Microbiology Exam 1 Study Guide PDF

**[Ch. 1 & Ch. 3]** 1\. Define microbiology and microorganisms. Know and differentiate the different groups of microorganisms i.e., Bacteria, Archaea, and Eukarya. Compare and contrast prokaryotes and eukaryotes. Distinguish between pathogen and non-pathogenic microorganisms. Know the structures us...

**[Ch. 1 & Ch. 3]** 1\. Define microbiology and microorganisms. Know and differentiate the different groups of microorganisms i.e., Bacteria, Archaea, and Eukarya. Compare and contrast prokaryotes and eukaryotes. Distinguish between pathogen and non-pathogenic microorganisms. Know the structures used for locomotion and attachment in bacteria and eukaryotic cells. What are helminths? Know the different types, their general life cycle, and how they are transmitted. **- Microbiology is the specialized study of organisms ordinarily too small to see without magnification.** **- Eukarya have a nucleus and organelles. They contain animals, humans, fungi, and protozoa. The most prominent/visible organelle is the nucleus.** **- Archaea and Bacteria lack a nucleus and organelles. Archaea have histones while bacteria do not. Bacteria have a sturdy cell wall made of peptidoglycan. Archaea have cells walls made from other chemicals. A few bacteria and archaea have microcompartments.** **- See venn diagram on Chapter 1 notes.** **- Pathogenic microorganisms cause disease to the host while non-pathogenic microorganisms do not cause disease.** **[- Locomotion Structures Bacteria (3 distinct parts):]** - **[The filament:] helical structure made of proteins. Moves counterclockwise toward stimuli and clockwise away from stimuli.** - **[The hook (sheath):] anchored to the cell by the basal body and is what the filament is attached to** - **[The basal body:] stack of rings anchored through the cell wall to the cytoplasmic membrane and the outer membrane** **[- Helminths - chapter 4]** 2\. Define phylogeny and evolution. Understand endosymbiosis and how it provides an evolutionary relationship between prokaryotic cells and eukaryotic cells. **- Evolution is the accumulation of changes that occur in a species as they adapt to their environment.** **- Phylogeny is the study of evolutionary history of a group of organisms.** **- Endosymbiosis -- chapter 4** 3\. Describe the composition of bacterial cell envelope. Know the function of each component. Distinguish between gram-positive and gram-negative bacteria as well as acid fast bacteria. Know the gram stain procedure. **[- The CELL ENVELOPE] is made of the cell wall, cytoplasmic membrane and outer membrane (gram-negative bacteria).** **[- The CELL WALL:] helps determine the shape of bacteria and provides strong structural support to keep it from bursting from osmotic pressure** **[- The CYTOPLASMIC MEMBRANE:] Just beneath the cell wall and is in direct contact with the cytoplasm** **[- The OUTER MEMBRANE:] Only present in gram-NEGATIVE bacteria -- made of a lipid bilayer that's outside of the cell wall. Allows relatively small molecules to pass through and helps in communication.** **[- ACID-FAST BACTERIA:] Have cell walls with an unusual composition of waxy lipid components (mycolic acid). Requires acid-fast staining which stains bacteria red (carbolfuchsin) while other bacteria retain a blue color.** **[- GRAM-POSITIVE BACTERIA:] Have a thick peptidoglycan wall but no outer membrane. They stain red while gram-positive bacteria stain purple.** **[- GRAM-NEGATIVE BACTERIA:] Have an outer wall and a thin peptidoglycan cell wall. They stain purple when gram-stained.** **[- GRAM-STAIN PROCEDURE:] Bacteria are stained with crystal violent. The dye is then fixed with iodine mordant. The cells are decolorized with alcohol. Gram-positive bacteria remain purple while gram-negative bacteria become colorless. Safranin is then added to stain gram-negative bacteria red.** 4\. Describe the virulence/pathogenicity factors of bacteria and how each factor contributes to bacteria's ability to cause disease. **Pili or fimbriae bind to epithelial cells (such as E.coli binding to urinary tract to cause UTI).** **Toxic proteins called exotoxins are secreted and cause damage to host tissues.** **The lipopolysaccharides (LPS) on the outer membrane of gram-negative bacteria have toxic components called endotoxins which triggers immune responses leading to fever, inflammation, and sepsis.** **A polysaccharide capsule surrounding the cell wall can protect bacteria from phagocytosis by immune cells.