Chapter 19 Bacteria & Viruses

I. Bacteria Prokaryotes Are ________________________-lack a nucleus and have few organelles Much smaller than eukaryotes Eubacteria-larger kingdom than archaebacteria;usually have protective cell wall and determines shape

Germ Theory Discovery that microorganisms are _________________(disease causing agents) The germ theory of disease states that some diseases are caused by microorganisms. These small organisms, too small to see without magnification, invade humans, animals, and other living hosts. Their growth and reproduction within their hosts can cause a disease. Beijerinck(1897) and Stanley(1935)-led to discovery of viruses-which are not living things but affect organisms

Beijerinck(1897) and Stanley(1935)-led to discovery of viruses-which are not living things but affect organisms Bacteria were discovered much earlier

__________________________-not such a strong,if any,cell wall,DNA sequences more like eukaryotes;live in HARSH environments like hot springs or volcanic vents Archaebacteria

Identifying bacteria: Bacillus or bacilli by shape 1) rod-shaped are __________________ 2) spiral-shaped are_______________________ 3) spherical-shaped are cocci(coccus-singular) Spirillus or spirilla

by cell walls-use Gram Staining-Gram(+) have thick_______________________walls/gram(-) have thinner walls by movement-some do not move and some have flagella peptidoglycan

B. Metabolic Diversity Chemoheterotrophs photoheterotrophs _____________________-must take in organic molecules for energy and supply of Carbon-as do we _____________- Autotrophs ____________________- ______________-as those found in volcanic vents Chemoheterotrophs photoheterotrophs photoautotrophs chemoautotrophs

Releasing Energy 1) Obligate aerobes-need constant supply of O2 2) _______________________-do not need O2 3) Faculatative anerobes-can survive w/or w/o O2-example-E.coli Obligate anaerobes

C. Growth and Reproduction _________________________grows,replicates DNA and splits in half Binary fission

________________________-exchange genetic info w/ a “bridge” conjugation

Some produce_________________________, which can lie dormant and germinate spores

D. Importance of Bacteria Decomposers N-fixers-for plants Human uses-food production ;cleaning up oil spills Assist digestion

II. Viruses-particles of nucleic acids,protein and sometimes lipids

capsid Not living-reproduce only by infecting living cells Usually has a DNA or RNA core w/outer protein coat Outer protein coat called a ______________-which enable it to enter a host cell—often destroying host cell ________________________-viruses that infect bacteria bacteriophage

____________________infection-virus enters cell,makes copies ,and causes cell to burst _____________________________-virus integrates DNA into DNA of host cell,and viral genetic info replicates along w/host Lysogenic Lytic

_______________________________-contain RNA as genetic info and produce DNA copy of RNA retroviruses

III. Diseases vaccination antibiotic Bacterial Infect by damaging cells or releasing toxins Mycobacterium tuberculosis Streptococcus Cornyebacterium diptherae Anthrax Lyme’s disease Tetanus Meningitis Tooth decay prevention -_______________________preparation of weakened or killed pathogens ________________________-compounds that block the reproduction or growth of bacteria vaccination antibiotic

2)control-sterilization,heat,disinfectantants,proper food processing and storage

B. Viral Common cold Influenza Smallpox Warts AIDS Chickenpox Measles Hepatitis A,B, or C West Nile Polio

viroids ________________________________single-stranded RNA moleculesw/no capsid-attack plants ______________________-virus –like particles of protein-may cause protein clumps that induce new prions---example-Mad Cow Disease prions