Old Kingdom: MONERANS

New: Eubacteria &

Archaebacteria

Bacteria

Monerans - prokaryotic cellsDo not have a membrane-bound nucleus

• Size is 1-10 micrometers (1 micrometer is 1 thousandth of a millimeter)

• 4 Phyla (old system)

1. Eubacteria - true bacteria, surrounded by cell wall

2. Archaebacteria - live in harsh environments

3. Cyanobacteria - blue-green, photosynthetic

4. Prochlorobacteria - contain chlorophyll, like plants

Identification1. Cell shapes

Bacilli - rod shaped

Cell shape

Cocci - spherical

Cell shapeSpirilli - spiral shaped

Identification2. Cell wall - Gram

staining

Gram positive - takes in dye and is violet

Gram negative - appears red. Usually disease causing bacteria.

Chemical differences in cell wall

Identification3. Movement

– Flagella

– Lash, snake or spiral forward

– Glide along slime layer

– No movement at all

Identification4. Obtain energy

Autotrophs - can make own food

a. Phototrophic - traps sunlight

b. Chemotrophic - uses inorganic molecules

Identification

Heterotroph - cannot make own food. Takes in organic molecules, breaks down and absorbs.

Respiration• Obligate aerobes - must have

oxygen

• Obligate anaerobes - does not need oxygen– Tetanus and Clostridium botulinium

• Facultative anaerobes - with or without oxygen

Reproduction

• Binary fission - asexual cell division

• Conjugation - sexual exchange of genetic info

• Spore formation endospore- thick internal wall that encloses DNA. Grows when conditions are right.

Importance of Bacteria

A. Good Bacteria• Production of food

cheese, buttermilk, wine

• Industrial use - digest oil from spills, remove poisons from water, used to synthesize drugs.

• Symbiosis - live with other organisms.

Ex:E. coli in intestines helps absorption

• Nutrient flow - bacteria recycle & decompose dead material to return to soil

• Nitrogen fixation for plants

Importance of Bacteria

B. Bad bacteria• Pathogenic -

disease causing– Diphtheria,

tuberculosis, typhoid fever, tetanus, syphilis, cholera & bubonic plague

Controlling bacteria growth• Freezing - stops

growth

• Refrigeration - slows growth

• Canning - heat to boil, seals out air but some endospores will survive

Controlling bacteria growth

• Drying - no moisture

• Salt - if enough then no growth

• Radiation & alcohol - used to sterilize & kill

• Antibiotics - drugs & natural compounds that attack and destroy

Viruses

A noncellular particle made up of genetic material and protein that

can invade living cells

(a parasite needs a host)

VirusesA. Composed of DNA or RNA (not both!)

surrounded by a capsid (protein coat)

B. Not composed of cells. Infect living cells, grows, reproduces & evolves– Bacteriophage: virus that invades bacteria

C. Shapes– Rod– Tadpole– Many sided (helical or cube-like)

VirusesD. Vary in size (20 - 400 nanometers)

1 nanometer = 1 billionth of a meter

E. Viruses classifed according to host– Bacteria

– Plant viruses

– Human & other animal viruses (HIV & SIV)

F. Viruses mutate and become stronger in next generation

Lytic Virusinvade or infect a living host to

reproduce (kills host)

A. Infection/attachment - injects DNA into host cell

B. Growth - virus DNA shuts down normal cell activities to make copy of itself

C. Replication = uses materials of host to make copies

D. Cell lysis = infected cell bursts & releases new viral particles that will infect other cells

Lysogenic InfectionDoes not lyse the host

cell, it justs incorporates itself in host DNA (prophage)

Ex: Retrovirus - contains RNA. When in host cell, the genetic info is read backwards (RNA to DNA). Some cause cancer.

HIV is a retrovirus

Viral Diseases

• Chicken pox

• Cold sores

• Yellow fever

• Measles

• Common cold

• HIV

• Some forms of cancer (HPV)

Famous People

• Jonas Salk - polio vaccine

• Louis Pasteur - rabies vaccine

• Edward Jenner - small pox vaccine

Draw picture of virus and label

(DNA or RNA)

Copy and label picture of a bacteria from overhead.

The End