inadequately found in inadequately prepared food.prepared food.

Salmonella causes Salmonella causes vomiting, diarrhea, and vomiting, diarrhea, and fever. Prevented by fully fever. Prevented by fully cooking eggs and poultry, cooking eggs and poultry, washing hands and cleaning washing hands and cleaning kitchen surfaces often. kitchen surfaces often.

Strep Throat (Strep Throat (Streptococcal bacteria) is ) is caused by a bacteria. caused by a bacteria.

Symptoms: fever, severe sore Symptoms: fever, severe sore throat, swollen glands.throat, swollen glands.

Necrotizing Fasciitis is caused Necrotizing Fasciitis is caused by a bacteria. by a bacteria.

This is a rare flesh eating This is a rare flesh eating disease that enters through disease that enters through openings in the skin.openings in the skin.

How can bacteria be How can bacteria be transmitted?transmitted?

Animal or Animal or Human Human CarriersCarriers

Insect CarriersInsect Carriers

Contaminated Contaminated Water or FoodWater or FoodFood that is Food that is

uncooked or uncooked or not fully not fully cookedcooked ContaminateContaminate

d Soild Soil

AirborneAirborne

Direct contactDirect contact

Indirect Indirect contactcontact