Structures and Arrangement

Compare the two bacterial kingdoms. ArchaebacteriaEubacteria Cell Type prokaryote DNA Single loop of DNA; plasmid Environment Extreme environmentsTypical conditions Miscellaneous Closely related to eukaryotes Divided in two

Where are archaebacteria found? Geysers Nuclear Reactors Volcanoes Ocean Floor Vents Intestines of Cows

1. Gram (+) Positive Eubacteria  Have a thick layer of peptidoglycan  Purple when stained  Antibiotic used to treat: Penicillin 2. Gram (-) Negative Eubacteria  Have a thin layer of peptidoglycan  Pink when stained  Antibiotic used to treat: Tetracycline Peptidoglycan – compound found on cell walls of bacteria; made of sugars and aminoacids

1 Plasmids – small rings of DNA external to “chromosomal DNA”  Can easily pass traits such as antibiotic resistance from cell to cell  Used in genetic engineering 2 Flagella – protein fiber used for movement 3 Pili – thick, short cell outgrowth (think hair)  Aids in attachment and reproduction

Ribosome DNA Cell wall Cell membrane

SHAPEBacillusCoccusSpirillum ExampleRod shapedsphericalspiral

ArrangementDiplo-Strepto-Staphylo- ExampleCells form pairs Cells form chains Cells form clumps

Anthrax Bacillus anthracis

Food Poisoning Bacillus cereus

Diarrhea, urinary tract infections Escherichia coli

Staphylococcus aureus Staphylococcus Aureus (Staph), is a bacteria commonly found in the nose, mouth, rectum or genital area. The bacteria are harmless until they enter the body through a cut, scrape or other break in the skin. Staphylococcus Aureus infections can invade and attack any part of your body, from your skin, eyes and nails to the inner lining of your heart.

Four ways to Identify bacteria – shape – cell wall structure – how they move_ – how they obtain energy

4 Types of Metabolism METABOLIC TYPE PhototrophicReceives energy from sun Chemoautotrophic Receives energy from oxidizing inorganic molecules such as sulfur or nitrogen; found in ocean vents Heterotrophic Absorbs energy molecules made by other organisms Photoheterotroph Organism that captures sunlight for energy & also needs organic molecules as a carbon source

Anaerobic vs Aerobic Anaerobic – bacteria does not need oxygen to survive – Tetanus Bacteria Aerobic – bacteria needs oxygen to survive – Mycobacterium tuberculosis

Reproduction Binary Fission (asexual) – DNA is replicated – One cell divides into two news cells with each cell containing a copy of the DNA Conjugation (sexual) – Cells swap genetic material using palsmids – A pilus is used to transfer DNA (genetic material) from one cell to another

30 minutes Scientists love to use this in biotechnology!!

Endospores An endospore is a dormant, tough, and temporarily non-reproductive structure produced by certain bacteria to survive during periods of: – Drought – Extreme Heat – radiation

How does bacteria enter body Through air - breathing Food and water intake Body openings – nostrils, mouth, ears, cuts, etc

Food storage and Control 1.Refrigeration Slows growth of bacteria Bacteria prefer warm moist and dark habitats 2.Drying Bacteria need water to grow; therefore without moisture they cannot grow and reproduce 3.Heat Cooking food destroys bacteria. However, if left out for substantial amount of time bacteria can begin to grow 4.Canning Heat food until all bacteria is killed and sealing the container to prevent introduction of bacteria.

How do bacteria cause disease? 1. Damage the cells and tissues by using cells for food Example: Tuberculosis caused by Mycobacterium tuberculosis 2. Release toxins (poisons) that travel throughout the body Example: Strep throat (leads to scarlet fever) caused by Streptococcus pyogenes Diptheria – Corynebacterium diptheriae (can lead to death)

How can we prevent bacterial disease? 1. Vaccine – preparation of weakened or killed pathogen -prompts the body to produce immunity to the pathogen (bacteria/virus) 2. Antibiotics – block the growth and reproduction of bacteria

Ways to kill bacteria A chemical solution that kills pathogenic bacteria is called a disinfectant Sterilization - destroying bacteria by subjecting them to great heat

How is bacteria helpful? 1. Nitrogen fixers – some remove nitrogen gas from the atmosphere and change it into a form plants use 2. Decomposers 2. Human uses:  Inhabit our large intestine (colan) E.Coli – make vitamins  Used to help make foods such as – yogurt, cheese, cottage cheese, butter milk, sour cream  Digest petroleum – clean-up of oil spills  Synthesize medicines & chemicals (genetic engineering) creating insulin and other hormones