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EXAM UNIT ONE “Foundations”

EXAM UNIT ONE “Foundations”. INTRODUCTION TO MICROBIOLOGY CELL STRUCTURE TAXONOMY. THE STUDY OF MICROBIOLOGY. Sub-discipline of Biology Study of microscopic life forms known as microbes (Bacteria, Protozoans, Algae, & Fungi)

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EXAM UNIT ONE “Foundations”

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  1. EXAM UNIT ONE“Foundations” INTRODUCTION TO MICROBIOLOGY CELL STRUCTURE TAXONOMY

  2. THE STUDY OF MICROBIOLOGY • Sub-discipline of Biology • Study of microscopic life forms known as microbes (Bacteria, Protozoans, Algae, & Fungi) • Study of Microscopic Infectious Agents(viruses, prions, & viroids) • Microbes play a vital role in evolution, ecology, food production, industry, and public health.

  3. MICROBES & EVOLUTION • Ancient bacteria (archaeobacteria) were the first living things. • They first appeared approx. 4 billion years ago (earth is 4.7 B.Y.O). • Photosynthetic archaeobacteria oxygenated the earth and allowed all advanced life forms to evolve.

  4. Many microbes (bacteria and fungi) are decompsers (saprotrophic) and break down organic matter. Decomposers release nutrients form dead organisms and return them to the ecosystem. These free nutrients are recycled & used by other organism for growth, repair, & maintenance. MICROBES & ECOLOGY

  5. NUTRIENT CYCLING

  6. MICROBES & FOOD PRODUCTION • Microbes are widely used in food production. • Examples of microbial food products are: cheese, sour cream, yogurt, butter milk, vinegar, bread, soy sauce, beer, and wine. • Typically involves bacteria and/or yeast.

  7. Microbes are used in many industrial products and processes. Some examples are the development of medicines(clot-busting drugs, antibiotics, antiserums), the production of chemicals (alcohols, organic acids, acetone), the production of various enzymes, vitamins, hormones, steroids, and perfumes. MICROBES & INDUSTRY

  8. Russian born Jewish Microbiologist. • Devout Zionist, believed Israel was the homeland of the Jewish people. • Developed a bacterial fermentation process to make acetone that helped the British make explosives in WWI. This gave him wealth and political influence. • Became the first President of Israel.

  9. Most microbes (97%) are nonpathogenic & do not cause disease. Approximately 3% of microbes are pathogenic (disease causing). Microbes cause disease through direct infection or microbial intoxication. MICROBES & MEDICINE

  10. EARLY PIONEERS OF MICROBIOLOGY • Micros were first discovered in the mid 1600s. • It was not until the mid 1800’s that a connection was made between microbes and infectious disease. • Three early pioneers in microbiology were Anton Van Leeuwenhoek, Louis Pasteur, and Robert Koch.

  11. ANTON VAN LEEUWENHOEK(1632 – 1723)

  12. Anton Van Leeuwenhoek • Anton Van Leeuwenhoek was a merchant who built quality 200X microscopes. • He is credited with making the first recorded observations of microscopic organisms. • During his lifetime, microbes were considered mere curiosities and were not associated with disease.

  13. LOUIS PASTEUR(1822 – 1895)

  14. Louis Pasteur • Louis Pasteur was a French Chemist who first solved the mysteries of fermentation. • Pasteur was the first to prove that microbes are agents of change. • In 1857, he proposed the Germ Theory of Disease. This theory states that microbes can cause disease. • Pasteur also developed numerous vaccines.

  15. ROBERT KOCH(1843 – 1910)

  16. Robert Koch • Robert Koch was a Prussian doctor who had a great interest in the disease anthrax. • By conducting numerous experiments on mice, he developed a technique to prove that a specific bacterium was the cause of anthrax. This allowed him to prove Pasteur’s Germ Theory of Disease. • Koch’s techniques to prove the Germ Theory became known as Koch’s Postulates.

  17. Koch’s Postulates • Microbe must be present in all cases of the disease. • Microbe must be retrieved from the diseased organism and grown in pure culture. • The pure culture must be introduced to lab specimens and the disease recreated. • The microbe must be retrieved from the lab specimens and re-grown in pure culture.

  18. CELL STRUCTURE • The cell is the basic unit of life. • All living things are made of single cells, colonies of cells, or are multi-cellular. • There are 2 basic types of cells: Prokaryotic and Eukaryotic.

  19. Prokaryotic Cells • Simplest, most primitive form of cell. • First arose 4 billion years ago. • Always occur as single-celled organisms. • All bacteria are prokaryotic cells. • Do not have membrane-bound organelles or a true nucleus.

  20. Eukaryotic Cells Advanced, most complex form of cell. First arose approx. 1.5 billion years ago. Occur as single-celled organisms, colonial organisms, or multi-cellular organisms. Have membrane-bound organelles and a true nucleus.

  21. Single-Celled Eukaryotic Organisms Examples include yeasts, algae, and protozoans. Some are plant-like and some are animal-like. Some are pathogenic and cause diseases such as candidiasis and Malaria.

  22. Colonial Eukaryotic Organisms Some eukaryotic cells form colonies but don’t have true division of labor. One example is a sponge.

  23. Multi-cellular Eukaryotic Organisms Most advanced organisms. Includes fungi, plants, and animals. Have cells arranged to form tissues which form organs organized into organ systems.

  24. The Eukaryotic CellPlasma Membrane Also known as the cell membrane. Composed of a bi-layer of phospholipids with embedded proteins. Regulates the passage of molecules in and out of the cell.

