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Microbiology TAMU Exam 1
Microbial Ecology - CORRECT ANSWER-part of ecosystem bacteria recycle carbon, nutrients, sulfur and phosphorus that can be used by plants and animals use photosynthesis- ocean/freshwater to produce energy- make carbon compounds which serve as a food source, bottom link of food chain Bioremediation - CORRECT ANSWER-process that used naturally occurring or genetically engineered microorganisms What does bacteria do in bioremediation? - CORRECT ANSWER-degrade organic matter in sewage or detoxify pollutants such as oil and mercury outcome: detoxify/reduces toxicity What are some examples of bioremediation? - CORRECT ANSWER-few species of bacteria (pseudomonas sp.) can use crude oil for energy, cleaning up oil spills in ocean What is a real life example of bioremediation? - CORRECT ANSWER-April 20, 2010 BP oil spill in Gulf June- scientist sample oil blume at 3600 ft below surface, 100x, find oil degrading August- short chain hydrocarbons gone, bacteria still more damaging long chain carbons present, study these bacteria- identify their oil by degrading enzymes microorganisms - CORRECT ANSWER-organisms that are too small to be seen with an unaided eye microbes in our lives - CORRECT ANSWER-<1% pathogenic decompose organic waste produces by photosynthesis industrial chemicals fermentation outnumber us What are some eukaryotic cells? - CORRECT ANSWER-fungi, protozoans, algae What are some prokaryotes? - CORRECT ANSWER-bacteria, viruses(not a cell) What word describes that microbes are everywhere, all around us? - CORRECT ANSWER-they are ubiquitous What is an example of a microbe? - CORRECT ANSWER-polar bear hairs are hollow in warmer weather- microorganisms, algae & cyanobacteria gets in hair and turns it green
What did they use on the gulf? - CORRECT ANSWER-used dispertants/absorbant booms, sink down oil globs, more surface area for bacteria to break it down Bioremediation of Landfills - CORRECT ANSWER-300 metric tons of trash and waste deposited into environment each yr.
- successful remediation needs microbes/bacteria + H2O + O
- ground water, which is the primary source of drinking for many is often polluted Waste management by Bioremediation - CORRECT ANSWER-use of microbes to breakdown or remove toxic wastes in water and soil, uses pesticides reduced by 96% solvents reduced from 1 million ppb to <10pph, heavy metals detoxified How to microbes interact with plants? - CORRECT ANSWER-they make nitrogen available to plants N2- not form that can be used by most organisms
- bacteria can metabolize N2-NO2 & NH4 (ammonia)
- these forms can be used by nitrate plants
- ???? How do microbes aid in the digestive process of grazing animals? - CORRECT ANSWER-bacteria in gut breakdown cellulose to usable compounds in animals, produce necessary enzymes Microbes as biopesticides - CORRECT ANSWER--bacillus thurginiensis(bacterium)- toxic to insects that that ingest them, produces spores and crystals, insects ingests crystal- activated and breaks down digestive tract, harmless to other organisms, found in commercial dusts, chops caterpillar up on inside Biotechnology - CORRECT ANSWER-use of microbes to produce foods and chemicals, is centuries old
- fermentation processes
- industrial processes
- medical uses-making insulin
- milk being coagulated by rennin, forming curd, bacteria for flavor and acidity Microbes synthesize antibiotics - CORRECT ANSWER-natural metabolic product of bacteria/fungi, releasing antibiotics into surroundings
- bacteria with penicillin mold circle at bottom (pic on ppt. 1, slide 22)
- competition to protect themselves from other organisms Recombinant DNA technology - CORRECT ANSWER--enables bacteria and fungi to produce a variety of proteins for vaccines and enzymes, drugs
- missing of defective replaced in gene therapy (viruses)
- Genetically modified bacteria are used to protect crops from insects from freezing
- death w/in 2-4 days of first symptoms Jewish Population during Plague - CORRECT ANSWER-escaped plague's devastation b/c of biblical cleanliness laws, kept rats w/ bacteria out of their house Spanish Flu Pandemic of 1818 - CORRECT ANSWER-killed w/in hours
- lung hemorraging=drawn in fluids
- 30 - 40 million dead Outbreaks Today - CORRECT ANSWER-H1N1-Swine Flu, Ebola,Zika Differences today - CORRECT ANSWER-we know what causes disease, how disease spread and how to fight disease spontaneous generation - CORRECT ANSWER-abiogenesis(a=not) the hypthesis that living organisms arise from non-living matter-> frogs jump out of mud, mice jump out of hay, rains->earthworms in puddles a "vital force" forms life Biogenesis - CORRECT ANSWER-the hypothesis that living organisms arise from pre- existing life
- humans->humans
- recognize bacteria (microbes) were living & cause diseases about 200 yrs. - > Germ Theory of Diseases Francisco Ready 1668 - CORRECT ANSWER-one jar closed with meat- no maggots one jar open- maggots hatching into flies Results: flies lay eggs, keep flies away-> biogenesis, flies had to be there first Anton Van Leeuwenhoek 1632- 1723 - CORRECT ANSWER--used microscope, thought about microorganisms, described them
- dutch, maker, lens specimen on pin, etc. pond water
- his single-lens magnified up to 300x
- published findings of microorganisms to Royal Society 1676
- microbes moved w/purpose=animaculus=living
- father of bacteriology-introduced bacteria to society
- could spontaneous generation be true for microorgansims?
