Microbiology Study Guide - Exam 1 & 7 PDF

[Chapter 1 ] Microbiology- study of living things too tiny to be seen by the unaided eye Microorganisms- the small forms of life we can not see with an unaided eye [What are the groups of microorganisms? ] - - - - - - - [Microbes and Diseases: ] How do these microbes and disease...

[Chapter 1 ] Microbiology- study of living things too tiny to be seen by the unaided eye Microorganisms- the small forms of life we can not see with an unaided eye [What are the groups of microorganisms? ] - - - - - - - [Microbes and Diseases: ] How do these microbes and diseases spread? - Spread to humans by respiratory droplets, dust, water, food, injury, insect bites, animals, human contact and inanimate objects Pathogen- microbes that cause disease [Pioneers of MicroBio] 1665- Robert Hooke: used the term cells 1674- Leeuwenhoek: sees microorganisms for the first time 1796- Jenner: vaccine for smallpox through inoculation 1847- Semmelweis: found the cause of childbed fever 1854- John Snow: Epidemiology 1895- Pasteur: disproves spontaneous generation 1865- Lister: introduced antiseptic techniques 1876- Koch: pure culture on agar 1892- Iwanowski: discovers viruses 1894- Ehrlich: selective toxicity 1929- Flemming: discovers penicillin 1977- Woese: classifies archae Robert Hooke: - - - Antoni Van Leeuwenhoek: - - - Spontaneuos Generation- life is formed from inanimate objects [Summary:] Spontaneous generation was the old belief that living things could come from non-living things. For example, people once thought that maggots just appeared in rotting meat or that mice could form from dirty clothes and wheat. Louis Pasteur: demonstrated that animalcules (microbes) arise from other animalcules in the air. Louis used the swan-neck flask Figure 1.1 to prove organisms did not spontaneously generate from nothing. Performed a series of experiments with boiled nutrient broths in swan-necked flasks \* Flasks with intact necks stayed sterile \* Flasks with broken necks were exposed to the air; microbes grew in these broths - - - Pasteurization- is a process that uses heat to kill harmful bacteria in food and drinks, like milk and juice, without ruining their taste. - [Germ Theory of Disease: ] Koch's Postulates 1. 2. 3. 4. [Gelatin and Agar: ] **Koch** also discovered pure cultures of bacteria grew best on a solid culture surface. - - Which two scientists contributed to the new field of bacteriology? - [Pasteur and Kochs contributions to bacteriology:] - - - - [Edwards Jenner and Immunity]: - - - - [Female Contributions to Microbiology: ] Dr. Ruth Ella Moore- found treatment for TB Dr. Jane Hinton- co-developed Mueller-Hinton Agar June Almeida- first saw Coronavirus in electron microscope [Paul Erhlich and selective toxicity ] - - Modern Bacteriology Terms and Definitions: Bacteriology -- study of bacteria Virology - study of viruses Mycology -- study of fungus Parasitology -- protozoa and helminthes Immunology -- study of the immune response [4 areas of microbiology] --Medical Microbiology [Which is more abundant on earth viruses or bacteria? ] - [Microbes and the Human Body: ] - - - - - - - [Drug Resistant Pathogens:] What is the reason for declining effectiveness of many antibiotics? - - - Bioterrorism:Intentional or threatened use of biological agents to cause fear or inflict death/disease [Top 4] - - - - Dehydration synthesis: when two molecules stick together to form a bigger molecule, and in the process, they lose a water molecule. Hydrolosis: when a big molecule breaks into smaller pieces, and to do this, it uses a water molecule. Cohesion: Water molecules stick together by forming large numbers of hydrogen bonds [Acids/Bases and pH: ] Acids: chemicals that increase H^+^ ions when they dissolve in water Bases: chemicals that donate OH^--^ ions that tie up H^+^ ions in solution by forming water molecules pH- a measurement of H^+^ ions in a solution. Acidic: less than 7 (0-6) Neutral: 7 Basic/Alkaline: More than 7 (8-14) Buffers: are like tiny sponges that help keep the pH of a solution steady. If something makes the solution too acidic or too basic, the buffer soaks it up to keep it balanced. [Proteins and there makeup: ] Proteins are made up of- Carbon, hydrogen, oxygen, nitrogen, and sulfur polymers; built from chains of amino acids Amino Acid: Building blocks of protein and determines their function and forms bonds Made up of: Carbon, hydrogen, oxygen, nitrogen, and sulfur polymers; built from chains of amino acids [Protein Shape and Function:] Primary structure = polypeptide chain of amino acids Secondary structure = pleated sheets, alpha helices, coils Tertiary structure = bonding between R groups to create final 3-D shape of polypeptide Quaternary structure = two or more folded polypeptides bonded together Denaturation: proteins with broken bonds unfold and begin to lose function \> leads to cell death Nucleic Acids: Unbranched organic molecules of carbon, hydrogen, nitrogen, and phosphorous atoms 2 forms: DNA and RNA Makeup: - - - - Rungs: are nitrogenous bases held together with hydrogen bonds. [DNA:] Double Helix carries units of information called genes