* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Monerans / Bacteria
Survey
Document related concepts
Clostridium difficile infection wikipedia , lookup
Cyanobacteria wikipedia , lookup
Phage therapy wikipedia , lookup
Neisseria meningitidis wikipedia , lookup
Quorum sensing wikipedia , lookup
Carbapenem-resistant enterobacteriaceae wikipedia , lookup
Small intestinal bacterial overgrowth wikipedia , lookup
Anaerobic infection wikipedia , lookup
Bacteriophage wikipedia , lookup
Unique properties of hyperthermophilic archaea wikipedia , lookup
Human microbiota wikipedia , lookup
Bacterial cell structure wikipedia , lookup
Transcript
Monerans / Bacteria Smallest and simplest living organisms. IRP INFO Characteristics of Bacteria Kingdom Monera is now classified as Bacteria. They are the simplest forms of undisputed living organisms. Metabolically active, nutritional requirements, produce wastes, reproduce, can be killed. All Bacteria are classified as PROKARYOTIC. Do you remember what the characteristics of Prokaryotic cells are? Ask a friend. The characteristics are…. Prokaryotic Characteristics and Cell Structure. Unicellular Lack organelles with membranes (What’s an organelle again?) No true nucleus. Do contain chromosomes and Plasmid. Smallest cells we know of Cell structures include: cell wall, cell membrane, nucleiod region, ribosomes, flagella, cytoplasm. Basic Bacteria Diagram. Features in detail Biochemical structure of their cell walls is one of the differences which separates many of the bacteria. Walls are made of protein and carbohydrates and sometimes lipids. We use Gram’s Stain to identify these characteristics microscopically. Gram’s Stain is made of a purple and red dye. Protein/Carb will be coloured purple (Gram Positive) Lipid layers will be coloured red (Gram Negative) Continued. Many bacteria will also secrete a sticky material around their cell walls This provides some protection and holds them together to form colonies. How is a colony different than a multicelluar organism? PILI: surface chemicals that allow bacteria to join together to conduct processes. FLAGELLA: long thin protein filaments which are rotated to provide movement. This motility allows bacterial to move towards or away from stimuli. Basic Shapes. Spherical called coccus Streptococcus (strep throat) Pneumococcus (pneumonia) Rod called bacillus Escherichai Colio (E. coli) Sprial shaped called spirillus Treponema pallidium (Syphilis) Caption: colony of bacteria, Salmonella enteritidis, cause of a severe outbreak of food poisoning in Britain in 1988. The outbreak was traced to chicken eggs containing the bacteria. Caption: Serratia marcescens showing long flagella and numerous but less prominent pili. Serratia marcescens is a rod-shaped, bacterium associated with nosocomial or hospital related infections. Serratia marcescens colonize in the respiratory and urinary tracts of adults causing nosocomial bactermia, catheter-associated bacteremia, urinary tract infections and wound infections. The bacteria can also be found in the damp environment of bathrooms as a pink, slimy film that can be killed with bleach. Magnification: 30,000x Distinguishing Bacteria Three basic divisions based on their requirement of the presence or absence of oxygen. AEROBIC: Require oxygen for cellular respiration. Most bacteria fall under this category. ANAEROBIC: Thrive without Oxygen Facultative anaerobes: Typically aerobic, but have the ability to function in the absence of oxygen as well. a few notes on Aerobic and Anaerobic Cellular Respiration, (remember, the process where our cells get energy by breaking bonds in the food we eat) is considered an aerobic process. We can still metabolize nutrients in an aerobic environment though. Our muscles still work even when they don’t get enough O2, however its much less efficient. The bi-product is lactic acid which makes your muscles sore until they get enough O2 to break it down. Anaerobic process around you. There are several common processes that happen without oxygen that you are probably familiar with. 1. Our own muscles creating lactic acid but still function with an oxygen deficit. 2.Anaerobic respiration is referred to as Fermentation Used in cooking and producing alcohol. Yeast (which is actually a Fungi) are used. Additional Distinctions Once again we look at how an organism gets in nutrients. There are two divisions which we have discussed with respect to the other kingdoms. They are: Autotrophic Photosynthetic and chemosynthetic. Heterotrophic Most bacteria get their energy from the environment around them. Thinking Break From what you already know about bacteria, would you say most bacteria is positive or negative to the world around us? Is it harmful or beneficial to humans? Environmentally Helpful The vast majority of bacteria are helpful. Disease is caused by only a few of them. Water, food, and air carry bacteria from one person to another. Beneficial bacteria have also found their uses in other places. In today’s world, the environment and its related issues are steadily gaining a lot of importance. It has been seen that helpful bacteria are useful in dissolving organic sludge from water, breaking down the growth of algae, reducing the various noxious odors such as hydrogen sulfide odors, reducing ammonia levels, promoting faster growth of fish in the water body, and also defeating unhealthy bacterial growth in the water body. Personally Helpful Helpful bacteria Certain types of bacteria live in the intestines of human beings. They help in digestion and in destroying the harmful organisms. Intestinal bacteria also produce some vitamins required by the human body. Certain bacteria help break down lactose in the digestive tract. It is observed