BACTERIA IN YOUR SOCKS

BACTERIA ON YOUR CLOTHESVIRUS IN YOUR NOSE

Look out, youre surrounded! Bacteria and viruses are all around us.Examples:Bacteria Used in Food MakingBacteria used in Digestion (E. coli)Some bacteria cause disease (pathogenic)ALL viruses cause disease (all pathogenic)BACTERIA & VIRUSESBacteriaStructureLIVING, microscopic and lacking internal membranesProkaryoticBacteria cells are usually much smaller than plant and animal cells and do not contain as many internal structures.

Bacteria cells contain cytoplasm surrounded by a cell membrane and a cell wall.

Its hereditary material is found in the cytoplasm.

Some bacteria have a thick, gel-like capsule around the cell wall to protect it.

Bacteria in moist environments have whiplike tails called flagella that help them move.

Let's reviewwhat we knowabout bacteria.ArchaebacteriaandEubacteriaBacteria that live in harsh environments (extremophiles) where few kinds of other organisms can live:* methanogens:* thermophiles:* halophilesArchaebacteriaThe larger of the two groups of bacteria. These usually live in less harsh environments. EubacteriaMost bacteria are beneficial.

All bacteria that cause known diseases are eubacteria.

Bacteria can be classified according to:ShapeCell WallsMovementMetabolic diversity (the way they obtain energy)There arethree majorshapes of bacteria.

Sphere-shaped bacteria (cocci) sometimes grow in chains or in clumps like a bunch of grapes.Streptococcus(strep throat)Staphylococci (responsible for "staph" infections and gangrene)CocciRod-shaped bacteria (bacilli) can also form in chains. Some types of these bacteria also have whiplike structures called flagella to help them move around.

Escherichia coli or E.coli(found in the intestines of mammals)Salmonella typhi(causes typhoid fever and food poisoning)

Bacilli

Spiral-shaped bacteria (spirilla) can use their shape to propel themselves by twisting like a corkscrew.Treponema pallidumcholera(syphilis)Borrelia burgdorferi (Lyme disease)SpirillaBacteria areoften foundin groupsor colonies.BacterialColony TypesMonococcus - a single spherical bacterium, living alone

Diplococcus - two spherical bacteria, living in a pair

Streptococcus: chains of nearly spherical bacteria.

Streptobacillus: chains of rod-shaped bacteria.

Staphylococcus : spherical bacterium occurring in grape-like clusters.

Staphylobacillus - a cluster of rod shaped bacteria

StreptococcusStreptococcus: chains of nearly spherical bacteria.

StreptobacillusStreptobacillus: chains of rod-shaped bacteria.

Staphylococcus : spherical bacterium occurring in grape-like clusters.StaphlococcusOther waysto classifyand identifybacteria...Some cell walls change colors when stained and other cell walls do not. The bacteria that have the stained cell walls are called Gram positive (have much peptidoglycan in cell walls). The bacteria with cell walls that do not stain are called Gram negative (no peptidoglycan). Doctors regularly use gram staining to select the proper antibiotic to treat bacterial infections.

Gram stainHow dobacteriareproduce?Bacteria reproduce by means of binary fission, in which a copy of the DNA is made and then the outer membrane of the bacterium begins to grow inward and divides into two identical cells. Also, to exchange genetic material one bacterium attaches itself to another bacterium and introduces DNA directly into it by means of a pilus through the process of conjugation.*SmartNotebook videoSome bacteria are able to produce thick walls around themselves when evironmental conditions are unfavorable. They form an endospore and can become dormant for hundreds of years.

Conjugation

Bacteria dividingbacteria require oxygen to survive

bacteria can live with or without oxygen

bacteria use other organisms for energy

bacteria produce their own food through photosynthesisAnaerobicAerobicHeterotrophicAutotrophic

Bacteriaand yourHealthBacteria doesnt just make you sick, it can also keep you healthy. You cannot survive without some bacteria living in or on your body.(Ex: E. coli in digestive tract)

Some bacteria produce chemicals called antibiotics that limit the growth of other bacteria. Overuse of antibiotics has led to more resistant bacteria.

Bacteria that cause disease are called pathogens.A vaccine is made from a deadened or weakenend version of a virus or bacterium. Immunization with certain vaccines can prevent other bacterial diseases.PathogenMany pathogens produce poisons called toxins as they grow in your body or as they grow in food that you might eat.ToxinsBotulism is a type of food poisoning that is the result of a toxin produced by bacteria whose endospores can survive in canned food.

