BACTERIA & VIRUSES

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

EUBACTERIA ARCHAEBACTERIA LARGER MORE VARIETIES CELL 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 PROKARYOTESEUBACTERIACYANOTROPHICHETEROTROPHICARCHAEBACTERIAHELIOTROPHSTHERMOTROPHSMETHANOGENS

SHAPES 1. BACILLI 1. RODS 2. COCCI 1. BALLS 3. SPIRILLA 1. CORK- SCREW

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

Binary Fission asexual reproduction trigger: growth reaches 2x /books/hs/ca/sc/bio_07 /animated_biology/bio_ ch05_0149_ab_fission.h tml Growth & Reproduction

Conjugation Exchange of DNA thru hollow bridge that forms between 2 bacteria Increases genetic diversity hill.com/sites/dl/free/ /126997/anima tion6.html hill.com/sites/dl/free/ /126997/anima tion6.html Growth & Reproduction

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

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

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 1 st to prove bacteria can cause disease bacteria produce illness in 1 of 2 ways: 1. directly damage host cells or tissues 2. 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 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 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 Lysogenic 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 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

LYTIC CYCLE

LYSOGENIC CYCLE

Animations

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 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.