arranged on chromosomes (circular or linear) A\>T C\>G [RNA:] single stranded Intermediaries in carrying message to construct cellular proteins (mRNA) Genetic information unit in some viruses Regulate gene activity Regulate protein synthesis - U binds with T instead of A [Central Dogma of Life] **Reflection** --Light hits an opaque object **Transmission** --Rays pass through the object --Must be clear transparent **Absorption** --Some light does not pass through **Refraction** [Types of microscopes: ] [Microscope and its parts: ] Compound microscope Total magnification Objective lens X ocular lens Low power = 10x High power = 40x Oil immersion = 100x Ocular lens = 10x On low power the total magnification = 100x On high power the total magnification = 400x With oil immersion total magnification=1000x [Other light microscopes: ] Phase contrast microscopy Darkfield microscopy Fluorescence microscopy \- Fluorescent material illuminated by UV light [Electron Microscopes: ] - - - - [Comparison of microscopes on a table chart: ]  [Wet Mount Procedure: ] Simple sample preparation for microscopic viewing Observe living microorganisms Usually not stained May use a vital stain A step by step procedure of wet mounting! [What are stains used for?] - [Simple Stain procedure:] [Special stains: ] Heat fixation: it's like temporarily \"freezing\" the cells in place with heat to make sure they stay intact and visible under the microscope [Types of dyes] [Explain the difference between simple stain and differential stains: ] Simple stains Differential stains When: 1884 Who: Developed by Danish bacteriologist Christian Gram Purpose: Divides bacteria into two groups Gram-positive --purple/blue Gram-negative [The Gram Stain Procedure: ] 1. 2. 3. 4. 5. This helps differentiate between G+ (purple) and G- (pink) bacteria. [Gram Positive stain and Gram Negative stain Difference: ] \- Bacterial cell walls are made of peptidoglycan Gram [negative] cell wall the peptidoglycan mesh is only one layer thick Gram [positive] cell wall the peptidoglycan mesh is many layers thick [Importance of Gram Stains: ] Can diagnose some types of infection Bacterial Meningitis Gonorrhea in men [Capsule Stain: ] Why: used to highlight the capsule surrounding certain bacteria (simple negative stain) How: **Negative Stain**: A dark stain (like India ink or nigrosin) is used to stain the background, leaving the capsule clear. **Counterstaining**: The bacteria are stained with a different color, making them stand out against the dark background. [Endospore stain: ] Why: used to detect bacterial endospores, which are tough, dormant structures that some bacteria form to survive harsh conditions. How: **Primary stain (Malachite green)**: The slide is heated with malachite green to stain the endospores. The heat helps the stain penetrate the tough spore coat. **Decolorize (Water)**: After staining, the slide is washed with water, which removes the green stain from the bacterial cells but not from the endospores. **Counterstain (Safranin)**: A red stain (safranin) is applied to color the rest of the bacteria (not the endospores). The result: - - [Acid Fast Stain: ] Why: used to identify bacteria with thick, waxy cell walls, like *Mycobacterium* (which causes tuberculosis) How: **Primary stain (Carbol fuchsin)**: The slide is heated with carbol fuchsin, which stains the bacteria red. The heat helps the dye penetrate the waxy cell wall. **Decolorize (Acid-alcohol)**: The slide is washed with acid-alcohol, which removes the red stain from most bacteria, but not from acid-fast bacteria (because their waxy cell walls hold onto the stain). **Counterstain (Methylene blue)**: A blue stain (methylene blue) is applied, coloring the non-acid-fast bacteria blue. The result: Acid-fast bacteria (like *Mycobacterium*) stay red. Non-acid-fast bacteria turn blue. [Chapter 3 Part 2 (Eukaryotic and prokaryotic) ] Homeostasis: organisms strive to maintain a stable internal state EX: Temperature, sunlight, pH, toxic substances, salt concentration  [Bacteria and Biofilms:] - [Prokaryotic Cells: ] - - [Eukaryotic cells: ] - All organisms except bacteria (and Archaea) All other microorganisms that are cells fungi, algae, protozoa - [Similiarities: ] \- Both use flagella for movement \- Many have cell walls for helping maintain water balance \- Both can perform photosynthesis [Shapes of Prokaryotes: ] Morphology- Determined by cell wall - - - [Which of the following is larger in size bacteria or eukaryotic cells? ] - [Eukaryotes VS Prokaryotes: ] Prokaryotic: No nucleus No membrane-bound organelles Cell wall contains peptidoglycan Size: less than several micrometers Eukaryotic: Nucleus Membrane-bound organelles No peptidoglycan even if cell wall present Size: may be 10 times larger Taxonomy: is the science of classification, involving arranging related organisms into logical categories EX: *Bacillus subtillus* Bacillus: GENUS subtillus: Species  \* Notice the form of Reproduction for each. [Chapter 4 Prokaryotic Cells ] Structure of Prokaryotic Cell: [Appendages: ] Located on outside Pilli- straight hair like appendages Flagella- long thin structures - locomotion - motile bacteria [Prokaryotes movement: ] Chemotaxis- away or towards a chemical Phototaxis- sense light sensitivity Aerotaxis- moving where oxygen concentration is more favorable Magnetotaxis- movement along magnetic lines in the soil [Prokaryotes- outermost layer: ] Capsule (glycocalyx) - - [Prokaryotic cell Envelope: ] - 3 layered structure: \* Gram negative - have lipopolysaccharide (LPS) outer membrane \* Gram positive - do not have the outer membrane \* Mycoplasma - have only the cell membrane [Prokaryotic Cell Wall: ] - - Which bacteria is a cell wall NOT found in? - Cell membrane- Membrane that encloses the cytoplasm of any cell Function - containment & transport \* Regulates passage into and out of cell Membrane proteins: 2 types- Integral proteins ( stuck inside ) - - Peripheral proteins ( stick to the surface ) - - [Functions of membrane proteins: ] - - - - - Cytoplasma: 1. 2. 3. Key parts inside: - - **Inclusion Bodies** → Tiny storage spots inside the cell that keep extra nutrients or materials. Think of them as **tiny storage bins** for the cell. **Storage Granules** → Hold things like sugars, fats, or phosphate for later use. Like **snack reserves** for the cell. **Gas Vacuoles** → Help bacteria float by filling with gas. Like **tiny balloons** inside the cell, helping them stay at the right depth in water. **Chlorosomes** → Found in some bacteria that do photosynthesis, they **capture light energy** like **solar panels** for the cell. **Magnetosomes** → Contain tiny magnetic crystals that help bacteria **sense direction** like a **compass**, guiding them to the right environment. [Prokaryotic Endospore: ] Hardy, resting, non-growing structure Produced by some bacteria Endospores may survive in the environment for years (100's ?) With stand, heat, dehydration, toxic chemicals, and radiation Sporulation- unequal cell division begins Sporulation is when bacteria or fungi make spores to survive tough conditions. The spores can \"wake up\" and grow when things improve. [Chapter 7 Prokaryotic Reproduction] Growth = increase in number of bacteria cells - Asexual Reproduction - Binary Fission - - - **Cell growth phase** - - **DNA replication phase** - **Binary fission phase** - - Generation time- Time between binary fissions is the doubling time or generation time - - **Logarithmic Phase** - **Stationary Phase** - **Decline Phase** - [Pure culture: ] - - Two Steps to obtaining a pure culture: [Streak Method of pure culture- ] 1. 2. 3. 4. 5. [Chapter 5 Eukaryotic Microbes] [Eukaryotes appendages:] Flagella- Purpose is to have motility Cillia- to move things across the surface of the cell or help the cell move [Nucleus:] Function- contain the DNA Nuclear membrane - - Nucleoplasm Nucleoli [Eukaryotes: edomembrane system: ] Function- sorting and transport of synthesized molecules Includes: Endoplasic Reticulum, Golgi apparatus, Lyosomes Rough Er- ribosomes attached Smooth er- no ribosomes Golgi apparatus- stacks of flattened membrane sacs molecules are modified Vessicles- transport Three types of fibrous proteins: Energy production Double membrane system Mitochondria Chloroplasts (plants) - - - - Mycosis- fungal infection Yeast- single cell that reproduce by Budding Molds- interconnected system of branched, tube-like filaments Hyphae- individual filaments Mycelium- connected hyphae [Asexual reproduction- ] [Sexual Reproduction- ] spores [Mycoses]- Most often acquired from nature, Treatment is difficult Toxins- [Why are most antifungal agents toxic to human cells? ] - Dimorphic- have yeast and mold forms [Yeast are unicellular fungi ] [Mold is filamentous fungi ] [Protozoa: ] Unicellular eukaryotic organisms The most complex one cell organisms Organelles Four groups- based on motility - - - - [Helmniths:] worms that cause parasitic diseases and are multicellular organisms - - [Chapter 6 Viruses and Prions: ] Viruses- A microscopic packet of nucleic acid usually wrapped in protein - - [History of viruses:] Before germ theory of disease; all mysterious agents that poison the body were called viruses 1800's knew that bacteria caused disease and could be removed from a solution by filtering 1892 - reported that sterilization by filtration did not remove the cause of mosaic disease in tobacco plants Called filterable viruses [Viruses VS Bacteria: ] Both are infectious agents Viruses are not visible with light microscopes Viruses are 1/10 to 1/3 the size of bacteria Some bacteria live inside host cell Bacteria are alive Bacteria may be grown in the laboratory on culture media Viruses may be grown in cell culture [Virus Structure: ] Virion is the intact virus particle Capsid is the protein coat Some viruses have a membrane around the capsid called the envelope Proteins may be in the envelope - glycoprotein spikes All viruses have a nucleic acid core for storage of genetic material that is either DNA or RNA  [What is the only virus that has a cure so far? ] Hepatitis C [Why do antibiotics not work on viruses? ] Viruses are also protected once they are inside host cells [What is used to help prevent viral infections? ] - [Important terms Tumors: ] Viroids- Circular molecule of ssRNA