Transcript Chapter 10
Bacteria Smallest and simplest organisms on the planet Also the most abundant 1 gram of soil has over 2.5 billion bacteria Shapes of Bacteria Coccus– spherical Bacilli – rod Spirilla-spiral http://trc.ucdavis.edu/biosci10v/bis10v/week7/20f/Slide2.gif Bacteria Prokaryotes – single celled, no nucleus around their genetic material Belong to either the Archaebacteria or Eubacteria kingdoms Kingdom Archaebacteria Thrive in unusual places Salt lovers- are found where there is a high concentration of salt (the Dead Sea) Heat lovers – are found in hot springs (Yellow stone) Methane makers- are found in swamps Kingdom Eubacteria Most bacteria are eubacteria Eubacteria has more individual organisms than any other kingdom Eubacteria get food in 2 ways Most are consumers – obtaining nutrients from other organisms Decomposers – feed on dead organic matter Parasites – feed on living organisms Pseudomonas is one kind of bacteria found in the soil. Bacteria recycle dead plants and animals by turning them into minerals and nutrients that plants can use. Eubacteria that aren’t comsumers Some are producers – make their own food Some are photosynthetic these bacteria have chlorophyll and convert sun energy into food like plants Ex: Cyanobacteria Cyanobacteria Bacterial producer Live in aquatic environments Bacteria Reproduction Binary Fission- simple cell division 1. 2. 3. 4. Cell grows DNA replicates and attaches to cell membrane DNA and copy separates as the cell grows even larger Cell splits in 2. Each new cell has a copy of the DNA http://diverge.hunter.cuny.edu/~weigang/Images/06-11_binaryfission_1.jpg Most bacteria thrive and reproduce at optimal environments (the best) Warm, moist environments If the conditions are unfavorable, some species form a thick, protective membrane Once the membrane is formed the bacteria is known as an endospore Bacteria’s Role in the World Cleaning pollution up- used to combat Bioremediation- use of bacteria and other microorganisms to change pollutants in harmless chemicals Clean up industrial, agriculture wastes and oil spills Iron from acid run-off from mining can be treated on site to reduce and extract pollutants Antibiotics Medicines used to kill bacteria and other microorganisms Some bacteria have been genetically engineered to make large quantities of antibiotics Food Lactic-acid bacteria – convert sugar in milk to lactic acid which is a preservative and adds flavor Used in sour dough bread, cheese, yogurt, sour cream, sourkraut and pickles Harmful Bacteria Pathogenic diseases bacteria – cause Examples Dental cavities, ulcers, strep throat, food poisoning, bacterial pneumonia, Lyme disease, Tuberculosis, Typhoid fever