that Infants who were administered the bacteria Lactobacillus reuteri or Bifidobacterium had fewer and shorter episodes of diarrhea. Fermented milk containing the live bacteria Lactobacillus casei helps in eradicating harmful bacteria Helicobacter pylori in children. Some bacteria present on the skin protect us from the spread of certain fungus. It was found that DNA damage was significantly reduced by all six strains of lactic acid producing helpful bacteria tested with the exception of Streptococcus thermophilus. Continued. There are many types of bacteria that live inside the mouth, nose, throat, and intestines of humans and animals. These bacteria get a place to live and feed while keeping other harmful microbes from taking up residence. Certain stomach bacteria may work harmoniously with our immune system. There are billions of stomach bacteria, which are friendly or beneficial bacteria. There are some friendly bacteria such as intestinal flora or micro flora which are good for human health. These healthy stomach bacteria are helpful to release many useful vitamins such as vitamin B and vitamin K, etc. The most important task that stomach bacteria do is to maintain normal pH level or acid level of human stomach. Bacterial Reproduction We discussed the unique life cycle of a virus. Lytic and Lysogenic cycles. Review with a partner. Dependant on host cell: Debate around living organism. Most Bacteria reproduce through a process call BINARY FISSION: Specialized type of mitosis where unicellular organisms divide inorder to reproduce. Multicelled organisms use mitosis for regular growth and meiosis for sexual reproduction. Bacteria can divide as often as every 20 minutes. Do the math. How many bacteria would you have after 8 hours? Exponential Growth. This constant doubling of a population can lead to exponential growth of a bacteria. Remember exponential growth? In 1 hour there would be 8 2 hours 64 3 hours 512 4 hours 4096 5 hours 32,768 Conjugation When things are great around a bacteria and binary fission isn’t the best option, Bacteria maybe prompted to reproduce in a type of “sexual” reproduction* called CONJUGATION: DNA is replicated and transferred into another bacterial cell. The host cell can then incorporate the new genetic material into its own chromosomes. Take a minute and compare and contrast the benefits conjugation vs binary fission? *the cells will still divide in order to reproduce asexually. When times get real tough… If things get really bad for bacteria they have a last resort. Bacteria can produce an “inner cell” called an ENDOSPORE. Endospores contain a replica of the cells genetic material and stores it in a very durable cell wall. The parent cell may die, but when things get good again, the endospore may become active again and produce a new copy of the bacteria. A little bit of science history For the last several decades we have become germaphobes. Is it a chicken / Egg situation do you think? Although bacteria has been extremely beneficial to humans, some strains have of course been quiet harmful. Science has worked dilligently to create new ways to kill bacteria both inside our bodies and outside as well. Terminology You have heard the following terms used with respect to health and sterile environments but perhaps never realized their distinctions. Antibiotics Antiseptic Disinfectants All three terms are generally used interms of killing bacteria. ANTIBIOTICS: Kill bacteria inside the body. ANTISEPTICS: Kill bacteria on the surface of the body DISINFECTANTS: Kill bacterial on non-living surfaces Continued. Because bacteria are relatively simple organisms who multiply quickly and often, the chance for a mutation to happen and spread is very common. These MUTATIONS or genetic typos create new strains of the bacteria. This is very evident with respect to the medical community and you may have heard the term Antibiotic resistant bacteria. One season Antibiotics may be very effective against a bacterium, however not all are killed. Those possessing genetics which allow them to survive an antibiotic or which have mutated so antibiotics are no longer effective may now reproduce and new antibiotics must be created. Ecological Roles of Bacteria ECOLOGICAL ROLE: how bacteria affect or interact with other organisms. As we have discussed not all bacteria is bad, even some of the ones we think of as harmful serve an important purpose. E. coli as a symbiotic relationship… Hog wash! What is our current perception of E. colio? When E. coli remain in the large intestines where they belong they actually produce vitamin K and minerals for mammals to absorb as they break down fecal matter. BiWinning! Loose Ends Not all bacteria depend on another living organisms. Some are FREE-LIVING. Bacteria can be DECOMPOSERS like fungi and worms and serve an extremely important role in freeing the locked up chemical elements and nutrients of organic remains and organisms. NITRIFYING BACTERIA actually take Nitrogen out of the air and put it into a usable state for plants so that it can be put back into the food chain. Nitrogen is required by all living organisms to create proteins and nucleic acids. A quick note on Biotechnology Because of bacteria’s unique properties: Simple, asexual reproduction, basic genetic material and ability to produce proteins (unlike viruses) Science is becoming increasing aware of the benefits that bacteria can serve. Through a processes called RECOMBINANT DNA scientists can insert desired DNA into a bacteria in order to turn them into mini factories! Insulin is produced in this fashion. Videos….finally. Oil Eating Bacteria? http://video.foxnews.com/v/4273359/oil-eatingmicrobes http://www.youtube.com/watch?v=mDkCqmv2GVU &feature=related