Aim: What are the characteristics of bacteria?

Bacteria Antonie van Leeuwenhoek discovered bacteria Are in the air, foods, surfaces of things we touch Found underground and at the great depths of the oceans Lives in your body Some like extreme temperatures-live in hot springs Others live in cold water, or acidic water, or salty water

Structure of Bacteria Smaller than plant or animal cells One-celled that occur alone, in chains or groups 3 basic shapes: 1. Spheres: Called cocci 2. Rods: Called bacilli 3. Spirals Called spirilla

Contains cytoplasm surrounded by cell membrane and a cell wall Prokaryotic -no membrane-bound organelles and nucleus Genetic material is located in the one circular chromosome Ribosomes found in cytoplasm

Special Features Some bacteria has a thick, gelatinlike capsule around the cell wall Helps protect the bacteria from being destroyed Helps it stick to surfaces Some have hairlike projections on its surface helps them stick to surfaces Slime layer also helps them stick Those who live in moist places have a flagella Helps them move

Aim: How do bacteria reproduce and obtain energy?

Reproduction Reproduces by fission Simplest form of asexual reproduction 2 new cells with genetic material identical to the original cell are produced Some reproduce through a process similar to sexual reproduction 2 bacteria line up next to each other Exchange DNA through a tube Results in cells with different combinations of genetic material-may give them an advantage on surviving

Obtaining Food and Energy Some make their food Contain chlorophyll and use the Sun’s energy Others use energy from chemical reactions Called producers Some get it from their environment Most are consumers Break down dead organisms Live as parasites

Aerobe-uses O2 for respiration Most bacteria are aerobes Anaerobe-is adapted to live without O2 Several kinds of this bacteria live in the digestive tract of humans Some can’t survive in areas with O2

Aim: What is the difference between Eubacteria and Archaebacteria?

Eubacteria Grouped according to their: cell shape structure way they obtain food type of food they consume Wastes they produce Method used for cell movement Whether its an aerobe or anaerobe

Some are producers Cyanobacteria Make their own food used CO2, water, and energy from the sun Produce oxygen as a waste Contain chlorophyll and a blue pigment Known as blue-green bacteria Some are yellow, black or red

live together in long chains or filaments Many covered with gelatinlike substance-able to live in colonies Are an important source of food for some organisms Can cause problems for aquatic life Some are consumers Grouped based on whether they are gram- positive or gram-negative Composition of the cell wall can determine how it will react to antibiotics

Archaebacteria Found in extreme conditions, such as hot springs One of the first organisms on Earth Grouped based on Where they live How they get energy Some live in salty environments Some live in acidic or hot environments

Some are methane producers Live in muddy swamps, intestines of cattle and humans Anaerobic Use CO2 for energy Release methane as a waste Used to breakdown sewage material

Aim: How can bacteria be helpful?

Benefits of bacteria Some bacteria is responsible for producing vitamn K- necessary for blood clotting Some help digest food in the large intestine Some produce antibiotics Bacillus produces antibiotic found in antiseptic ointments Bacterial found in the soil produces streptomycin

Some are saprophytes- help recycle nutrients Used in sewage plants to break down wastes in CO2 and H2O Nitrogen-fixing bacteria Change nitrogen in the air to forms that plants and animals can use Animals and plants need nitrogen to make proteins and nucleic acids Saves farmers millions of dollars in fertilizer

Bioremediation-using organisms to help clean up or remove environmental pollutants Uses bacteria to breakdown wastes and pollutants into simpler harmless compounds Other bacteria use certain pollutants as a food source Only 5%-10% of wastes are treated through this process Scientists researching to make it faster

Used in the production of foods Yogurt Cheeses Sauerkraut Soy sauce pickles Used to make medicines, enzymes, cleansers and adhesives Methane gas that is released by many bacteria can be collected and used as fuel

Aim: How can bacteria cause human diseases?

Harmful Bacteria Pathogens-any organism that causes disease Bacterial pathogens can cause illness and disease Enter through cut in the body, or inhale them Once in your body they multiply Some produce toxins-Ex: Botulism Some bacteria have endosperms that enable them to adapt to harsh environments

All food contains bacteria unless it was sterilized One way to kill bacteria is through pasteurization Usually treated with antibiotics Example: penicillin Vaccines can prevent bacterial diseases