The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States

The vivid colors in the spring are the result of pigmented bacteria in the microbial mats that grow around the edges of the mineral-rich water

Unit 6: Bacteria and Viruses

Objective:

Do Now……. • Write down what you know about bacteria and viruses

Bacteria Viruses

Bacteria are: •Unicellular

•Divided into Two distinct groups

• Eubacteria

• Archaebacteria

•Prokaryotic…which means?

• What is the structure?

•able to Reproduce (2 ways)

• Binary Fission

• Conjunction

•Both good and bad

•Most can be treated with Antibiotics

Fact: Each square centimeter of your skin

averages about 100,000 bacteria. A single teaspoon of topsoil contains more than a billion (1,000,000,000) bacteria.

Two kingdoms of bacteria:

•Eubacteria – “true” bacteria,

live almost everywhere (fresh

water, salt water, land, in the

human body)

•Archaebacteria – oldest

organisms on earth, live in

extreme conditions (like hot

springs, anoxic

environments like thick

mud)

Prokaryotic vs. Eukaryotic

Prokaryotic

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Eukaryotic

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Make a list of the similarities and differences

Both

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Bacterial Structure

• Microscopic unicellular prokaryotes

• No nucleus or membrane-bound organelles

• Contain ribosomes

• a singular, circular piece of DNA (nucleiod)

• Have a flagella that allows them to move

• Some have a gelatinous layer called a capsule surrounding the cell wall

• pili (short, thicker outgrowths that help cell to attach to surfaces

Three bacterial shapes:

• Rod shaped are called bacilli

• Sphere shaped are called cocci

• Spiral shaped are called spirilla

• Bacteria can reproduce

asexually (mitosis) using

binary fission.

• Single chromosome

replicates & then cell

divides

• All new cells identical

(clones)

Reproduction:

Binary Fission

• Bacteria can reproduce

sexually using conjugation.

• Bacteria exchange

plasmid DNA through a tube.

• New cells NOT identical

• Can cause antibiotic

resistance

Reproduction:

Conjunction

Bacteria can also be categorized based on the way in

which bacteria can obtain energy:

heterotrophs – must take in food for energy

photoautotrophs - These are autotrophs that use the

sun’s energy to make food. Example: Cyanobacteria

chemoautotrophs – make energy from chemical

reactions involving hydrogen sulfide, sulfur, and nitrates. Do

not require the sun. example: bacteria near hydrothermal vents

ARE ALL BACTERIA BAD???? The good, the bad, and the evil!

Can you think of examples of “good” bacteria?

What about “bad” bacteria?

Some Good Bacteria

Bacteria are vital to maintaining the living

world. Some are producers that capture

energy by photosynthesis. Others are

decomposers that break down the nutrients

in the dead matter and the atmosphere.

Some bacteria are used in humans.

Decomposers

Obtain energy by breaking down the chemical elements inside other living or dead organisms. Some bacteria live in the intestines of humans and animals.

• Wastewater bacteria feed on everything from solid human waste matter to last night's leftovers.

• Help the ecosystem recycle nutrients

Nitrogen-fixing bacteria (Rhizobium)

• Found in nodules of soybeans, peanuts, alfalfa, and clover

• Plants need nitrogen to make amino acids(a macromolecule), which is a building block of protein

• Convert atmospheric nitrogen (N2) into ammonia (a form that plants can use), is called nitrogen fixation.

• Used in crop rotation

Human Uses

• Produce food, such as cheese and yogurt (lactic acid fermentation)

• Healthy intestinal bacteria

• Used to make medicine

• Bacteria that ingests petroleum can be used to help clean up a oil spill

Pathogens-disease causing (not good bacteria!)

• Called germs or “bugs”

• Cause disease

• Two ways in which bacteria cause disease: 1. Destroy living cells/tissues

Tuberculosis – destroys lung cells

2. Produce toxins (poisons) that interfere with cell functions

Strep Throat, releases toxins into bloodstream and causes a scarlet fever

How is bacteria spread?

• Bacteria can be moved by air and water

currents, and on any surface such as clothing, hands, or any object.

Bacteria Diseases

Streptococcus

Strep

throat

Staphylococcus

Pathogens

Prevention Methods

• Antibiotics

• Vaccines

• Sanitation

– Sterilization

– Disinfection

• Staying Healthy

• Food Storage

• Education

ANTIBIOTIC: A chemical that inhibits the growth of bacteria

Destroy the cell membrane /wall of the bacteria cell

Interfere with the bacteria cell’s chemical processes

Change the DNA of the bacteria ( can’t reproduce)

Antibiotics cannot treat viral infections

How do they work?

WHAT IS ANTIBACTERIAL RESISTANCE???

Misuse and overuse of these drugs, however, have

contributed to a phenomenon known as antibiotic

resistance. This resistance develops when

potentially harmful bacteria change in a way that

reduces or eliminates the effectiveness of

antibiotics

When antibiotics don't

work, the result can be

longer illnesses

more complicated illnesses

more doctor visits

the use of stronger and

more expensive drugs

more deaths caused by

bacterial infections

Vaccines

• Many bacterial diseases can be prevented by vaccines

• A vaccine is a preparation of weakened or killed pathogens.

• The vaccines helps you body produce antibodies to fight the disease.

Sanitation and Healthy Living

• Sterilization –

– Using high heat to destroy bacteria. (i.e. surgical instruments)

• Disinfection –

– Chemical solution that kill bacteria (i.e. cleaners)

• Overuse of antibacterial soaps may increase bacterial resistance.

• Wash You Hands and take care of

yourself !!! - Need I say more!

Food Storage and Processing Bacteria can cause food to spoil, prevention methods

should be used.

• Refrigerate food to slow down bacterial growth

• Cook food to recommended temperatures to kill

bacteria

Education

• Q: Why do you think education is important part of preventing the spread of disease?