Microbiology Lecture Unit 2

Acute Animal Viral Replication Stage

1. Attachment to specific host cells via receptor on host cell membrane EX: HIV uses an envelope to bind to CD4 on T helper membranes 2.Penetration (entry): 2 mechanisms: 1-pinocytosis: virus is engulfed by cell membrane EX: rubella 2-fusion: viral envelope fuses with host plasma membrane EX: chicken pox 3.Uncoating: viral capsid is removed and viral genome exposed, most viruses must uncoat before replication, transcription, and translation, can use own or host's enzymes 4.Biosynthesis: DNA: may use hosts enzymes replication in nucleus transcription in nucleus translation in cytoplasm assembly in nucleus RNA: must carry own enzymes replication in cytoplasm transcription in cytoplasm translation in cytoplasm assembly in cytoplasm no nucleus, no central dogma 5.Assembly and Release: capsomere join together to cover genome, naked viruses wait by plasma membrane for host cell to degrade, releasing viruses en masse, enveloped viruses continue to bud from plasma membrane

What are the two types of RADIATION used in sterilization, and how do they work?

1. Ionizing Radiation: <1nm wavelength Makes an H2O molecule ionize to form hydroxyl free radicals, damages DNA, membrane organelles EX: gamma rays, x rays 2. Non Ionizing Radiation: >1nm wavelength Less penetration energy than ionizing radiation, UV light: 260 nm wavelength, causes thymine dimers, distorts DNA, leads to errors in DNA replication, cell death

Be able to draw a typical bacterial growth curve (see Figure 6.15) and describe what is occurring in each of the 4 stages. Be sure to label your axis properly!

1. Lag Phase: no cell division, increasing metabolic activity, DNA replication, protein synthesis, cells adjusting to new environment 2. Log Phase: exponential growth, division at fastest rate, cells most metabolically active, and vulnerable to injury and control methods 3. Stationary phase: growth slows then stops, cells begin to die as nutrients and space decrease, toxic byproducts of metabolism increase 4. Death phase: viable cell numbers quickly decline for reasons in phase 3

Bacteria Growth Curves

1. Lag phase: no cell division, increasing metabolic activity, DNA replication, protein synthesis, cells adjusting to new environment 2. Log phase: exponential growth, division at fastest rate, cells most metabolically active and vulnerable to injury and control methods 3. Stationary phase: growth slows then stops, cells begin to die as nutrients and space decrease, toxic byproducts of metabolism increase 4. Death phase: viable cell numbers quickly decline because of stationary pahse

Helminths

2 Phyla: 1. Platyhelminths: flat worms, digestive systems are incomplete (1 hole) or not exist, often have multiple hosts and stages usually hermaphroditic 2. Nematoda: round worms, have complete digestive systems (2 holes), usually only have 1 host, adults are dioecious, female worms are larger 2 classes: 1. Trematodes: flukes, leaf shape at one stage in life, have suckers for attachment to host, usually require intermediate hosts(snails), hermaphroditic, incomplete digestive systems EX: Schistosoma (bladder or liver fluke): humans infected when larval forms cecariae, swim from water to skin, disease of poverty and poor sanitation 2. Cetsodes: Tapeworms, contracted from undercooked meats, infect GI, grow meters long, Not serious, scolex (head) has suckers that hook to attach, proglottids are hermaphroditic, most mature proglottid furthest from head is full of eggs EX: Taenia sp. T. saginata: beef, usually asymptomatic, mild T. solium: pork, much worse, cysts can decelop in human brain, can lead to neurological issues like stroke Nematodes: roundworm EX: Enterobius (pinworm), preschool aged kids, oral/fecal transmission, perianal itching

Know the groups of organisms based on their response to oxygen. What cellular enzymes are present/absent in each of these groups? (see Table 6.1)

Aerobes: obligate or strict, require oxygen for growth EX: fungal, human Microaerophile: aerobes that require a decreased O2 and increased CO2 EX: Campylobacter Anaerobes: obligate or strict, can't grow in presence of O2 EX: Clostridium, NO SOD OR CATYLASE Facultative: can grow with or without O2 EX: E. coli

Be able to name the 2 special culture containers used to isolate ANAEROBES and MICROAEROPHILES. Be able to sketch the growth patterns of each of the four oxygen groups in sodium thioglycollate broth

Anaerobes: anaerobic cultivation- brewer's jar, removes ALL O2 Microaerophiles: microaerophile cultivation- candle jar, decreases O2, increases CO2 see table 6.1 for broth sketches

Know how the term ANTIPARALLEL relates to DNA structure.

