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Leaving Cert Biology 3.1 Diversity of Organisms Monera (Bacteria) Leaving Cert Biology 3.1 Diversity of Organisms Monera (Bacteria) – higher level • All monera are prokaryotes (Do not have membrane -bound organelles such as nuclei, mitochondria or chloroplasts) Leaving Cert Biology 3.1 Diversity of Organisms Monera (Bacteria) • Basic structure of a Bacterium: Leaving Cert Biology 3.1 Diversity of Organisms Monera (Bacteria) • three main shapes: Leaving Cert Biology 3.1 Diversity of Organisms Tuberculosis Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Chlamydia Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Do you know.. • What the five kingdoms of living things are? • What are prokaryotes? • Which group are prokaryotes? • The structure of a bacterium? • The three different shapes of bacteria? Leaving Cert Biology 3.1 Diversity of Organisms Monera (Bacteria) Nutrition in Bacteria Autotrophic Photosynthesis Chemosynthesis Heterotrophic Parasitic Saprophytic Autotrophic Bacteria – Make their own food Leaving Cert Biology 3.1 Diversity of Organisms -Photosynthetic bacteria produce their own food using light as a source of energy e.g. Purple sulfur bacteria - Chemosynthetic bacteria produce their own food using energy gained from breaking down sulfur, nitrogen and iron compounds e.g. Nitrifying bacteria Leaving Cert Biology 3.1 Diversity of Organisms Heterotrophic Bacteria - take in food made by other organisms. - Parasitic bacteria take in food by feeding on a live host e.g. salmonella bacteria - Saprophytic bacteria take in food by feeding on dead organic matter e.g. psueudomonas. Leaving Cert Biology 3.1 Diversity of Organisms Monera (Bacteria) Nutrition in Bacteria Autotrophic Photosynthesis Chemosynthesis Heterotrophic Parasitic Saprophytic Leaving Cert Biology 3.1 Diversity of Organisms Purple sulfur bacteria Leaving Cert Biology 3.1 Diversity of Organisms Nitrifying bacteria Leaving Cert Biology 3.1 Diversity of Organisms Salmonella Leaving Cert Biology 3.1 Diversity of Organisms Pseudomonas Leaving Cert Biology 3.1 Diversity of Organisms Factors affecting the growth of bacteria Factor Temperature Oxygen pH External solution concentration Pressure on bacterium Why would this effect growth? What conditions would favour growth usually? Leaving Cert Biology 3.1 Diversity of Organisms Factors affecting the growth of bacteria Temperature – has an important influence on enzyme action. Most grow at temperatures between 20 – 40oC BUT there are exceptions! Leaving Cert Biology 3.1 Diversity of Organisms Factors affecting the growth of Bacteria 2. Oxygen concentration – Most bacteria die without oxygen because they need it to respire! Leaving Cert Biology 3.1 Diversity of Organisms Factors affecting the growth of Bacteria 3.pH – Has an important influence on enzyme action. Most bacteria survive in pH of 7-8, but some can tolerate higher or lower ranges. 4.Pressure – High pressures because it causes the cell wall to collapse. Leaving Cert Biology 3.1 Diversity of Organisms Factors affecting the growth of Bacteria 5. External solute concentration– Bacteria absorb water from their environment by osmosis so most need to live in solutions with a higher concentration of water. Bacteria that live in lower concentration of water may lose water, become dehydrated and die. Leaving Cert Biology 3.1 Diversity of Organisms What you should learn about in today’s class • Why bacteria make endospores • How bacteria reproduce Leaving Cert Biology 3.1 Diversity of Organisms Homework • Pg 229 Q15a,b (not part vi) • Learn about reproduction in bacteria Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Bacteria forming endospores • Endospores are formed in unfavourable conditions: The cell shrinks, rounds up and forms a thick wall within the original structure When conditions are favourable the spores absorb water, break their walls and reproduce by Binary fission Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Bacterial reproduction Leaving Cert Biology 3.1 Diversity of Organisms Think about it.. 1. Is it sexual reproduction or asexual reproduction? 2. Does it happen quickly or slowly? 3. If a change in DNA happens in one bacteria how would it effect daughter cells? Write out the full sentence answers to these questions under your diagram Leaving Cert Biology 3.1 Diversity of Organisms Monera (Bacteria) • Reproduction is asexual and occurs by Binary fission 1. DNA replicates 2. Cell elongates and pushes the replicated DNA apart 3. Cell membranes and cell wall grow inwards 4. Two identical cells are formed. Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Mutations in Bacteria • If there is a mutation (change in genetic material) it will be passed on very quickly to a large number of bacteria Leaving Cert Biology 3.1 Diversity of Organisms What do you know about? • What is an endospore? When is it formed? • Is bacterial reproduction asexual or sexual? • What is this type of reproduction called? • What are the main stages? • What happens if there is a mutation in a bacterium? Leaving Cert Biology 3.1 Diversity of Organisms Today’s objectives • To learn what antibiotics are Leaving Cert Biology 3.1 Diversity of Organisms Antibiotics • Some bacteria make antibiotics Def Antibiotics are chemicals made by microorganisms that stop the growth or kill microorganims. Since antibiotics do not harm humans we can use them for our own defence against pathogenic bacteria! Leaving Cert Biology 3.1 Diversity of Organisms Antibiotic resistance Some bacteria may develop a mutation in a gene and this may give them a way to fight against the antibiotic Any bacteria which do become resistant will have no competitors and will reproduce very quickly! Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Antibiotic resistance Leaving Cert Biology 3.1 Diversity of Organisms Antibiotics can be abused The overuse of antibiotics causes more antibiotic resistant bacteria to develop This often happens when antibiotics are available without prescriptions or when patients do not finish prescriptions fully! Leaving Cert Biology 3.1 Diversity of Organisms Do you know.. • • • • • What an endospore is? How reproduction in bacteria happens? How antibiotics are made? Why antibiotics are useful? How resistance to antibiotics is developed in bacteria? Leaving Cert Biology 3.1 Diversity of Organisms Pathogenic bacteria Def Microorganisms that cause disease are Pathogenic Do you know any pathogenic bacteria? Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Leaving Cert Biology 3.1 Diversity of Organisms Negative effects on the Economy Lactobacillus spoil milk which wastes money! E. Coli bacteria and Salmonella can cause food poisoning! (medical care costs!!!) Leaving Cert Biology 3.1 Diversity of Organisms Positive effects on the Economy Lactobacillus - used to make yogurt and cheese. E.Coli bacteria are genetically engineered and used to make insulin etc
