chapter 19 bacteria & viruses. i. bacteria are ________________________-lack a nucleus and have...
TRANSCRIPT
Chapter 19
Bacteria & Viruses
I. Bacteria
• 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
Prokaryotes
• __________________________-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:
– by shape• 1) rod-shaped are __________________• 2) spiral-shaped
are_______________________• 3) spherical-shaped are cocci(coccus-
singular)
Bacillus or bacilli
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
• Heterotrophs– _____________________-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
• 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
capsid
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
Lytic
Lysogenic
• _______________________________-contain RNA as genetic info and produce DNA copy of RNA
retroviruses
III. Diseases
• 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
– ________________________________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
viroids
prions