- wouldn't tell people about microscope because he wanted his work to be accredited to himself Con-Loyis Jablot 1670s - CORRECT ANSWER-french boiling-stop food storage covered broth, uncovered broth nutrient in broth in flask, heated not sealed(cloudy)->microbial growth nutrient in broth sealed-> no microbial growth concluded-spontaneous generation
John Needham (1740s) - CORRECT ANSWER-heated nurtient broth in covered flasks both sealed, heated time pases-> microbial growth, cloudy, vital forces came together to produce microbes where did microbes come from?
- endospores, spontaneous generation
- sealed poorly
- not heated enough
- during sealing Lazzaro Spallanzani - CORRECT ANSWER-Italian Priest, boiled nurtients in flasks, sealed broth-> no microbial growth-> biogenesis.
- Needham agrued that he destroyed vital forces by boiling, it was too harsh
- Spallanzani responded by saying the unsealed flasks had microbial growth Joseph Priestly - CORRECT ANSWER--discovers oxygen in 1774
- now necessary to have air in all experiments
- not must allow air in Theodore Schwann 1836 - CORRECT ANSWER-air passes through flame-heated tube before flask Franz Schultz 1836 - CORRECT ANSWER-air goes through harsh chemicals before flask (in tube)
- treated air too harshly. destroyed vital forces Schroeder and Von Dusch-Germans - CORRECT ANSWER-air passed throgh cotton plug before entering flask
- results: no bacterial growth-> biogenesis
- spontaneous generation issue still not settled, vital forces not destroyed Louis Pasteur 1822- 1895 - CORRECT ANSWER--placed nutrient solution in flasks
- created flasks w/ long, curved necks
- boiled solutions let microbes be exposed to air
- bacteria couldn't make their way up or down, how could be prove bacteria growing, behind tube to prevent microbial growth
- 1861 - demonstrated microorganisms are present in air
- nutrient broth placed in flask, heated, neck broken-microbial growth
- nutrient broth placed in flask, heated, neck didn't break-no microbial growth fermentation and pasteurization - CORRECT ANSWER-pasteur showed that microbes are responsible for fermentation
- microbial growth is also responsible for spoilage of food
gelatin- good for isolation of colonies, bu there were problems, gelatin melted easily, many bacteria digested this gelatin Fannie Heis - CORRECT ANSWER-wife of Koch's assistant
- suggested we use agar
- agar- melted in boiling water, cooled to 40C before hardening, doesn't melt again until 80C, no degraded Richard Petri-Koch's Lab - CORRECT ANSWER-developed petri dish
- allowed isolation of pure cultures
- stimulated progress in bacteriology Development of Techniques for studying microbial pathogens - CORRECT ANSWER- Koch's work led to discovery or development of:
- nutrient broth and nutrient agar
- methods for isolating microorganisms
- agar
- petri dish Immunology - CORRECT ANSWER-study of immunity
- vaccines and cell products are being investigated to prevent and cure all viral diseases Edward Jenner 1798 - CORRECT ANSWER-used a vaccination procedure to protect individuals from small pox small pox - CORRECT ANSWER--high mortality rate
- small portion to be protected for life
- cow pox protected against small pox- similar disease, very mild
- exposed boy to cow pox, inoculate, and save them from cow pox
- inoculate whole body
- very infectious
- immune for life, if you survive
- used cow pox vaccinium virus as vaccine against small pox- used by barius virus
- largest and most complex human disease virus then
- stopped vaccinating in 1972
