Bacteria 175 3/16/2015 Starter: Watch Video How was the virus able to enter the cell? How are viruses able to reproduce? If you breathe in the flu virus, will you automatically become sick? What are some other viruses you know about? Are viruses alive? Can medications be used against viruses? Practice: Notes Bacteria 176 3/16/2015 Application/Connection/Exit: Ws Starter • Watch and answer questions: • http://www.schooltube.com/video/08aae2e f0da979dbbb5a/Flu-Attack-How-A-VirusInvades-Your-Body March 16, 2015 AGENDA B. 8 A B.8A Define taxonomy and recognize the importance of a standardized taxonomic system to the scientific community while reading and writing by completing notes and a ws •1 Starter •2. Notes •3. Worksheet Table of Contents Date Lecture/ Activity/ Lab 2/12 Ordering Fossils Activity 2/13 Evidence of Fossils 2/17 Test Review 2/19-20 Classification 2/23 Dichotomous Key Notes 2/24 Dichotomous Key Project 3/5 Cladagrams 3/16 Bacteria, Viruses, and Protista Page 161-162 163-164 165-166 167-168 169-170 171-172 173-174 175-176 Bacteria, Viruses, Prions, and Protists Bacteria • Unicellular or Multicellular? • Prokaryotic or Eukaryotic? • Cells Walls? Bacteria • Unicellular • Prokaryotes • Cells walls containing peptidoglycan Bacteria • Extremely Abundant – Cover nearly every square centimeter of Earth What are the differences between eubacteria and archaebacteria? Eubacteria versus Archaebacteria • Cell walls of Eubacteria have peptidoglycans while those of Archaebacteria do not. • DNA sequences of archaebacteria is more similar to that of eukaryotes than to the DNA of eubacteria • Archaebacteria often live in very extreme environments (hot springs, digestive tracts, Great Salt Lake, etc.) Bacterial Shapes • Bacilli: rod shaped • Cocci: spherical • Spirilla: spiral, corkscrew Cell Walls • Gram positive: stain violet due to thick peptidoglycan walls • Gram negative: stain pink/red, have much thinner walls inside lipid layer Metabolism Heterotrophs: • Chemoheterotrophs: must take in organic molecules and a supply of carbon • Photoheterotrophs: are photosynthetic but also need to take in organic molecules for carbon source Metabolism • Photoautotrophs: use light energy to make carbon compounds • Chemoautotrophs: use energy from chemical reactions to make carbon compounds • Where might each type of bacteria be found? Binary Fission • When a bacteria grows so that it has doubled in size, it replicates its DNA and divides in half • Is this sexual or asexual? • Identical or different daughter cells? Conjugation • Some bacteria are able to exchange genetic information • A hollow bridge forms between two bacteria and genes move from one cell to the other • Increases genetic diversity of a population Conjugation Spore Formation • Spores are formed when the bacteria produces a thick internal wall that encloses the DNA and part of the cytoplasm • Why do you think this would be beneficial for bacteria? Spore Formation • Occurs when conditions are unfavorable for growth • Can remain dormant for years until conditions improve Spore Formation What are some benefits of bacteria? Benefits of Bacteria • Some are producers that undergo photosynthesis • Some are decomposers that break down dead matter to recycle the nutrients • Some convert nitrogen gas to a form that can be used by plants (nitrogen fixation) What are some dangers of bacteria? Dangers of Bacteria • Break down cells and tissues for food Example: Tuberculosis (destroys lung tissue) • Release toxins (poisons) that travel through the body Example: Streptococcus releases toxins into the blood stream causes strep throat and scarlet fever Vaccines • A vaccine is a preparation of weakened or killed pathogens that are injected into the body • This stimulates the body to produce immunity to the disease Vaccines • Why do you think we don’t vaccinate everyone for all disease we have created vaccines for? Antibiotics • Antibiotics block the growth and reproduction of bacteria • Used to treat bacterial infections Solve the Problem • What would you do to find out what causes the tobacco leaves to be diseased? Viruses • A virus is a core of DNA or RNA surrounded by a protein coat (capsid) Viruses • They can only reproduce by infecting living cells • They enter a cell and use its cell machinery to produce more viruses Retroviruses • Contain RNA as genetic information instead of DNA Would you consider viruses living? Are Viruses Living? • Cannot reproduce alone, must have a host cell • Do not undergo growth or development • Do not obtain or use energy • Evolve Prions • Diseases such as Scrapie (in sheep) and Mad Cow Disease are not caused by bacteria or viruses. What could cause them? Prions • Contain only protein • Cause disease by forming protein clumps which then induce normal proteins to become Prions • The build up eventually damages nerve tissue Protists • Domain? • Kingdom? • Prokaryotic or Eukaryotic? Protists • Domain: Eukarya • Kingdom: Protists • Eukaryotic Protists • Protists are defined by what they are not. Protists are eukaryotes that are not animals, plants, or fungi. They were the first eukaryotic organisms on earth. Types of Protists • Animal-Like Protists: heterotrophs • Plant-Like Protists: produce food through photosynthesis • Fungus-Like Protists: obtain food by external digestion Animal-Like Protists • Heterotrophs cilliate sporozoan zooflagellate Sarcodine (amoeba) Animal-Like Protists • Malaria • African Sleeping Sickness Plant-Like Protists • Carry out photosynthesis Fungus-Like Protists • Grow in damp, nutrient rich environments • Absorb food through cell membranes Bacteria 175 3/16/2015 Starter: Watch Video How was the virus able to enter the cell? How are viruses able to reproduce? If you breathe in the flu virus, will you automatically become sick? What are some other viruses you know about? Are viruses alive? Can medications be used against viruses? Practice: Notes Bacteria 176 3/16/2015 Application/Connection/Exit: Ws