BACTERIA & VIRUSES. BACTERIA PROKARYOTIC in 2 of 3 Domains 1. Eubacteria 2. Archaebacteria.
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Transcript of BACTERIA & VIRUSES. BACTERIA PROKARYOTIC in 2 of 3 Domains 1. Eubacteria 2. Archaebacteria.
BACTERIA
PROKARYOTIC in 2 of 3
Domains1. Eubacteria2. Archaebacteria
EUBACTERIAARCHAEBACTERIA
LARGERMORE VARIETIESCELL WALL
CONTAINS PEPTIDOGLYCAN
SOME HAVE DOUBLE CELL MEMBRANE
NO PEPTIDOGLYCAN
MEMBRANE LIPIDS DIFFERENT
SOME DNA SEQUENCES MORE SIMILAR TO EUKARYOTIC CELLS THAN TO EUBACTERIA
Identification
SHAPE
CELL WALL COMPOSITION
MOTILITY
METHOD OF OBTAINING ENERGY
PROKARYOTES
EUBACTERIA
CYANOTROPHIC
HETEROTROPHIC
ARCHAEBACTERIA
HELIOTROPHS
THERMOTROPHS
METHANOGENS
SHAPES
1. BACILLI
1. RODS
2. COCCI
1. BALLS
3. SPIRILLA
1. CORK-SCREW
Anaerobes Aerobes
I. ObligateI. Cannot tolerate
oxygenII. Faculative
I. +/- oxygen
Obligate Oxygen required
Oxygen Tolerance
Binary Fission
asexual reproduction
trigger: growth reaches 2x
http://www.classzone.com/books/hs/ca/sc/bio_07/animated_biology/bio_ch05_0149_ab_fission.html
Growth & Reproduction
Conjugation
Exchange of DNA thru hollow bridge that forms between 2 bacteria
Increases genetic diversity
http://highered.mcgraw-hill.com/sites/dl/free/0072835125/126997/animation6.html
Growth & Reproduction
Endospore Formation
Used when environmental conditions unfavorable
Dormancy can last years
Growth & Reproduction
Importance of Bacteria
1. DECOMPOSERS2. NITROGEN FIXERS3. INDUSTRIAL USES4. SYMBIOSIS in HUMANS
TRANSFORMATION of BACTERIA
During transformation a cell takes in DNA from outside the cell becoming a permanent component of the cell’s genome.
PLASMIDS
SMALL CIRCULAR PIECE OF DNA
NATURALLY FOUND IN SOME BACTERIA
CONTAINS DNA THAT PROMOTES REPLICATION
HAS GENETIC MARKER
PLANTS ANIMALS
CAN REMOVE CELL WALL & CELL MAY SPONTANEOUSLY TAKE UP FOREIGN DNA
OR INJECT PLASMIDS INTO CYTOPLASM
GENES CAN BE REPLACED
EUKARYOTIC CELL TRANSFORMATION
Pathogens
disease-causing agents
Bacterial Infections
Louis Pasteur 1st to prove bacteria can cause disease
bacteria produce illness in 1 of 2 ways:1. directly damage host cells or tissues2. release toxins (poisons) that then circulate
throughout body interrupting homeostasis
Preventing Bacterial Disease
vaccines: preparation of killed or weakened pathogens that prompts the immune system of the organism to produce immunity to the disease should they ever come in contact with it
Treating Bacterial Infections
antibiotics: compounds that block reproduction of bacteria or kill them
availability of antibiotics (since ~WWII) has been 1 of major reasons life expectancy increased dramatically during the 20th century
Controlling Bacterial Growth
heat sterilization: destroys bacteria by heating equipment used on patients to ~ 125 ◦C using either moist heat or dry heat
disinfectants: chemical solutions that kill bacteria, overuse in homes (antibacterial soaps) increase chance of resistance
food processing: food stored @ lower temperatures stays fresher longer because it decreases the bacterial reproductive rate; cooking food before consumption also kills bacteria
VIRUSES
NON-LIVING MADE OF A PROTEIN COAT (CAPSID) SURROUNDING NUCLEIC ACID
Bacteriophage Tobacco Mosaic Virus
Influenza Virus Rhinovirus
Lytic LysogenicCell infected with 1
virusTakes over host cell
metabolismMake many copies of
nucleic acid & capsids assemble
Cell bursts (lysis) releasing many copies of virus
Cell infected with 1 virus
Its DNA inserts into bacteria’s loop of DNA
Replicates as that cell goes through cell division
2 Types Viral Infection
Animations
http://www.bio-alive.com/animations/virology.htm
Viral Disease in Humans
viruses make you sick by disrupting homeostasis in tissues and cells of your body
viruses cannot be treated with antibioticsbest protection is prevention
Vaccines : measles, mumps, chicken pox, influenza, HPV
treatment: once sick symptoms treated often with OTC products, some anti-viral meds available
Viral Diseases in Animals
viruses produce serious animal diseaseexamples: hoof-and-mouth (or foot-and-
mouth), BPV, swine flu, bird flu
Viral Disease in Plants
threat to agricultural plantsbecause plant cells surrounded by a cell wall
the plant viruses have a more difficult time infecting cells
many plant viruses have adaptations that allow them to enter damaged cells (small tear in a leaf means some cells damaged)
VIRUSES / CELLS
COPY FIGURE 19-11 FROM PAGE 483 OF BOOK ONTO PAGE 113 of notebook
Draw a virus and a bacteria of your choice, label their parts and write a 2 paragraph reflection on what you have learned about bacteria & viruses.