- last natural case small pox 1977 (natural spread from one person to another) When was small pox eradicated? - CORRECT ANSWER- 1979 - 1st disease to be eradicated & only human disease, done using vaccines-> protected us from a lot of deadly diseases Do parasitic diseases have vaccines? - CORRECT ANSWER-no parasitic disease has a vaccine against it. ex. Malaria- 60+ yrs. working on it Z repositories of variola virus-CDC in US/Russia
What was small pox used as? - CORRECT ANSWER-a bioterrorism agent
- highly infectious
- low infective dose Birth of Modern Chemotherapy - CORRECT ANSWER--treatment w/ chemicals
- chemotherapy agents used to treat infectious disease can be synthetic drugs of antibiotics Antibiiotics - CORRECT ANSWER-chemicals produced by bacteria and fungi that inhibit or kill other microbes
- have laboratory manipulated antibiotics Alexander Flemming 1928 - CORRECT ANSWER-discovered first antibiotic-actually working with staphylococcus from wound infections
- observed that penicillin fungus made the antibiotic penicillin that killed staphylococcus aureus 1940s - CORRECT ANSWER-penicillin was tested clinically and mass produced
- used in WWII for soldiers would infections Prokaryotes - CORRECT ANSWER--bacteria/archae
- one circular movement, not in a membrane
- no nucleus
- no histones->histonee like proteins
- no organelles
- bacteria-peptidoglycan (complex cell wall),cell walls
- archea- pseduomembrane, cells walls
- binary fission
- I circular double stranded DNA smaller cells Eukaryotes - CORRECT ANSWER-all other cells
2 linear double stranded DNA makes up chromosomes
- paired chromosomes in nuclear membrane->in nucleus
- histones
- organelles
- polysaccharide simple cell wall
- mitotic spindle very compact, meiosis, mitosis
- animals do not have cell wall (prok. plants, fungi and archea do) large cells bacterial cells - CORRECT ANSWER-differ in size, shape, arrangement
- clumpy vs. chains
- rods, chains
- spirroceats, curved rods- swim in circular motion, 500 um (micrometers) in length w/o microscope
- S. agalactae 3um
- made of rRNA and protein saving units
- site of protein sythesis
- prok. ribosome are 70s-sedimentation rate
- 2 sub units: prok. 30s+50s=70s euk. 40s+60s=80s larger inclusions/granules/vesicles/vacuoules - CORRECT ANSWER-store compounds when nutrients are abundant then utilized when nutrients are scarce
- polysaccharides granules, lipid inclusions, sulfur granules, energy reserves gas vacuoles - CORRECT ANSWER-protein covered cylinders
- allow bacteria to change boyancy in H2O
- food sources
- O
- temperature
- light purified PHB - CORRECT ANSWER-possesses many of the same properties of plastic made from petroleum products:
- melting point.
- crystal structure
- molecular weight
- strength
- biodegradable! *put compounds into inclusions to reduce osmotic pressure-store extra problems w/o proteins w/ osmotic pressure The nuceloid - CORRECT ANSWER-contains circular, ds DNA, lacks membrane (prok) Plasmids - CORRECT ANSWER-circular, double stranded DNA, not part of chromosome (outside of nuceloid region)
- replicate in clap of chromosome
- inherited-passed on to all progeny
- not required for host growth & replication What do plasmids do? - CORRECT ANSWER-give bacteria a selective advantage
- genes (DNA) code for proteins= give new abilities to cell What new abilities to they give to cell? - CORRECT ANSWER-toxin- more pathogenic enzyme-drive metabolic pathways/different types of energy source, new compound, breakdown antibiotics, resist or grow in an environment, fight off antibiotics in other ways, block entry for example.
- new defense mechanisms. new metabolic abilities
Cytoskeletons - CORRECT ANSWER-thought prok. lacked these, but in 1990s found that they originated in prok.