** 5\. Describe the function of bacterial endospores and the process of formation. Name three groups of bacteria that form spores. Distinguish between bacterial spores and fungal spores. Understand and explain bacterial conjugation. **[- Function of Bacterial Endospores:] Survival mechanism that allows bacteria to withstand extreme conditions that would normally kill a vegetative cell. [ ]** **[- Process of endospore formation:] Sporulation occurs when bacteria are exposed to a scarcity in nutrients. Chromosome is duplicated and separated into a sporangium (mother cell) and a forespore. Sporangium engulfs the forespore and creates layers around the forespore (now an early endospore). [ ] Calcium is deposited and a cortex is formed to create a mature endospore. Free endospore is released with the loss of the sporangium.** **[-Three groups of bacteria that form spores:] Bacillus, Clostridium, and Sporosarcina.** 6\. Describe bacterial shapes and arrangement. How do spirochetes move? **Shapes:** **- Coccus, rod-shaped, spirochetes** **Arrangements:** **- Coccus: Single cocci, diplococci (pair), tetrads (group of four), irregular cocci (staphylococci and micrococci), chains of cells (streptococci)** **- Cubical grouping: sarcina** **- Rods: Pair of cells with their ends attached (diplobacilli), chain of several cells (streptobacilli), cells of a chain remain partially attached at a hinge (palisades)** 7\. How are microbes useful to humans? Read the section titled 'Microbes and Humans' in chapter 1 (slide 8-12). Understand how they can impact the environment, the food production industry, medicine etc. **Bread, alcohol, and cheese production. Treatment of wounds and lesions, mining precious metals, and cleaning up human-created contamination.** 8\. History of Microbiology: Antonie van Leeuwenhoek, Louis Pasteur, Robert Koch, Christian Gram, Joseph Lister. Know these microbiologists/scientists and their contributions to the development of the field. **-Antonie Van Leeuwenhoek: "Father of microbiology" - refined the microscope and described bacteria & protozoa as "animacules"** **-Louis Pasteur: Pasteur's Experiment involved swan necked flasks filled with broth. The flask open to air but bent at the neck trapped microbes in the neck so the broth was still sterile. Disproved spontaneous generation.** **-Robert Koch: Established *Koch's postulates*, a series of logical steps that verified the germ theory and established whether an organism was pathogenic and which disease it caused.** **-Christian Gram: Developed the Gram stain which distinguishes between different groups of bacteria based on their cell envelope structure** **-Joseph Lister: Introduced aseptic techniques designed to reduce microbes in a medical setting. Mainly involved disinfecting the hands and air with strong antiseptic chemicals prior to surgery.** 9\. Biological polymers/macromolecules and their monomers: carbohydrates (monosaccharides, disaccharides, & polysaccharides), proteins, lipids, nucleic acids. What chemical reactions are used to join monomers and break them? What role does each polymer play in the cell? **Carbohydrates: monosaccharide. Structural support, protection, nutrient, and energy stores.** **Lipids: glycerol (3-carbon alcohol with 3 OH groups). Storage lipid for energy used in metabolism. Main constituent of all cell membranes.** **Proteins: Amino acids. Used to build enzymes for catalyst in all chemical reactions in cells.** **Nucleic Acids: nucleotides. Build special coded genetic program with detailed and specific instructions for each organism's heredity** 10\. What is the role of ATP in the cell? How is it generated? **ATP is a nucleotide containing adenine, ribose, and 3 phosphates. It gives off energy when the bond is broken between the second and third phosphate making ADP. These bonds make it possible for ATP to release and store energy. ADP can store energy when the third phosphate is restored, making ATP.** **[Ch. 4]** 11\. Describe how fungi cause disease in humans and distinguish between yeast and mold. 12\. Know and explain the beneficial impacts of fungi. 13\. Eukaryotic organelles and their functions. How is the eukaryotic cell membrane different from bacterial cell membranes? 14\. Protozoans: Trophozoite vs. cyst, amoeba diseases and mode of transmission. 15\. What are helminths? Know the different types, their general life cycle, how they are transmitted and cause disease.