Download Bacteria and Viruses

Bacteria and Viruses
Life Divided into Domains
Bacteria Characteristics
•
•
•
•
•
•
•
•
•
Prokaryotic
Cell wall- can be made of peptidoglycan
Laying inside the cell wall is a _____________
Capsule is sticky and helps bacteria ________surfaces as well as
providing _-----------from the hosts immune system
Extremely small- typically around _____micrometers
Flagella- used for______________
Pilli- some bacteria have these on outer surface helps in
_____________and_____________ to surface
May be found as unicellular or ________________
Endospore- ____________________________of bacteria- forms
inside cell when conditions are too harsh for survival – consists of a
thick wall around nuclear material and a small amount of
cytoplasm. Endospores have been known to survive for 50 years or
more in this dormant state
Classification of Bacteria
Archebacteria
1. Do not have peptidoglycan in cell walls have___________instead
2. Archaea differ in the types of ________in their cell membrane.
Also, archaeal genes do not contain________.
•
•
•
Methanogens- convert _______________gas into energy
Halophiles- live in high salt ________________areas
Thermoaciophiles- live in____________ temperatures as well as
very acidic environments
EubacteriaA. have cell walls made of peptidoglycan
B . Are classified according to
1. shape
2. gram stain
3. chemistry of cell wall
4. metabolism
• Proteobacteria- includes __________fixing bacteria, live in human
and animal intestines
• Gram positive-includes strep, anthrax, and botulism bacteria
• Cyanobacteria- _________________bacteria
• Spirochetes- gram negative bacteria( Lyme disease, syphilis)
• Chlamydia-gram negative bacteria that cause Chlamydia
Classification by Shape
• Bacilli- ____shaped
• Cocci- _______shaped
• Spirilla- ______shaped
• When ______occur in chains they are called streptococci
• Grapelike clusters of cocci are called staphylococci
•
•
•
•
Proteobacteria
One of __________groups
Can live symbiotically with other organisms such as Rhizobium
which lives ____________of legumes and nitrogen fixes
Can live as _____________( disease causing)- such as
Agrobacterium which causes tumors in plants or Heliobacter pylori
which causes stomach ulcers
Can be ________(live in the intestines)- Escherichia coli or E.coli
Classification by Gram Staining
• Gram negative- cell walls complex and have little ___________-
appear ______under microscope after staining with red dye
• Gram Positive- have _______cells walls and much more
pepidoglycan. Appear ________because they retain their natural
purple color
–
•
•
•
•
•
Gram-Positive Bacteria
Not all of the bacteria in this group are Gram-positive. Biologists
place a few species of Gram-negative bacteria in this group
because these species are ________________to Gram-positive
bacteria.
Very large
Streptococcus
Clostridium botulinum-causes botulism
Lactobacilli- lactic acid species that makes yogurt and makes milk
sour
Bacillus anthracis- anthrax
Cyanobacteria
• Photosynthetic
• Believed to be _______________producing organisms
–
Once called________________, cyanobacteria are now known
to be bacteria because they lack a membrane-bound nucleus
and__________________.
Spirochetes
•
•
•
•
•
•
Gram _____________
Spiral
Some ________________( need oxygen)
Some anerobic
Borrelia burgdorfen-causes Lyme disease
Treponema pallidum- syphilis
Chlamydia
•
•
•
•
•
Gram______________
Chlamydia live only__________ animal cells.
Sphere(coccus) shaped
Do not have pepidoglycan
Causes Chlamydia- STD
Nutrition and Metabolism
Need a source ___________ to build organic molecules and a source
of energy
• Heterotrophic
– Photoheterotroph- uses_______ energy but gets its carbon from
other sources
– Chemoheterotroph-obtains both _______and _________from
other organisms
• Autotrophic
-Photoautotroph- uses ________and Carbon from Co2
– Chemoautotroph- extracts energy from _____________compounds and uses CO2 as carbon source
Prokaryotic Habitats
• Obligate anerobes- ________live with oxygen present ex. Tetanus
• Obligate aerobes- must have ________to live ex. Tuberculosis and
diptheria
• Faculative anerobes- can live ____________oxygen ex. E.coli
Factors that encourage bacteria growth
• 1. food
• 2.water
• 3. temperature- Psycrophilic- _________32-68F
– mesophiles-like average temperatures 68F- 104F
– Thermophiles- ________- 113 -230F
• 4. sunlight
• 5. chemicals/ fertilizers- phosphates
• 6. acidity- usually between 6.5 – 7.5
Reproduction in Bacteria
• Asexual
• Typically by Binary fission
Bacterial Recombination
•
•
•
•
The process of exchanging genetic information________
reproduction
1. conjugation- 2 bacteria bind ___________exchange genetic info
2. transformation- bacteria takes in DNA from
___________environment
3. transduction- virus obtains small part of DNA from _____bacteria
and then virus copies itself in the bacteria
Bacteria and Humans
• Benefits•
•
•
•
•
•
Necessary for production of food/such as dairy
Decay of dead organisms/recycling process
Needed for our digestion/ E.coli
Production of vinegar
Bioremediation
Nitrogen fixation- nutrients for our crops
Bacteria and Humans
• Negatives
Some bacteria are pathogens( cause disease)
• Human diseases may result from endotoxins or exotoxins
produced by bacteria or from the destruction of body tissues.
–
–
Release endotoxins- like gram negative bacteria-cause fever,
body aches, diarrhea, hemorrhages and weakness- not released
until bacteria die
–
Release exotoxins- some gram positive- bacteria release toxins
into their environment while living.
example tetanus- Clostridium tetani
–
Antibiotics and Bacteria
• Antibiotics affect bacteria by ____________their normal processes
• Produced by some fungi and bacteria
• Antibiotic resistance- the evolution of some bacteria to resist
antibiotics
– A mutation in the ______ of a single bacterium can confer
resistance to an antibiotic.
– Cells with the ________ gene have a selective advantage when
the antibiotic is present.
Bacterial Disease
– The number of certain bacterial diseases has increased because
of the increase in the number of __________ resistant bacteria,
the movement of people into previously _____________areas,
and global travel.
– Foodborne illnesses can be avoided by selecting, storing,
cooking, and __________food properly.
– Frequent hand washing in hot, ________water is also very
important.