MICROORGANISMS CHAPTERS 24-28

Topics of Study Bacteria Viruses Protozoa Algae Fungi

Bacteria Fun Fact: There are over 2 million bacteria living on your face Fun Fact: A single bacterium can reproduce itself to produce millions of copies in just seven hours after entering the host. https://www.youtube.com/watch?v=Mj9SUJdpJS4&feature=player_embedded

Classification Bacteria fall under: Domain: Bacteria Kingdom: Archaebacteria (ancient bacteria) and Eubacteria (true bacteria) Bacteria are the most numerous as well as the oldest living organism

Classification in Eubacteria Bacteria are classified by Gram stain & based upon the presence of peptidoglycan Gram-positive Appear purple Has peptidoglycan Gram-negative Appear pink No peptidoglycan

Bacteria In general, bacteria are: Microscopic Unicellular Prokaryotes Contain no nucleus or membrane-bound organelles

Fights off bad bacteria Nitrogen fixation Decomposers Good Bacteria Bad Bacteria Digestive Bacteria Probiotics Yogurt (other foods) Fights off bad bacteria Nitrogen fixation Decomposers Symbiotic relationships Clean up oil spills Strep throat Ear infections Spoiled food Foodborne illness E. coli

Bacteria Shape Rod= Bacilli Spheres= Cocci Spirals= Spirilla Found in: Staphylo – in clusters Strepto – in chains Diplo – 2 cells

Checkpoint Who am I? Shape: __________ Found in: ________

I am…… Streptococcus and I cause strep throat

Structure Cell Wall maintains shape and form Endospore protects the cell Capsules helps evade immune system Pili help bacteria cling to surfaces Flagella is used for movement Plasmids are rings of DNA

Reproduction and Growth Some types of bacteria can reproduce every 20 minutes Transformation Takes in DNA from its external environment Conjugation (sexual reproduction) Exchange of genetic information by a protein bridge Binary Fission (asexual reproduction) Divides in half

Binary Fission is the splitting of a parent cell into two daughter cells

Conjugation

Transformation involves bacteria taking up free pieces of DNA secreted by live bacteria or released by dead bacteria. 

Human Disease Pathogen Diseases caused by bacteria: Patho = disease Gen = to make Diseases caused by bacteria: Tuberculosis Bubonic plague Syphillis/gonorrhea Cholera Lyme disease Botulism Salmonella Food poisoning Antibiotics are used to attack and destroy these bacteria

Viruses Non-living particle composed of a nucleic acid and a protein coat

Properties of Viruses Virus= poison in Latin A non-cellular particle made up of genetic material and protein that can invade living things consist of 2 major parts - a protein coat or capsid, and DNA or RNA can only reproduce inside a host cell

Properties of Viruses Extremely tiny Can’t move or grow Specific viruses infect specific organisms Plant viruses can’t infect an animal A bacteriophage is a virus that invades bacteria

Life Cycles Lytic Cycle - reproduction occurs, cells burst Lysogenic Cycle - reproduction does not immediately occur (dormancy) 

Human Diseases https://www.youtube.com/watch?v=Rpj0emEGShQ&feature=player_embedded

How do vaccines work? Vaccines are made by growing a weakened or killed form of the virus (often grown in eggs) This form of the virus is injected into a person's body, which causes an immune response, and immunity to the virus.