Microorganism Notes What is a microorganism? •A tiny living thing that can be seen only with the help of a microscope Bacteria • Are microscopic prokaryotes (a unicellular organism that does not have a nucleus or other membrane-bound organelles). • Is a single-celled organism. Bacteria • Archaea – another well-known prokaryotes. • Similar to bacteria; no membrane organelles. • Bacteria are much smaller than plant or animal cells. Bacteria • Pili (Pie-Lee)- hair like structures cover the entire surface and help the bacteria stick • Cilia-hair like structures on the surface • Flagella-tail like structure, helps move Common Shapes of Bacteria Bacteria • Bacteria reproduce asexually by fission. o Fission: is cell division that forms two genetically identical cells. o Are identical to the parent cell. Bacteria • Conjugation: happens when two bacteria of the same species attach to each other and combine their genetic material. • New organisms are not produced during this time – not considered reproduction. Bacteria • Some bacteria do not need oxygen to survive. o Anaerobic: bacteria that does not need oxygen to survive. o Aerobic: bacteria that need oxygen, Bacteria • 1. Some take in food and break it down and obtain energy. • 2. Some feed on dead organisms. • 3. Some take in nutrients from living hosts. • 4. Some make their own food. Bacteria • Yogurt/lactobacillus- helps with digestion • Medicines- vitamin K helps with blood clotting • E.Coli-prevents harmful bacteria from growing in the intestines Viruses Virus • A strand of DNA or RNA surrounded by a layer of protein that can infect and replicate in a host cell. Viruses Characteristics • Does not have a cell wall, a nucleus, or any other organelles present in cells. • Viruses are not considered to be alive o Cannot take in nutrients or use energy. o Cannot replicate by themselves. Viruses • The living cell that a virus infects is called a host cell. o 1. Latent viruses go through an inactive stage, o 2. When active, a virus takes control of the host cell and replicates. Viruses • Mutations: allows viruses to adjust to changes in their host cell. o These changes happen so fast that it is difficult to cure or prevent viral diseases before they mutate again. Viruses • Antibody: a protein that can attach to a pathogen and make it useless. • Vaccine: a mixture containing material from one or more deactivated pathogens. Protists Protists • Eukaryotic organisms: membrane-bound nucleus. • Decomposers • Can be harmful o Parasites • Malaria Plantlike Protists • 1. Plantlike Protists: • Example: Algae – plantlike protists that produce food through photosynthesis using light energy and carbon dioxide. Plantlike Protists 1. Diatoms 2. Dinoflagellates • Hard outer wall • Unicellular • Found in pond water • Has flagella • Unicellular Plantlike Protists 3. Eugleniods • Unicellular with flagellum at one end • Pellicle is the cell coat • Eaten by tadpoles and small fish • Euglena Animal-Like Protists • Protozoans – are protists that resemble tiny animals. • Unicellular • Live in wet environments. Animal-Like Protists 2. Pseudopods 1. Ciliates (Rhizopods) • Are short, hairlike • A temporary ‘foot’ that structures that grow on forms as the organisms the surface of some pushes part of the body protists. outward. Paramecium Stentor Amoeba Animal-Like Protists 3. Flagellates • Use flagella that whip through a watery environment. • Eat decaying matter. • Example: Euglena Funguslike Protists • Break down dead plant and animal matter, making the nutrients from these dead organisms available for living organisms. Fungi Fungi • Eukaryotes: membrane-bound nucleus. • Heterotrophs – cannot make their own food. • Grouped together based on how they look and how they reproduce. Types of Fungi Club Fungi • They are named for the clublike shape of their reproductive structures. • Example: Mushroom Types of Fungi Sac Fungi • Sac like shape • Named also for the reproductive structures. • Example: Yeast (bread) Types of Fungi Zygote Fungi • Grow over materials dissolving the material and absorbing nutrients. • Example: Bread mold Pictures Imperfect Fungi • Do not have a ‘perfect’ reproductive stage in their cycle. • Example: Blue cheese and athlete's foot. .