Test Questions & Notes (Exam 1 )

Test Questions & Notes (Exam 1 ) Electron Microscopy: • doesn't use visible light • higher resolution • Magnification far greater than 100x • Enables observations of subcellular, organelles & viruses Two types TEM: this miscrope is use when sample is very thin SEM: scan the specimen & reflected by a stain to reveal 3D surface Which term refers to a lens’s ability to produce clear, nonblurry images of a microscopic object? Resolution The ocular lens of a compound light microscope is the lens that is closest to the observer’s eyes. If you are using the low power objective lens to view an object with a compound light microscope, what is total magnification of the specimen? 100X Routes disease can take Skin Parental Oral Respiratory Test Question notes (Exam 1) Define the cell theory All organism are comprised of cells All cells comes from cell - spontaneous The cell is the fundamental unit of life generation The germ theory How do we define a microbe using the cell theory Specific disease are Microorganism can be unicellular, multicellular Eukaryotes vs Prokaryotes Eukaryotes has a nuclues, includes fungi, protozoa, algae caused by microscopic “germs” Prokaryotes has no nucleus, another word for bacteria , includes archae Who was Robert Koch & what did he do Develop the first scientific method for establishing the microbial cause of a disease He identified bacteria responsible for tuberculosis Who was Van Leeukhook & what did he do The father of microbiology, he discovered both protists & bacteria The 3 domain system Bacteria Are prokaryotes Archae Are prokaryotes Don't cause disease Lack pathogenicity The Genus, Type & Species Yersinia pestis Species Genus What did Alexander Fleming do Discovered penicillin Eukaryota Are eukaryotes Who is Louis Pasteur & what did he do Discovered that microorganisms causes fermentation & diseases Developed vaccine against anthrax and rabies Who was Watson & Crick They did discovered double helix structure of DNA Who was Edward Jenner Created the small pox vaccine, the world first vaccine Difference between mutualism, commensalism & Mutualistic: Probiotics Commeulustic: Dont help, just there, no harm or benefit Paratism: one species benefits one harmed What is an endosymbiotic Where one organism lives inside the other What is infectious disease a disease caused by a microorganism (bacterial,viral or parasitic) that can be transferred from one host to another. What is virulence Virulence describes the level of harm caused by a pathogen following infection What is lethal dose Difference between sign, symptom & syndrome Signs: Can be observed by examination Symptoms: Are experienced by the person : Pain , Fatigue Syndrome is a group of symptoms that consistently occur together & collectively characterized a condition Acute disease appears suddenly & last for a short period of time Subacute disease In which symptoms are less pronounced but more prolonged that in Acute Chronic disease develop slowly & may worsen over an extended period of time Simple vs complex infection cycle Simple : direct transmission from current to future host Complex: transmission occurs through multiple intermediate hosts of vectors Vector Insect Vectors microbes can be transmitted from animal to Vectors : ticks, mosquitoes animal ( & to humans ) by insect vectors Fomite Objects or materials, such as clothes, utensils etc Indirect Transmission microbes can be transmitted indirectly by an inanimate objects ( fomites) , by vehicle transmission or by an insect vector Ectoparasites: such as a flea, that lives on the outside of its host Endoparasites : Inside the blood, inside the body What is a reservoir A reservoir is an animal (including humans) or an environment that normally harbors the pathogen. Vertical Transmission transmission of an infectious agent from an insect to its offspring Vehicle Transmission some microbes can be transmitted through contaminated fomites, food , water or air Direct Transmission microbes can be transmitted by direct contact or by aerosolization Primary Pathogens are likely to cause disease after infection in a healthy host • rapidly reproduce/ increase in numbers • Moderate to high virulence Opportunistic Pathogen are less likely to cause disease in a healthy host • Low Virulence Different types of routes diseases can take Respiratory: Portal is the mucosa of the respiratory tract Urogential: Portal is the mucosa of genital & urinary tracts Fecal- Oral : Portal is the mucosa of the GI Tract Parental: Portal is through breaks in skin What is Bsl lab & different levels 1, 2, 3,4 BSL 1 – low risk, basic precautions BSL 2 – human pathogens causing mild disease, barrier precautions BSL 3 – human pathogens causing serious illness; separate rooms, work done in BSC BSL 4 – high virulence pathogens where exposure can be lethal; separate facilities Different virulence factors in a pathogen Promote attachment and colonization of host tissues (invasion) Facilitate pathogen spread from the initial site of infection (invasiveness) Have a toxic effect on cells/tissues/host physiology (toxins) What host factors can contribute to virlence factors Immunity Pathogenicity Different shapes of bacteria Different objective magnifaction 4x, 10x, 40x,100x Binocular definition has two lenses that you look through with both eyes Compound type microscope Viewing samples high magnification which is achieved by the combined effect of two set of lenses What is working distance The distance from the front lens of the element of the objective to the closet surface What is Field of view The maximum area visible when looking through the microscope eyepiece Relationship between frequency & wavelength The wave with the greatest frequency has the shortest wavelength.Inversely proportional to each other Different ways light behaves Reflected Scattered Refracted Transmitted Different types of microscopy Bright-field Dark field TEM SEM Phase contrast Polarized Diffracted Absorbed What is differential stain & what can it tells us When more than one dye is used to differentiate between 2 types of microorganisms on a slide Helps differentiate between cell types & cell structures What is simple stain & what can it tells us When a single stain or dye is used to help visualize Tells cell shape and arrangement