* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Slide 1
Survey
Document related concepts
Traveler's diarrhea wikipedia , lookup
Germ theory of disease wikipedia , lookup
Horizontal gene transfer wikipedia , lookup
History of virology wikipedia , lookup
Quorum sensing wikipedia , lookup
Anaerobic infection wikipedia , lookup
Trimeric autotransporter adhesin wikipedia , lookup
Phospholipid-derived fatty acids wikipedia , lookup
Hospital-acquired infection wikipedia , lookup
Microorganism wikipedia , lookup
Human microbiota wikipedia , lookup
Triclocarban wikipedia , lookup
Marine microorganism wikipedia , lookup
Bacterial cell structure wikipedia , lookup
Transcript
The first person to see many microorganisms, including bacteria, which he called animalcules, was Anton van Leeuwenhoek (1632– 1723). Leeuwenhoek wasn’t a scientist by training, but he did learn to grind lenses very skillfully, and his small but powerful microscopes allowed him to see what no one else has ever had. Bacteria - Introduction The oldest living organisms on earth How old are bacteria fossils? Answer: About 3.5 Billion years old How many can fill squared inch of skin? Answer: 100,000 Bacteria are single-celled organisms or………..? Answer: Unicellular Can live in extremely harsh environments * Hot or cold temperatures * Very acidic Many can make their own food. What are they called? Answer: Autotrophs Two Kingdoms of Bacteria Archaebacteria “Ancient bacteria” Oldest organisms on the planet Some are close to 4 BYO Many live in extreme environments * Hot springs * Intestines of animals * Extremely salty waters Eubacteria Do not live in extreme environments Most are harmless even helpful Many are autotrophs which is………….? Answer: * Make their own food * Photosynthesize * Help make Oxygen What are the 3 basic shapes of bacteria? 1. Bacilli : Rods or sticks 2. Cocci: Spherical or round 3. Spirilla: Squiggly called spirochetes Sizes of bacteria: From 1.5 um to 750 um or? Answer: Micrometer Bacteria Some bacteria are Autotrophs: a. How do they make their own food? By Photosynthesis Other bacteria are Heterotrophs…………..? a. Can’t make their own food b. Saprophytes – use dead organism for food How do Bacteria reproduce? Asexual reproduction called Fission: One bacterium splits into two identical bacteria 8 Major Structures of Bacteria • Capsule • Cell wall • Cell membrane • Ribosomes • Nucleoid Cell Membrane • Flagella • Pili or Cilia • Cytoplasm 7 8 Major Structures of Bacteria 1) Capsule Keeps the cell from drying out and helps it stick to food or other cells 8 8 Major Structures of Bacteria 2) Cell wall Outermost covering that maintains the overall shape of the bacterial cell 9 8 Major Structures of Bacteria 3) Cell Membrane Inner layer allows only certain things to enter and leave the bacteria 10 8 Major Structures of Bacteria 4) Ribosomes Make proteins and give the cytoplasm a granular appearance 11 8 Major Structures of Bacteria 5) DNA Genetic material of the bacterium Why is this structure NOT called the nucleus? Answer: No Nuclear membrane 12 8 Major Structures of Bacteria 6) Flagella A whip like tail some bacteria have used for movement 13 8 Major Structures of Bacteria 7) Pili or Cilia Allows bacteria to stick to things or move 14 8 Major Structures of Bacteria 8) Cytoplasm Clear, jelly-like material that makes up most of the bacterium 15 Structures of Bacteria Why are bacteria 1. Simplest form of organisms Prokaryotes? 2. The only organelles present are the ribosomes What is the function of Ribosomes? Answer: “ Factories where proteins are made” 3. No actual nucleus present Can live in harsh environments Joseph Lister In the 1860s, a British surgeon named Joseph Lister hypothesized that microorganisms caused infections. To test his hypothesis, Lister washed his hands and surgical instruments with carbolic acid, a chemical that kills microorganisms, before performing an operation. After the surgery, he covered the patients' wounds with bandages dipped in carbolic acid. Only 15 % of his patients died from infection, compared to 45 % who died before. Louis Pasteur In the 1860s, a French scientist named Louis Pasteur showed that microorganisms caused certain kinds of diseases. He also showed that killing the microorganisms could prevent the spread of those diseases. How is his discovery