Microbiology FINAL EXAM Review Flashcards Questions & Answers Rated 100% Correct!!

Microbiology FINAL EXAM Review Flashcards Questions & Answers Rated 100% Correct!! 1. What are microorganisms? microscopic organisms, or microbes includes bacteria, protozoa, fungi, algae and helminths 1. How are the names of microorganisms written? Capital Genus, lower case species name (binomial system of nomenclature) *italicized if typed or underlined if written 1. In what ways do humans use microorganisms? *genetic engineering, GMOs, recombinant DNA technology, food industry, products in industrial settings, bioremediation, fuel sources 1. What is bioremediation? introduction of microbes into the environment to restore stability or to clean up toxic pollutants, break down chemicals that would be harmful to other organisms 1. What is the role of microbes in decomposition? Bacteria and fungi breakdown dead matter and wastes into simple compounds that can be recycled back into natural cycles of living things. (Main forces that drive the structure and content of the soil, water and atmosphere of earth.) 1. What is a pathogen? any agent (usually a virus, bacteria, fungus, protozoan or helminth) that causes disease 1. Compare and contrast prokaryotes with eukaryotes. Prokaryotes- no nucleus, bacteria, simple, ancient Eukaryotes- have a nucleus, fungi, protozoan, algae, plant, complex 1. What was the contribution of Lister? British surgeon and a pioneer of antiseptic surgery, promoted the idea of sterile portable ports while working at the Glasgow Royal Infirmary. Lister successfully introduced carbolic acid (now known as phenol) to sterilize surgical instruments and to clean wounds, which led to a reduction in post-operative infections and made surgery safer for patients, distinguishing himself as the "father of modern surgery" 1. What was the contribution of Semmelweis? Ignaz Semmelweis was a Hungarian physician whose work demonstrated that hand-washing could drastically reduce the number of women dying after childbirth 1. What was the contribution of Pasteur? *Pasteur was responsible for disproving the doctrine of spontaneous generation. *created the first vaccines for rabies and anthrax. *renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization 1. What was the contribution of Leeuwenhoek? Constructed lenses to make microscope and examined scrapings from teeth, rainwater from a pot, and threads in fabrics. "Father of Bacteriology and Protozoology" 1. What was the contribution of Koch? What are Koch's Postulates? * first to link a microscopic organism with a specific disease Koch's Postulates (1) find evidence of a microbe in every case of disease. (2) isolate that microbe, cultivate--> pure, study (3) Inoculate a healthy subject with isolate, observe disease (4) Reisolate the same agent from subject CHAPTER 3- CULTURING AND MICROSCOPY ********************************************** 3. What is a pure culture? substance that is composed of a single species 3. What is a selective media? a selective media contains one or more agents that inhibit the growth of a microbe or microbes (A, B, C) but not others (D) and thereby "select" microbe D and allow it to grow Ex: Mannitol Salt Agar 3. Compare the uses of transmission and scanning microscopes. Transmission Electron Microscope- produces image by transmitting electrons through the specimen, extremely thin slices, stained or coated with metals, view detailed structure of cells Scanning electron Microscope- extremely detailed 3D view, bombards surface of a whole metal coated specimen with electrons while scanning back and forth over it, image is black and white 3. Describe the Gram stain and how it is used in bacterial identification. Universal diagnostic staining technique, differential stain gram positive= stain purple gram negative= stain pink Basis for bacterial taxonomy, cell wall structure, ID and diagnosis of infection 3. Tell the microbe that has a positive Acid-fast stain Differential stain acid fast bacteria = pink non-acid fast bacteria= blue * detects Mycobacterium tuberculosis, mycolic acid in waxy outer coating hold the dye (carbol fuchsin) even when washed with acid alcohol CHAPTER 4 PROKARYOTIC MICROBES (BACTERIA) ********************************************** 4. What is the function of the bacterial cell wall? Cell wall- semirigid casing that provides structural support and shape for the cell, keeps bacteirum from bursting or collapsng because of osmotic pressure changes * Gram + thick layer of peptidoglycan * Gram - Lipopolysaccharide layer, thin peptidoglycan 4. What is the function of the bacterial capsule? Capsule= a coating of molecules external to the cell wall, protection, adhesion and receptor functions, glycocalyx *slime layer when it is loose * capsule when it is bound tightly to the cell * protect against white blood cells phagocytes, capsular coating blocks