  25. The Eukaryotic CellCytoplasm and Cytosol The interior of the cell is known as the cytoplasm. The fluid portion of the cytoplasm is the cytosol. Within the cytosol are specialized structures known as organelles.

  26. The Eukaryotic CellOrganelles The term “Organelle” means little organs. Organelles are specialized structures within the cell. In eukaryotic cells the organelles are associated with membranes.

  27. Eukaryotic Cellular Organelles(THE NUCLEUS) Known as the Brain of the cell. Surrounded by a double-layered membrane. A membranous sac containing DNA and protein (chromatin). Control all cellular functions.

  28. Eukaryotic Cellular Organelles (THE NUCLEOLUS) Found within the nucleus. There may be numerous nucleoli within the cell. Composed of RNA and protein. Associated with the making of proteins.

  29. The Eukaryotic CellCYTOSKELETON The ctyoskeleton provides internal support for the cell. It is composed of rods, tubes, and filaments made of protein. The cytoskeleton also aids with the movement of organelles.

  30. Eukaryotic Cellular Organelles (RIBOSOMES) Known as the “Protein Factories” Site of protein production (synthesis). Composed of ribosomal RNA and protein.

  31. Eukaryotic Cellular Organelles (ROUGH ENDOPLASMIC RETICULUM) System of membranous canals and tubules. Studded with ribosomes. Associated with the transport of proteins.

  32. Eukaryotic Cellular Organelles (SMOOTH ENDOPLASMIC RETICULUM) System of membranous canals and tubules. Does not contain ribosomes. Function varies with cell type. Removes toxins in some cells.

  33. Eukaryotic Cellular Organelles (GOLGI COMPLEX) Also known as the “Post Office” of the cell. Sorts, packages, and exports proteins. Resembles a stack of hollow pancakes.

  34. Eukaryotic Cellular Organelles (TRANSPORT VESICLES) Membranous sacs used to transport materials such as proteins. Produced by Golgi Complex.

  35. Eukaryotic Cellular Organelles (MITOCHONDRIA) Known as the “Power House” of the cell. Use oxygen to breakdown glucose so energy can be harvested for the cell. Bring in glucose and oxygen, release carbon dioxide and water.

  36. Eukaryotic Cellular Organelles (LYSOSOMES & PEROXISOMES) • Membranous sacs containing enzymes. • Lysosomes clean up cellular debris and destroy foreign materials. • Peroxisomes contain catalase and help neutralize harmful chemicals.

  37. Eukaryotic Cellular Organelles (CELL WALL) • Found in plants, algae, and fungi. • Composed primarily of cellulose in algae & plants. • Composed of chitin in fungi. • Provides structural support.

  38. Eukaryotic Cellular Organelles (CHLOROPLAST) • Found in plant cells & algae. • Membrane-bound organelle that contains photosynthetic pigments. • Site of photosynthesis, the production of carbohydrate (sugars).

  39. Eukaryotic Cellular Organelles (CILIA AND FLAGELLA) • Cilia are short, numerous and hair-like. They are used to create currents. • Flagella are long and whip-like and are used for locomotion. • 9 + 2 arrangement of microtubules.

  40. PROKARYOTIC CELL STRUCTURE • All bacterial cells are prokaryotic cells. • Prokaryotic cells are approximately 10 times smaller than eukaryotic cells. • Prokaryotic cells do not contain a membrane-bound nucleus or membrane-bound organelles. • Prokaryotic cells do contain specialized intra-cellular structures.

  41. Prokaryotic Cellular Structures(CELL MEMBRANE & CYTOPLASM) • Cell membrane of prokaryotic cells is similar in structure to that of eukaryotic cells. • Cytoplasm of prokaryotic cells is similar in structure to that of eukaryotic cells. • Prokaryotic cells contain enzymes to carry out photosynthesis, cellular respiration, and other metabolic functions.

  42. Prokaryotic Cellular Structures(CHROMOSOME & PLASMIDS) • The bacterial chromosome is composed of a single, closed loop of naked DNA. • Some bacteria also have small, circular loops of DNA known as Plasmids. • Plasmids are also known as “R” factors because they sometimes code for bacterial resistance to antibiotics.

  43. Prokaryotic Cellular Structures(RIBOSOMES) • Bacterial ribosomes occur singly or in clusters, they are not associated with membranes. • They are the site of protein synthesis (Protein Factories). • Bacterial ribosomes are smaller than eukaryotic ribosomes. • Some antibiotics target bacterial ribosomes.

  44. Prokaryotic Cellular Structures(INCLUSION BODIES) • Inclusion bodies are specialized structures inside the prokaryotic cell. Examples include metachromatic granules and starch granules. • Metachromatic granules are bodies of stored phosphate. • Starch granules are bodies of stored starch (long-term energy).

  45. Prokaryotic Cellular Structures(CELL WALL) • The vast majority of bacteria have a rigid exterior cell wall that protects against dehydration, abrasion, & environmental threats. • The cell wall is composed of peptidoglycan. A compound composed of polysaccharides and protein. • Some bacteria have a thick cell wall and are referred to as Gram +, some have a thin cell wall and are Gram -

  46. Prokaryotic Cellular Structures(GLYCOCALYX) • The glycocalyx is located outside the cell wall of some bacteria. • There are two types of glycocalyx: the slime layer and the bacterial capsule. • The slime layer is loosely attached and aids in locomotion. • The bacterial capsule is firmly attached and enhances the pathogenicity of some species (ex. Streptococcus pneumoniae).

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