used today? Answer: We pasteurize milk and juices What is pasteurization? Answer: Heating at high temperature to kill pathogens or harmful microorganisms Robert Koch (1843 – 1910) German bacteriologist Won the 1905 Nobel Prize in physiology or medicine Koch proved that infectious diseases were caused by microorganisms Developed techniques for isolating and identifying disease-causing bacteria. Known as the Father of Modern Bacteriology Pathogenic Bacteria a. What do these bacteria cause? Answer: Diseases b. Only small percentage of all bacteria c. How are they treated? Answer: With Antibiotics d. Some produce poisonous substance called Toxin * Botulism in canned foods * Tetanus found in dirt * The toxins produced are one of the deadliest know to man e. What are Endospores? * Thick wall produced by bacteria when conditions are unfavorable * How long can endospores last? For hundreds of years Streptococcus aureus This type of bacteria is commonly found in the human body. It causes illnesses such as strep throat, scarlet fever, and pneumonia. What is it? Bacillus anthracis Anthrax is a serious disease caused by a bacterium. A cluster of anthrax bacteria, in red, is shown inside a blood vessel of a human lung. What is the name of the bacteria that causes anthrax? Staphylococcus aureus bacteria colony Is it harmful or pathogenic? * YES!! What illnesses does it cause? * Food poisoning * Toxic shock syndrome * Skin and wound infections causing pimples How is it treated? * With antibiotics, BUT…….. This MRSA or Methicillin Resistant Staphylococcus aureus causes serious infections in hospitals How the Body Fights Bacteria Some bacteria can cause infections. The body produces cells that defend against infection by attacking bacteria. One of these types of cells, is shown in yellow. Can you name this cell? Macrophage Macrophage This macrophage is a large, mature phagocyte or white blood cell that can ingest and destroy pathogens, foreign particles, and cancerous or diseased cells. Macrophage means “Large eater”. This macrophage is digesting a bacteria called E. coli. Do you know where in our bodies E. coli lives? Large intestine Why are they called non-pathogenic? Non* Because they do not cause diseases! Pathogenic Bacteria 1 . Help in the production of food: * Yogurt * Cheese * Sour cream 2. What do some bacteria in the large intestine produce? * Vitamin K which is needed for proper blood clotting 3. Some bacteria help break down dead organisms and other matter. What are they called? * Decomposers Population Explosion Reading Graphs: What variable is being plotted on the horizontal axis? What is being plotted on the vertical axis? Horizontal axis–time (minutes) Vertical axis–number of bacterial cells. Population Explosion Interpreting Data: According to the graph, how many cells are there after 20 minutes? 1 hour? 2 hours? 8 cells after one hour; 2 cells after 20 minutes; 64 cells after two hours. Review Questions 1. Question: Which scientist is called “The Father of Modern Bacteriology”? Answer: Robert Koch 2. Question: What is a “Pathogenic bacteria”? Answer: A bacteria that causes diseases!! 3. Question: What does MRSA stand for? Answer: Methicillin Resistant Staphylococcus Aureus 4. Question: What is the French scientist Louis Pasteur know for? Answer: He showed microorganism caused diseases and killing them would prevent the spread of those diseases 5. Question: What is a “macrophage”? Answer: A type of white blood cell that can digest bacteria, other invaders and cancer cells 6. Question: What are the 3 common shapes of bacteria? Answer: * Bacilli : Rods or sticks * Cocci: Spherical or round * Spirilla: Squiggly called spirochetes 7. Question: Why are bacteria prokaryotes? Answer: * No nuclear membrane * DNA floats around in cytoplasm * The only organelles are Ribosomes 8. Question : What are the size ranges for bacteria? Answer: 1.5 to 750 um or micrometers 9. Question: What is the difference between autotrophs and heterotrophs? Answer: Autotrophs make their own food Ex: Bacteria Plants Heterotrophs can’t make their own food Ex: Humans Animals 10. Question: How do autotrophic bacteria make their food? Answer: By photosynthesis 11. Question: True or False Most bacteria are pathogenic or disease causing? Answer: False Most bacteria are harmless, even helpful