the mechanisms that phagocytes use to attach to and engulf bacteria 4. What is the function of the bacterial cell membrane? cell membrane= thin sheet of lipid and protein regulates what enters and leaves the cell 4. What is the function of the bacterial nucleoid? nucleoid= nuclear region or body that contains the bacterial chromosome 4. What is the function of the bacterial inclusion? inclusion (granule)= stored nutrients such as fat, phosphate, or glycogen deposited in dense crystals or particles that can be tapped into when needed 4. What is the function of the bacterial endospores? Endospores= dormant body formed within some bacteria (Bacillus and Chlostridium) that allows for their survival in adverse conditions 4. What is the function of the bacterial ribosomes? ribosomes= protein synthesis 4. What is the function of the bacterial plasmids? Plasmids= double stranded DNA circle containing extra genes 4. What is endotoxin? endotoxin= phospholipid-polysaccharide complex that is an integral part of gram-negative bacterial cell walls, can cause severe shock and fever CHAPTER 5- EUKARYOTIC MICROBES *********************************************** 5. Describe yeast- cell wall, photosynthesis? forms? nutrients? Yeast belong to fungi kingdom * cell wall- polysaccharides, lipids and chitin *anaerobic respiration-sugars are converted into ethanol. This is called fermentation. * forms- single nucleated cell * reproduction- asexual buds or pseudohypha form 5. Describe algae cell wall material, photosynthesis, contribution algae makes to environment. *algae cell wall- made of glycoproteins and polysaccharides. * photosynthetic, make up floating community of plankton *essential role in aquatic food web * produce most of the earth's oxygen What is the function of the protozoan cyst? protozoan cyst= dormant resting stage when environmental conditions become unfavorable, thick cuticle around the cell membrane makes it resistant to heat, drying and chemicals 5. What is a helminth? Give examples. Helminths- collective term for tapeworms, flukes, and roundworms Ex: pinworm (roundworm) cestode (tapeworm) tremetode (liver fluke) 5. Describe the pathogenic protist- Plasmodium. Malaria parasites are micro-organisms that belong to the genus Plasmodium. (insect as vector, human host for four different species of Plasmodium) treatment- quinine, chloroquine CHAPTER 6- VIRUSES ********************************************** 6. What are three unique characteristics of viruses? They are infectious ____________ (rather than organisms) They can be active or inactive. (Explain difference) They are obligate intracellular parasites. (Explain.) Infectious particles. Active= replicating inside the host cell Inactive= not replicating inside the host cell Obligate intracellular parasites= require a host cell to replicate, harm the host cell in the process, 6. Viruses have only two main parts. What are they? CENTRAL CORE- nucleic acid (either DNA or RNA but not both) COVERING- protein covering (capsid) 6. What are some of the optional structures that a virus may have? COVERING- *envelope (phospholipid bilayer) taken from host cell, (great for fooling the host into thinking it is not an invader *spikes= protruding glycoproteins for attachment to host cell, can be found on capsid or enveloped virus CENTRAL CORE- enzymes matrix proteins 6. Distinguish between enveloped and naked viruses. Enveloped viruses have the host cells phospholipid bilayer surrounding their core. (replaces host proteins with viral proteins) Naked viruses are simply nucleic acid core + capsid * no envelope 6. Explain the different types of nucleic acid possible in viruses- *Positive sense RNA *Negative sense RNA *DNA- ds or ss? * RNA- ds or ss? Positive sense RNA- ready to be translated into proteins Negative sense RNA- need to be converted into proper form before translation can occur DNA- can be double or single stranded RNA- can be double or single stranded 6. Describe the function of the following enzymes- *polymerase *replicase *reverse transcriptase polymerase= makes more DNA or RNA replicase= copy RNA reverse transcriptase- makes DNA from RNA (opposite of what is normally done) 6. What are the five general phases in the life cycle of animal viruses? 1. Adsorption 2. Penetration (uncoating) 3. Synthesis 4. Assembly 5. Release APSAR 6. What is a prion? prion= infectious protein fibril - infects brain tissue - spongiform enchephalopathies (brain looks like a sponge) - long period of latency - mental derangement, loss of muscle control, progressive and fatal Examples: Cruetzfeldt-Jakob disease (CJD) affects Central Nervous system in humans Mad Cow disease- first incidence of prion disease transmission from bovine to humans Scrapie in sheep, mink, elk CHAPTER 7- BACTERIAL GROWTH ********************************************* 7. What is a psychrophile's optimum temperature and range?