1. Chapter 7 Bacteria

2. What are bacteria? Bacteria are microscopic, living cells. –live almost everywhere, even extreme environments –sphere-shaped, rod-shaped, spiral-shaped smaller than plant or animal cells prokaryotic-no membrane-bound internal structures

3. What are bacteria? –some have a capsule around the cell wall while others have an outer slime layer –many have whiplike tails called flagella –most reproduce by fission

4. What are bacteria? –can be producers or consumers most are aerobes some are anaerobes

5. What are bacteria? Bacteria are classified into two kingdoms. –Eubacteria larger of the two bacteria kingdoms consumer eubacteria are grouped by cell wall thickness cyanobacteria produce their own food and are commonly called blue-green bacteria cyanobacteria provide food and oxygen for aquatic life –bloom- may be harmful

6. What are bacteria? Bacteria are classified into two kingdoms. –Archaebacteria kingdom bacteria are often found in extreme locations and divided into groups based on where they live or how they get energy –some live in salty, acidic, or very hot environments –one anaerobic group produces methane gas

7. Bacteria in Your Life Most bacteria are helpful rather than harmful –necessary for human health many aid digestion and some produce vitamins some produce antibiotics

8. Bacteria in Your Life Bacteria help keep nature in balance –bacterial saprophytes use dead organisms as food and energy sources –nitrogen-fixing bacteria in the soil and plant roots change nitrogen from the air to a form that plants and animals can use

9. Bacteria in Your Life Bacteria can be used to clean up the environmental pollution through bioremediation –some bacteria break waste down into harmless compounds –certain bacteria can eat pollutants

10. Bacteria in Your Life Many foods are made using bacteria –used in dairy products –sauerkraut and pickles are also among foods made with bacterial help

11. Bacteria in Your Life Bacteria are used in industry –bioreactors- large, carefully controlled containers used to make medicines and many other products –methane-producing bacteria can digest waste and provide a source of fuel

12. Bacteria in Your Life Bacteria that cause disease are called bacterial pathogens –toxins are made by some bacterial pathogens –some form thick walled structures called endospores when environmental conditions are unfavorable

13. Bacteria in Your Life –pasteurization- process of limited heating, can kill most harmful bacteria in food –vaccines can prevent some bacterial infections made from damaged or dead bacterial cells enable white blood cells in the body to recognize a particular type of bacteria and attack it if it appears at a later time