BACTERIA VIRUSES BACTERIA PROKARYOTIC in 2 of 3

BACTERIA & VIRUSES

BACTERIA �PROKARYOTIC �in 2 of 3 Domains 1. Eubacteria 2. Archaebacteria

EUBACTERIA ARCHAEBACTERIA �LARGER �NO PEPTIDOGLYCAN �MORE VARIETIES �CELL WALL CONTAINS PEPTIDOGLYCAN �SOME HAVE DOUBLE CELL MEMBRANE �MEMBRANE LIPIDS DIFFERENT �SOME DNA SEQUENCES MORE SIMILAR TO EUKARYOTIC CELLS THAN TO EUBACTERIA

Identification CYANOTROPHIC EUBACTERIA SHAPE CELL WALL COMPOSITION HETEROTROPHIC PROKARYOTES HELIOTROPHS MOTILITY METHOD OF OBTAINING ENERGY ARCHAEBACTERIA THERMOTROPHS METHANOGENS

SHAPES 1. BACILLI 1. RODS 2. COCCI 1. BALLS 3. SPIRILLA 1. CORKSCREW

Oxygen Tolerance Anaerobes Obligate I. Cannot tolerate oxygen II. Faculative I. +/- oxygen I. Aerobes �Obligate Oxygen required

Growth & Reproduction Binary Fission �asexual reproduction �trigger: growth reaches 2 x http: //www. classzone. com /books/hs/ca/sc/bio_07 /animated_biology/bio_ ch 05_0149_ab_fission. h tml

Growth & Reproduction Conjugation �Exchange of DNA thru hollow bridge that forms between 2 bacteria �Increases genetic diversity �http: //highered. mcgrawhill. com/sites/dl/free/00 72835125/126997/anima tion 6. html

Growth & Reproduction Endospore Formation �Used when environmental conditions unfavorable �Dormancy can last years

Importance of Bacteria 1. DECOMPOSERS 2. NITROGEN FIXERS 3. INDUSTRIAL USES 4. 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

EUKARYOTIC CELL TRANSFORMATION PLANTS �CAN REMOVE CELL WALL & CELL MAY SPONTANEOUSLY TAKE UP FOREIGN DNA �OR INJECT PLASMIDS INTO CYTOPLASM ANIMALS �GENES CAN BE REPLACED

Pathogens �disease-causing agents

Bacterial Infections �Louis Pasteur 1 st to prove bacteria can cause disease �bacteria produce illness in 1 of 2 ways: directly damage host cells or tissues 2. release toxins (poisons) that then circulate throughout body interrupting homeostasis 1.

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 20 th 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

2 Types Viral Infection Lytic �Cell infected with 1 virus �Takes over host cell metabolism �Make many copies of nucleic acid & capsids assemble �Cell bursts (lysis) releasing many copies of virus Lysogenic �Cell infected with 1 virus �Its DNA inserts into bacteria’s loop of DNA �Replicates as that cell goes through cell division

LYTIC CYCLE

LYSOGENIC CYCLE

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 antibiotics �best 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 disease �examples: hoof-and-mouth (or foot-and-mouth), BPV, swine flu, bird flu

Viral Disease in Plants �threat to agricultural plants �because 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.