- actin and tueblin of the euk. cytoskeleton are homologous w/ some bacterial proteins MReB & FtsZ respectively) what are the functions of the cytoskeleton? - CORRECT ANSWER--internal scaffolding
- helps in cell division
- helps in building cell wall
- as a contractile environment for swimming How are bacteria identified? - CORRECT ANSWER-based on cell wall structure, 2 types are identified using gram stain technique. Periplasmic Space - CORRECT ANSWER-not discernable
- contains loose network of Peptidoglycan-cell wall material
- periplasm-gelica
- active area of metabolism
- transport proteins
- pathogenic gm(-)=lytic virulence factors
- 20 - 80nm lytic virulence factors - CORRECT ANSWER-collagenases- builds tissues hyaluronidases-breaks down cell content by hydrolyaic acid proteases- break down proteins b. lactamase- breaks down some antibiotics gram (-) cell wall - CORRECT ANSWER-two different layers, both very thin, cell wall is 3 - 8nm, then periplasmic space inbetween and then 1-3nm other side prokaryotic plasmids - CORRECT ANSWER-like paired chromosomes they are cellular ds DNA replicate independently of chromosomes byt are inherited by the daughter cells can enhance host by producing a new metabolic pathway prokaryotic enzymes - CORRECT ANSWER-involed in metabolic pathways, build up or block down collagenase- break down collagen, tissues, allows entry of bacteria into tissues
- collagen- builds tissues Prokaryotic Periplasmic Space - CORRECT ANSWER-area between cell membrane and peptidoglycan
- this is not usually present in gram (+)
- size of pps in gram (-) ranges from 30 to 71nm which accounts for 20-40% of the cell volume
- more of a gel than a fluid filled space, substance is periplasm. - > filled with PG, various proteins (enzymes), various molecules to be secreted, it is an active area of metabolism
Gram (-) outer membrane - CORRECT ANSWER-protection from phagocytes, host proteins and antibiotics has liposaccharide with 3 parts also has an extra layer of protesion=overall what are the three parts of the lippo saccharide? - CORRECT ANSWER-O polysaccharide (antigen) any subastance that alerts the system core polysaccharide-made of unusual S ligans (-) charge lipid A- is an endotoxin, toxic part of the LPS moleucle, emdedded in outer membrane, only released upon lysis functions of LPS/ outermembrane
- confers (-) charge
- LPS stabalizes outermembrane creates personality barrierm more permeable than cell membrane, a permeability layer outer membrane is an extra layer of protoskelteon=overall - CORRECT ANSWER-gram (-) bacteria are more resistant to environment factors/drugs/chemicals
- proins (proteins) form channels through membranes-associate as trimers(timers?), can change pore size, different channel sizes Braun's Lipoproteins- most prominent protein in the outermembrane, connects the OM to the PG layer=stabilizes the cell wall of gram (-) overall gram(-) bacteria have a more complex Cell Wall. The gram stain mechanism - CORRECT ANSWER-1. crystal violet (primarily dye)
- Gram Iodine- mordant-> intensift the dye by binding to the cell to cell wall
- alcohol decolonizer
- safranin (red dye counter-stain)
- bacteria cells are all (-) charged
- crystal violet & Safarin are cationic (+) charged all stains based on cell wall structure gram stains with gram (+) - CORRECT ANSWER-shrinks down peptidoglycan, trap dye gram stains with gram (-) - CORRECT ANSWER-strips liquid so dye escapes Glycocalyx - CORRECT ANSWER-outside cell wall usually sticky capsule: neatly organized extracellular polysacchardie-> to host fcells to enter structures slime layer- unorganized loose, not required slime layer - CORRECT ANSWER-not required for bacterial survival-> if present-> advantage it prevents phagocytosis-> WBC engulfment protect against dessication-> contains alot of H20-> raises persistance exluceds bacteriophages (viruses attack bacteria) block viruses
exclude hyrdophobic toxic substances-> toxins, drugs, detergents aids in bacterial attatchment to host-> raises ability to invade overall=virulence factors-> high phthogenicity and persistance, ability to ??? bacteria increased do not require a capsule- avirulent appendages (prok.) - CORRECT ANSWER-external projectoins from the cell body two major groups:
- motility- flagella & axial filaments
