MCB 2004 Exam 1 Study Guide Anything text in red she added mentioned Koch s postulates o Agent X must always be present in host s with disease Y and absent in those that do not have disease Y o Must be able to isolate pure culture of agent X o o Agent X can now be re isolated from this new diseased host Introduction of agent X into a new host induces disease Y Be able to convert distances between nanometers nm micrometers um and millimeters mm you can use a calculator for this but it must not be an app in your phone It must be a calculator that does not have networking capability You may not need a calculator the conversions will all be just moving the decimal point based on the conversion factor o 1 mm millimeter 10 3 o 1 m micron 10 6 o 1nm nanometer 10 9 o 1 Angstrom 10 10 o 1 pm picometer 10 12 o Must know how to go both ways ex from nm to mm and mm to nm Know what Pasteur disproved He disproved spontaneous generation for microbes o o Used s shaped flasks to disprove s g Know the details of the discovery of penicillin o In 1928 Alexander Fleming discovered the first naturally occurring antibiotic o He discovered that Penicillum fungus made an antibiotic penicillin that killed Staphylococcus aureus o 1940s Penicillin was tested clinically and mass produced o Interferes with bacterial cell wall biosynthesis inhibits formation of peptide bridges in peptidoglycan Know the causes of the emerging infectious diseases we covered in Lecture 2 slides 33 44 and know the background we discussed on these infectious agents o Pertussis whooping cough diphtheria flu smallpox measles No vaccines smallpox vaccine introduced in 1800 o Spanish Flu 1918 is caused by influenza virus killed 40 50 million people worldwide o Avian Flu Influenza A virus Primarily in waterfowl and poultry Sustained human to human transmission has not occurred o Severe acute respiratory syndrome SARS SARS associated Coronavirus Occurred in 2002 2003 Person to person transmission MERS is also a Coronavirus o Ebola hemorrhagic fever Ebola virus Causes fever hemorrhaging blood clotting First identified near Ebola River Congo Outbreaks every few years Major urban outbreaks last 2 years Liberia Guinea Sierra Leone o West Nile virus causes encephalitis First diagnosed in the West Nile region of Uganda in 1937 Appeared in New York City in 1999 In non migratory birds in 47 states Sexually transmitted o Human immunodeficiency virus HIV causes AIDS First identified in 1981 Worldwide epidemic in 2011 34 million people living Almost 35 million have died form AIDS since the virus Sexually transmitted disease affecting males and with AIDS was identified females Also transmitted by infected blood products and medical equipment HAART highly active anti retroviral therapy saves lives of AIDS patients in developed countries Nobel prizes of 2008 o Bovine spongiform encephalopathy mad cow disease Prion misfolded protein that can cause other proteins to misfold by contact a prion is a zombie protein it is not alive you cannot kill it YOU CAN DISSOLVE IT Also causes Creutzfeldt Jakob disease CJD New variant CJD in humans is related to cattle fed sheep offal for protein o Escherichia coli 0157 H7 A strain of EHEC Enterohemorrhagic E Coli Toxin producing strain of E Coli First seen in 1982 Can be spread in contaminated meat Animals can serve as reservoir cows are asymptomatic carriers Benign not going to hurt you Invasive Group A Streptococcus IGAS o Streptococcus pyogenes Causes Necrotizing fasciitis Can damage huge amounts of tissue o Clostridium difficile bacterium Often acquired in a health care setting this is called a nosocomial infection When a patient s normal intestinal bacteria flora is killed by antibiotic treatment C difficile can take over C difficile infection is often fatal Patients should be isolated Can spread through o Methicillin resistant Staphylococcus aureus MRSA Acquired resistance to multiple antibiotics Overuse of antibiotics selects for antibiotic resistant hospitals strains 1950s Penicillin resistance developed 1980s Methicillin resistance 1990s MRSA also resistance to vancomycin reported VISA vancomycin intermediate resistant S aureus VRSA vancomycin resistant S aureus o Cryptosporidiosis Caused by the Cryptosporidium protozoan Most commonly transmitted via contaminated water and food First reported in 1976 Common cause of diarrheal illness in developing countries and incidence in US is increasing Know the composition of an E coli cell by weight for the major classes of macromolecules we discussed o Water comprises of 70 of the cell o Protein is second most abundant material at 15 Know the approximate size range of bacteria viruses etc and which types of microscopy are useful for each o Small molecule 1nm electron microscope o Cell membrane 10 nm electron microscope o Virus 20 300 nm electron microscope o Bacterium 1 m electron microscope or light microscope o Animal cell and yeast 10 m electron microscope or light microscope o Plant cell 100 m electron microscope or light microscope Be able to define magnification resolution diffraction o o Magnification To increase the apparent size of as a lens does Resolution is the ability to distinguish two points a given distance apart Shorter wavelengths of light provide greater resolution Increasing the resolution means that more fine detail can be observed o Diffraction the process by which a beam of light or other system of waves is spread out as a result of passing through a narrow aperture or across an edge typically accompanied by interference between the wave forms produced Know the major types of microscopy we discussed What type of beam is used etc o Brightfield objective lens o Darkfield Dark objects are visible against a bright background Light reflected off the specimen does not enter the Light objects are visible against a dark background You are looking at light scattered off the specimen as it enters the objective lens Used to observe living unstained preparations o Phase Contrast Microscopy Accentuates diffraction of the light that passes through the specimen Excellent way to observe living cells Especially useful for detecting bacterial components such as endospores and inclusion bodies o Differential Interference Contrast Microscopy Accentuates diffraction of the light that passes through a specimen uses two beams of light o Fluorescence microscopy Uses UV to fluorescent spectrum of light range of wavelengths Fluorescent substances are excited by one
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