Viruses and Bacteria

Viruses Non-living biological particle composed of a nucleic acid and a protein covering Characteristics Structure VERY VERY small - Capsid- protein coat No cell parts/cell functions - Genetic material- can be DNA or RNA Reproduce only with the use of living cells THEY ARE ZOMBIES!!!

The Structure Of a Virus Viruses are composed of a core of nucleic acid The Nucleic acid core is surrounded by a protein coat called a capsid The Nucleic core is either made up of DNA or RNA but never both

Viral Types DNA RNA Retrovirus Starts out as RNA switches to DNA and then switches back to RNA (exp HIV)

HIV (human immunodeficiency virus) causes AIDS (acquired immune deficiency syndrome) The virus consists of an RNA genome, surrounded protein coat. This virus uses reverse transcriptase to make the host cell make the virus DNA

Cycle of Lytic and Lysogenic pg 200 in text

E. Coli and the Bacteriophage What it looks like in real life

How does a Vaccine Work? Prepare the body to detect and battle a virus if it comes A weakened or “dead” pathogen is introduced into the bloodstream Antibodies are formed and the body develops immunity to the particular pathogen. Antibody: protein that will recognize and fight off invaders. (finds and puts a hit out on microbes. Think Al Capone of the immune system.)

The white blob is a white blood cell and the yellow Y shapes are antibodies tagging the green bacteria for destruction.

Amoeba Sisters video https://www. youtube. com/watch Amoeba Sisters video https://www.youtube.com/watch?v=PHp6iYDi9ko How viruses work https://www.youtube.com/watch?v=Rpj0emEGShQ

Ebola Exposed: https://www.youtube.com/watch?v=87z-lxTvnBU

Bacteria

Bacterial Evolution & Classification Characteristics Microscopic Prokaryotes Oldest fossils (3.5 billion yrs) Live in nearly every environment Classification Few morphological differences 2 Kingdoms 1- Archaebacteria 2- Eubacteria

1- Archaebacteria - unusual lipids in cell membrane - different cell wall composition - live in extreme environments Methanogens Produce Methane gas Live where there is no Oxygen (bottoms of swamps, sewage, intestines Extreme Halophiles - Salty environments Thermoacidophiles Acidic Environments (pH 2) High Temps – 110 C (Volcanic vents)

2- Eubacteria (this is what your mother calls germs) Shapes Coccus = round Bacillus = rod Spirillum = spiral Strepto = chain Staphylo = cluster Ex- Staphylococcus = cluster of round-shaped bacteria

Biology of Bacteria Structure Cell wall made of Peptidoglycans (carbs and amino acids) Gram negative has an outer membrane of lipids & sugar, which give protection against antibiotics Cell membrane- lipid bi-layer

Gram Stain- lab technique used to dye bacteria 1- Gram Positive bacteria -stains Purple - used to make yogurt, buttermilk and pickles (yum) - causes human diseases (Scarlet Fever, Toxic Shock Syndrome and Pneumonia) 2- Gram Negative bacteria - stains Pink - has a lipid bi-layer that prevent antibiotics from entering (different antibiotics must be used)

Bacteria Reproduction Binary Fission Conjugation Spore Formation

Cellular organism copies it’s genetic information then splits into two identical daughter cells

Conjugation A type of Bacteria Sex Two organism swap genetic information, that contains the information such as a resistance to penicillin

Spore Formation: Endospore A type of dormant cell Exhibit no signs of life Highly resistant to environmental stresses such as: -High temperatures -Irradiation -Strong acids -Disinfectants formed in response to environmental signals that indicate a limiting factor for growth, such as exhaustion of an essential nutrient.

Antibiotics- chemicals that inhibit the growth of some bacteria Antibiotics- chemicals that inhibit the growth of some bacteria Ex-Penicillin (produced by fungus) Useful Bacteria Decomposers (breakdown dead plant & animal waste) Food processing (Yogurt, Sour Cream, Sauerkraut, Pickles, Cottage Cheese, Buttermilk) Insecticides Organic chemicals & fuels Environmental clean up (Chemical & Oil Spills)

Bacteria & Humans Pathogen- any organism that causes a disease - pathogenic bacteria enter the body through the respiratory/gastrointestinal tract - disease caused by toxins produced by bacteria Toxin- poisonous substance that disrupts the metabolism of the infected organism Endotoxin- found in the cell wall (mostly Gram -) Symptoms- fever, weakness & damage to CNS Ex- E. Coli Exotoxin- produced by Gram + & then go to surrounding environment Ex- Tetanus (Ever cut yourself or step on a nail?)