Bacteriaand IndustryCheeses, buttermilk, chocolate, vinegar, sauerkrautFood madewith bacteria

Pasteurization is a process that is used to kill most harmful bacteria and lengthen the time foods can be stored without spoiling.

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Quiz time! At any given time you have about a billion bacteria on every tooth in your mouth.

True.

Warm and moist, your mouth is a breeding ground for bacteria. Some of these bacteria feed on bits of food trapped between the teeth. Immediately after brushing you still have up to a hundred thousand bacteria living on each tooth!

Photograph by David Scharf/Peter Arnold Inc.

Swamps produce terrible odors because owls shower them with nasty-smelling antibacterial sprays.

False.

Swampy areas are filled with wet, rotting vegetation. Plants rot as bacteria feed on them. In the process of feeding in these watery areas where there is very little air, bacteria known as methanogens produce a number of gasesincluding methane and sulfides, which smell like rotten eggs.

Art by Scott Angle

There are millions of species of bacteria that can make people ill.

False. Of the thousands of species of bacteria, only a handful make people ill. The rod-shaped bacteria above cause bubonic plague, a disease that is carried by rodents and fleas. Bubonic plague kills about 1,500 people a year worldwide. This bacteria tends to get more attention than the more common good bacteria.

Photograph by CNRI/Science Photo Library/Photo Researchers, Inc.

People use bacteria to clean up after oil spills.

True.Scientists have discovered that several kinds of bacteria can live on a diet of oil. Now if an oil pipe leaks, spilling its contents on the ground, cleanup crews know how to deal with the mess. They cart in bacteria-rich soil and pile it onto the contaminated site. Then they sit back and let the bacteria eat the oil up!

Art by Scott Angle

Bacteria dont often reproduce.

False.

Bacteria reproduce by dividing, some lickety-splitting in half once every 12 to 20 minutes. At that rate, one bacterium can produce billions of offspring in a day.

Photograph by Manfred Kage / Peter Arnold, Inc.

Let's makeBACTERIA!Viral Structure Is a Virus Alive?Viruses do NOT have all the characteristics of life (no cells/no machinery for protein synthesis) and are therefore not considered to be alive.

613Viral StructureALL Viruses consist of: segments of a nucleic acid (DNA or RNA) contained in a protein coat (capsid).

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Structure of AdenovirusCauses Respiratory DiseasesPolyhedral Shape,Some viruses have an envelope surrounding the capsid.

Outside the envelope glycoproteins are attached.

Glycoproteins on the virus attach to receptors on the cell surface.

When this happens, the cell allows the virus to enter.

EnvelopeGlycoproteins

Structures of TMV and Influenza VirusCauses Tobacco Mosaic Virus and the FluRod shapedStructure of BacteriophageA bacteriophage is a virus that infects a bacteria.

Bacteriophage Attacking CellStructure of HIVCauses AIDS

How do viruses reproduce? Viral ReproductionViruses lack enzymes and structures to make proteins (no ribosomes). Therefore viruses, depend on living cells to replicate and use the energy of the host cell to carry out reproductive processes.

They enter a cell by: injecting their genetic material into the cell

slipping through tears in a plant cell wall

binding to molecules on the cell surface and triggering endocytosis (cell engulfment)705

2 Viral Pathways

http://www.npr.org/templates/story/story.php?storyId=114075029&sc=nl&cc=es-20091129Follow the link below to view an animation of a virus infecting human cells:

A glycoprotein on HIV attaches to the CD4 receptor on a cell.

2) A second HIV glycoprotein attaches to the CCR5 receptor on the cell.HIV InfectionHIV infects cells called macrophages in your body!3)The cell then allows the viral capsid to enter the cell and the viral RNA is released into the cell.

4)The viral RNA is converted to viral DNA using an enzyme known as reverse transcriptase.

5) The viral DNA integrates into the host cell DNA.

6) The viral DNA will use the host cells ribosomes to make more copies of the virus.

7) The new viruses are released from the host cell by budding.

8) Newly released viruses infect more cells.

After a period of time, the HIV viruses will mutate and begin to infect T-cells.

T-cells die once infected with HIV.

T-cells are a major component of the bodys immune system.

The disease AIDS forms as the immune system becomes weakened as T-cells are being destructed.

Virus is Latin for "poison"ALL viruses are PATHOGENIC!Do you know what this means?