Our Microscopic World

smallest, simplest organism, unicellular Most abundant organism Prokaryotic cell…very simple, NO nucleus,

ribosomes, cytoplasm, circular DNA, cell membrane, some have cell walls

Archaebacteria “old” bacteria Found in

inhospitable conditions

Three types1. Heat lovers…found in hot springs, paint pots, ocean vents2. Methane makers…found in swamps3. Salt lovers…found in high salt environments…ie: Dead Sea

Eubacteria Most common Found everywhere Grouped by how

obtain food1. producers…make own food2. decomposers…consumer that breaks down matter to obtain nutrients3. parasites…consumer that obtain nutrients by feeding off other organisms

SHAPES1. COCCI…Sphere

shaped

2. BACILLI…bar shaped

3. SPIRILLA…spiral shaped

Bactria Reproduction… Binary Fission

Bacteria reproduce in a process called BINARY FISSION

1. Cell grows larger2. DNA replicates and attaches to the cell membrane3. The DNA and its copy separate as the cell grows larger4. The cell splits in two.

* each new cell contains identical DNA

For MOST bacteria…Ideal conditions for reproduction are warm and moist.

When conditions are not ideal, some will

survive by forming and ENDOSPORE, a hard protective covering. Many bacteria can survive boiling, freezing, and extremely dry conditions. When conditions become favorable again, endospores can break open and bacteria can become active again.

Nitrogen Fixing Bacteria… takes nitrogen from the air and change it to a useable form plants can use

Decomposing Bacteria…breaks down dead matter so nutrients are available for new plants

Bioremediation…bacteria converts pollution into harmless chemicals … used to clean up wastes, oil spills and remove toxins from soils

Genetically Engineered Bacteria…To produce…

medicine, insecticides, cleaners, adhesives and some foods

Medicines such as…ANTIBIOTICS…chemicals used to kill

bacteria and other microorganisms INSULIN so diabetics are able to process

sugars and carbohydrates

Foods… (BLANK)to help make some sausage, some dairy products (cheese/yogurt/cottage cheese, etc), pickles

Pathogenic Bacteria (Cause disease)They invade the host and obtain nutrients

from the host, weakening the host and causing damage to the host

Most can be treated with ANTIBIOTICSHuman Diseases caused by Bacteria…

cavities, ear infections, strep throat, food poisoning

Can cause disease in animals but also in plants, protists, fungi and other bacteria!

Particles that imitate life…

Microscopic particle that invades a cell, often destroying it

Found everywhere Many diseases are caused by viruses Contains a protein and nucleic acid

(genetic material) DO NOT eat, grow, use air Can only reproduce with HELP from a host The are NOT living!

Viruses are classified in many ways…Type of diseaseLife cycleType of genetic materialShape

Crystal…ex: polio virus

Spherical…ex: influenza, HIV

Cylinder…ex: tobacco mosaic virus

Spacecraft…ex: bacteriophage

VIRAL REPRODUCTION Viruses MUST have a host

to reproduce The reproduction process is the LYTIC CYCLE

A. Virus finds a host

cell

B. Virus enters cell

OR DNA is injected into

cell

C. Virus’ DNA takes

over control of the cell

D. Cell produces new

viruses

E. New viruses

break out of the cell and

invade other cells

Common coldInfluenzaPolioChicken poxMeaslesMumps

Vaccines are used to build up an individual’s immunesystem by…1.Inject a weakened or “dead” virus into the body

(the shot)2. The body’s immune system recognizes the invader and

begins to build up antibodies (an army) to fight the virus3. The body’s immune system is able to build up the

antibodies to fight the virus because the virus is not very strong.

4.The next time the virus in introduced into the body, the body recognizes the virus and already has the antibodies (army) to fight the virus.

Common vaccines: polio, measles/mumps/rubella (MMR), influenza, chicken pox, hepatitis

Non-infectious Disease…a disease that is not transmitted from person to person

Infectious Disease…a disease that is caused by a pathogen (bacteria, virus, fungus, protist) can generally be transferred from person to person

Microscopic organismsFound commonly in pond waterCause dysentery

Don’t drink water from Mexico

Cause fungal infectionsYeast infectionsAthletes foot