The Grand Prismatic Spring in Yellowstone National Park is the largest hot spring in the United States The vivid colors in the spring are the result of pigmented bacteria in the microbial mats that grow around the edges of the mineral-rich water
Unit 6: Bacteria and Viruses Objective:
Do Now. Write down what you know about bacteria and viruses Bacteria Viruses
Bacteria are: Unicellular Divided into Two distinct groups Eubacteria Archaebacteria Prokaryotic which means? What is the structure? able to Reproduce (2 ways) Binary Fission Conjunction Both good and bad Most can be treated with Antibiotics Fact: Each square centimeter of your skin averages about 100,000 bacteria. A single teaspoon of topsoil contains more than a billion (1,000,000,000) bacteria.
Two kingdoms of bacteria: Eubacteria true bacteria, live almost everywhere (fresh water, salt water, land, in the human body) Archaebacteria oldest organisms on earth, live in extreme conditions (like hot springs, anoxic environments like thick mud)
Prokaryotic vs. Eukaryotic Make a list of the similarities and differences Prokaryotic Both Eukaryotic
Bacterial Structure Microscopic unicellular prokaryotes No nucleus or membrane-bound organelles Contain ribosomes a singular, circular piece of DNA (nucleiod) Have a flagella that allows them to move Some have a gelatinous layer called a capsule surrounding the cell wall pili (short, thicker outgrowths that help cell to attach to surfaces
Three bacterial shapes: Rod shaped are called bacilli Sphere shaped are called cocci Spiral shaped are called spirilla
Reproduction: Binary Fission Bacteria can reproduce asexually (mitosis) using binary fission. Single chromosome replicates & then cell divides All new cells identical (clones)
Reproduction: Conjunction Bacteria can reproduce sexually using conjugation. Bacteria exchange plasmid DNA through a tube. New cells NOT identical Can cause antibiotic resistance
Bacteria can also be categorized based on the way in which bacteria can obtain energy: heterotrophs must take in food for energy photoautotrophs - These are autotrophs that use the sun s energy to make food. Example: Cyanobacteria chemoautotrophs make energy from chemical reactions involving hydrogen sulfide, sulfur, and nitrates. Do not require the sun. example: bacteria near hydrothermal vents
ARE ALL BACTERIA BAD???? The good, the bad, and the evil! Can you think of examples of good bacteria? What about bad bacteria?
Some Good Bacteria Bacteria are vital to maintaining the living world. Some are producers that capture energy by photosynthesis. Others are decomposers that break down the nutrients in the dead matter and the atmosphere. Some bacteria are used in humans.
Decomposers Obtain energy by breaking down the chemical elements inside other living or dead organisms. Some bacteria live in the intestines of humans and animals. Wastewater bacteria feed on everything from solid human waste matter to last night's leftovers. Help the ecosystem recycle nutrients
Nitrogen-fixing bacteria (Rhizobium) Found in nodules of soybeans, peanuts, alfalfa, and clover Plants need nitrogen to make amino acids(a macromolecule), which is a building block of protein Convert atmospheric nitrogen (N 2 ) into ammonia (a form that plants can use), is called nitrogen fixation. Used in crop rotation
Human Uses Produce food, such as cheese and yogurt (lactic acid fermentation) Healthy intestinal bacteria Used to make medicine Bacteria that ingests petroleum can be used to help clean up a oil spill
Pathogens-disease causing (not good bacteria!) Called germs or bugs Cause disease Two ways in which bacteria cause disease: 1. Destroy living cells/tissues Tuberculosis destroys lung cells 2. Produce toxins (poisons) that interfere with cell functions Strep Throat, releases toxins into bloodstream and causes a scarlet fever
How is bacteria spread? Bacteria can be moved by air and water currents, and on any surface such as clothing, hands, or any object.
Bacteria Diseases
Pathogens Strep throat Streptococcus Staphylococcus
Prevention Methods Antibiotics Vaccines Sanitation Sterilization Disinfection Staying Healthy Food Storage Education
ANTIBIOTIC: A chemical that inhibits the growth of bacteria How do they work? Destroy the cell membrane /wall of the bacteria cell Interfere with the bacteria cell s chemical processes Change the DNA of the bacteria ( can t reproduce) Antibiotics cannot treat viral infections
WHAT IS ANTIBACTERIAL RESISTANCE??? Misuse and overuse of these drugs, however, have contributed to a phenomenon known as antibiotic resistance. This resistance develops when potentially harmful bacteria change in a way that reduces or eliminates the effectiveness of antibiotics When antibiotics don't work, the result can be longer illnesses more complicated illnesses more doctor visits the use of stronger and more expensive drugs more deaths caused by bacterial infections
Vaccines Many bacterial diseases can be prevented by vaccines A vaccine is a preparation of weakened or killed pathogens. The vaccines helps you body produce antibodies to fight the disease.
Sanitation and Healthy Sterilization Living Using high heat to destroy bacteria. (i.e. surgical instruments) Disinfection Chemical solution that kill bacteria (i.e. cleaners) Overuse of antibacterial soaps may increase bacterial resistance. Wash You Hands and take care of yourself!!! - Need I say more!
Food Storage and Processing Bacteria can cause food to spoil, prevention methods should be used. Refrigerate food to slow down bacterial growth Cook food to recommended temperatures to kill bacteria
Education Q: Why do you think education is important part of preventing the spread of disease?