Bio 250 lab quiz 1 2023 with complete solution

Bio safety levels (BSL) measure what? an organisms controllability, infectivity, virulence, pathogenicity, antibiotic resistance, vaccine, treatment, mortality. BSL 1 does not normally cause disease in people BSL 2 Associated with disease BSL 3 indigenous/exotic agents that may have serious or lethal consequences and with potential for aerosol transmission BSL 4 dangerous/exotic agents of a life-threatening nature or unknown risk of transmission Containment safe methods and procedures to handle micro organisms Aseptic technique prevents contamination of You Others Experiment Work Area External Enviroment Ubiquitous found everywhere Pathogen micro organisms that cause disease Opportunistic pathogen cause disease in right circumstances Inoculation implantation of micro organisms on or in media Culture cultivation of the micro organisms What has actually grown Turbid cloudy inoculation of growth Colony A discrete mass of millions or more cells ideally from one cell Points of first few labs practice aseptic technique Sterile completely free of all life Pure culture one type of colony Mixed culture more than one type of colony Parfocal once its in focus it stays in focus as you move un in magnification Parcentric What is in the center will stay in the center Why is oil needed for high magnification oil is needed to refract light the same as glass does 4x scanning 10x low power 40x high power (high dry) 100x oil imersion Total magnification ocular magnification X objective magnification Working distance space between slide and lens As magnification increases field of view.... decreases Resolution clarity of an image produced by a set of lenses Resolving power ability of a lens to separate tow objects in a microscopic field Function of wavelength of light and a property of the lens called numerical aperture Numerical aperture mathematical expression that describes the ability of the condenser lens to concentrate light rays from the light source Some refracted light is always lost What are the four factors for maximum resolution and adequate contrast Blue filter Condenser position Diaphram position Immersion Oil What does a three lens system consist of? Occulars Objectives Condenser Blue filter function shorter wavelength Condenser highest position limit light lost Diaphram not completely closed improves contrast but reduces NA immersion oil forms continuous lens system Characteristics of bacterial colonies smaller shiner more numerous Molds larger (diffuse) fuzzy Chromogenesis Production of a color pigment usually via enzyme activity Opacity amount of light that can go throughq Opaque no opacity Translucent some opacity Transpatrent opacity What are the three components to shape Congifuration, margin, and elevation Texture Dry, moist, or mucoid (capsules) Surface appearance smooth, rough, dull, wrinkled, shiny Pathogen microorganism that causes disease Opportunistic pathogen can cause disease in right circumstance Inoculation implantation of microorganisms on or in media Culture cultivation of the microorganisms, what has actually grown Bacteria colonies smaller shinier more numerous Mold colonies defuse (larger) fuzzy Aseptic Technique No contaminating microorganisms are introduced into culture or culture materials Microbiology is not contaminated by culture that are being manipulated Pure culture technique 1. Mix of cells in sample 2. Separation of cells by spreading or dilution on agar medium 3. Growth increases the number of cells 4. Microbes become visible as isolated colonies containing millions of cells How do you calculate total magnification Ocular magnification x objective magnification What is the relationship between working distance and magnification? Working distance decreases as magnification increases field of view what you are looking at What is the relationship between field of view and magnification magnification increases as field of view decreases Resolving power quantifiable means of measuring the ability of a lens system to resolve detail Chromogenesis production of a color pigment usually via enzyme activity Opacity amount of light transmitted through Opaque (opacity) none Translcuent (opacity) some Transparent (opacity) almost see through Pigmentation is influenced by media, temperature, time Enzyme affects organisms metabolism Low temperature microbistatic Low temperature effects on organisms Reduces Rnx rate membrane fluidity decreases can denature proteins usually doesn't kill slows down high temperatures microbicidal High temperature effect on organisms denaturation destruction of lipids (archaea and enzymes used in PCR) Thermostability ability to maintain structure and or function at high temperatures Psychphiles really cold 5-15C Mesophiles 15-45C (human pathogens) Thermophiles 45-80 (Compost heap) Hyper thermophiles 80C (hot springs, archaea) Psychotrophs 5-30C Food preservation refrigerate 40C freeze Disease mesophiles microenviroments human Clostridium botulinum spores toxic produced by vegetative cells Release of acetylcholine from motor neurons Flacid paralysis Respiratory failure Obligate Aerobes needs oxygen Aerobic respiration Micraerophiles stomach 2-10% Aerobic respiration at lower levels Facultative Anaerobes Can use oxygen but does not need it can grow in absence of O2 Aerotolerant Anaerobes indifferent to O2 O2 does not kill it Obligate fermentor obligate Anaerobes (chlostritium) O2 is toxic will kill it does not use O2 Anaerobic respiration Fermentation Fluid thioglycollate medium (FTM) rich liquid + a little bit of agar thioglycollate reduces oxygen to water Rasazurin dye pink in O2 Methylene blue blue in presence of O2 White in absence of O2 Lethal effects of light on bacteria sterilizes surfaces lethal effects due to mutagenetic properties 260nm (max killing) Why is UV most effective at killing bacteria 260nm DNA absorbs the most pyrimidine dimers Microcaccus Lubous obligate aerobe Serratia marcessens facultative anaerobe Enterococcus farcalis facultative anaerobe alcaligenes faccalis obligate aerobe Costridium sporogenes obbligate anaerobe Aerobic respiration O2 used as a terminal electron acceptor converted to H2O H2O2 is a by-product oxidizing agent damages RNA, DNA, proteins What do anaerobes and aerotolerant anaerobes lack catalase