- attatchment flagella - CORRECT ANSWER--motility 3 parts: filament filament attatched to protein hook filament - CORRECT ANSWER-outside cell wall, up to 20nm in dimension, anchored to Cell Wall by basal body made up of chains of flagellin (protein) filament attatched to protein hook - CORRECT ANSWER-flexible coupling, flagella to rotate hook anchored to cell wall and cell membrane by basal body - CORRECT ANSWER- gram (-) have 4 rings 60 cell lengths gram (+) have 2 rings .100,000 rpms for seconds rotate 360 degrees like a propellor-> prok, rotate counter clockwise and clockwise, euk. only rotate counter clockwise motile cells - CORRECT ANSWER-rotate flagella in different directions at different speeds, rotate flagella to run or tumble move toward or away from stimuli (taxis) chemotaxis (chemicals) phototaxis (light) counterclockwise rotation=run clockwise rotation= tumble/turddle axial filaments - CORRECT ANSWER-motility, also called endoflagella
- in spirochetes anchored at one end of the cell twists around the rod wi/in the periplasmic space b/w cell membrane and cell wall rotation causes cell to move ex. trepohema paccillum causes syphillis
- spirochete- burrows through tissues gram (-) and rods
Endoplasmic Reticulum - CORRECT ANSWER-cytoplasm is permeated with an irregular network of branching and twisting membranes tubules and many flattened sacs called cisternae this network of tubules and cisternae is the endoplasmic reticulum Rough Endoplasmic Reticulum - CORRECT ANSWER-orginates from outermembrane of nuclear envelope extends in a continuous network through cytoplasm , can go all the way through to the cell membrane rough due to ribosomes architecture permits transports of materials from: nucleus - > cytoplams-> cell membrane ribosomes are made in nulceus, transported through nuclear envelopes, cytoplasm produces proteins, free ribosomes or attatched to RER, cell membrane is part of cell membrane or secreted ribosomes used in cytposlam- enzymes, etc. in Euk. cells - CORRECT ANSWER-nucleus is mebrane bound nuclear envelope- outermembrane-> periplasmic space-> inner membrane, nuclear envelope gaps= nuclear pore, out come mRNA & ribosomes, proteins into tubulues, traffic to surface to golgi apparatus, to cell membrane and surface Smooth E.R - CORRECT ANSWER-closed network w/o ribosomes functions in:
- synthesis
- processing
- transport
- storage (of non proteins nucleus i.e. lipids/polysacharides) overall: transport-proteins, lipids, other materials through cell synthesis-proteins by ER, associated ribosomes and non proteins, such as lipids, by smooth ER golgi appartaus (euk) - CORRECT ANSWER-stack of flattened sacs- cisternae closely assocaited with ER in structure and function transitional vesicles- from RER contain proteins= undergo modification in golgi + lipids=lipporteins+polysac.=glycoprotein secretory vesicles(released from golgi)- transported modified protiens to organelles as secretory proteins to the cell membrane golgi makes lysosomes- vesivles fufel enzymes i.e. lysozyme other cells breakdown nutriendts phag-> use lysosomes their enzymes to digest invadors CM-> settle proteins, lysosome Ribosomes - CORRECT ANSWER-function: protein sythnesis
80S (larger than prok) 2 subunits 40s + 60s free ribosomes= sites of synthesis for non secretory and non membrane protines E.R ribosomes- made proteins for transport to cell membrane and secretion 70S in chloroplasts & mitochondria 70S The eukaryotic nucleus - CORRECT ANSWER-repository for cells genetic info most prominent organelle of euk cell bound by nuclear envelope 3 parts- a complex structure, inner membrane, periplasmic space, outermembrane chromosomes wrapped around histones (spooly), keeps from tangling bacteria-> 1 chromosome at most nucleoles - CORRECT ANSWER-it is a seperate organelle even though its not membrane bound playes a major role in ribosome synthesis-> RNA model and is a collection of ribosome sununits the ribosome sub units are transported through nuclear pores into cytoplasm cell wall - CORRECT ANSWER-plants, algaem fungi carbohydrates despite their chemical makeup, euk cell walls are chemically simpler, less complext than prok. PG glycocalyx - CORRECT ANSWER-if a cell wall is present, it is on the cell wall if not, carbohydrates extending from plasma mebrane, bonded to proteins and lipids in membrane flagella (euk-some cells) - CORRECT ANSWER-covered with a membrane, long shafted cylinders containing microtublues in a 9+2 arrangement covered by an extension of the cell membrane 10x thicker than prok. flagella motillity is??? one euk. microtubules in flagella= is same size as bacterial flagella how long are euk. flagella - CORRECT ANSWER- 100 - 200um in length how long are prok. flagella - CORRECT ANSWER- 5 - 20nm in length cillia - CORRECT ANSWER-9+2 & covered with membrane similar in overall structure, but shorter and more numerous found only on a single group of protozoa and certain animal cells (in our respiratory tract) functions in motility, feeding, filtering move in a wave like fashion