Anti Parallel: If the DNA sequence starts with 5', then it ends with 3'; If it starts with 3', then it ends with 5'; 3' end has free OH hydroxyl, 5' end has free PO4 phosphate

Know the differences between the following ASEXUAL SPORE types found in fungi: arthrospores, chlamydospores, sporagiospores, conidiospores, blastospores.

Arthospores: thickened fragments of septate hyphae Chlamydospores: rounded swollen section of septate hyphae Sporagiospores: spores encased in a protective sack Conidiospores: chains of spores with no protective sack Blastoconida: multiple buds off parent cells

Be able to describe the types of SEXUAL and ASEXUAL REPRODUCTION which occur in protozoans.

Asexual: through mitosis, offspring identical to parents, 3 forms: 1- Fission: cytoplasm splits into equal halves 2-Budding: smaller daughter cells produced 3-Schizogeny: multiple nuclear divisions without cytoplasmic divisions, multinuclear cells Sexual: requires meiosis, allows genetic variability, recombination and change 2 types: 1-Conjugation: insertion of micronucleus into another cell, fusion to form zygote, cytokinesis 2-Gametocytes: gamete cells, haploid cells, fuse with opposite sex mating type to form zygotes

Be able to describe how enveloped viruses are released from their host cells.

Assembly and Release: capsomere join together to cover genome, naked viruses wait by plasma membrane for host cell to degrade, releasing viruses en masse, Enveloped Viruses continually bud from plasma membrane

Be able to describe each of the following stages in ANIMAL VIRUS infection: attachment, penetration (=entry), uncoating.

Attachment: to specific host cells via receptor on host cell membrane Penetration: 2 mechanisms 1. Pinocytosis: virus is engulfed by cell membrane 2. Fusion: viral envellope fuses with host plasma membrane Uncoating: viral capsid is removed and viral genome is exposed, most viruses must uncoat before replication(DNA/RNA), transcription(mRNA) and translation(proteins)

What size filters are used to remove bacteria versus viruses from liquids?

Bacteria: 0.22 μm- 0.45 μm Viruses: 0.01 μm

CH. 6: MICROBIAL GROWTH Be able to define: bacterial growth, generation time.

Bacterial Growth: increase in bacterial cell numbers through process of binary fission Generation time: time required for bacterial cells to divide

Know how BINARY FISSION is different than mitosis. Why are logarithmic/exponential scales rather than arithmetic scales used to graph bacterial growth?

Binary Fission: enables bacterial populations to reach huge numbers asexually, mitosis results in two daughter cells Arithmetic scales: do not show the population changes in the early stages of the growth curve Logarithmic scales: shows each stage of bacterial growth with a curve

Be able to compare and contrast the BIOSYNTHESIS stage (replication, protein synthesis, and assembly) in DNA vs RNA viruses.

Biosynthesis: DNA: may use host enzymes replication in nucleus transcription in nucleus translation in cytoplasm assembly in nucleus RNA: must carry own enzymes transcription in cytoplasm translation in cytoplasm assembly in cytoplasm

What are buds? How are fungal spores different from bacterial spores? What is a dimorphic fungus?

Buds: asexually produced by mitosis, mother yeast can produce 24 daughter cells Fungal Spores: Asexual spores produced by mitosis, and sexual spores produced by myosis Bacterial Spores: allow a bacterial cell to survive adverse environmental conditions Dimorphic fungus: two forms of growth, can grow as either a mold or a yeast, produce vegetative hyphae

What is the CENTRAL DOGMA of molecular biology? How might the steps be different in prokaryotes and eukaryotes?

Central Dogma: describes how DNA is transcribed to messenger RNA, which is translated into proteins that carry out vital cell functions Prokaryotes: DNA undergo replication and transcription and RNA undergo translation in same place Eukaryotes: DNA undergo replication and transcription in the nucleus, while RNA undergo translation in the nuclear membrane

Be able to define and give examples of each of the following types of culture media: chemically defined, complex, selective, differential, both S&D.

Chemically defined: exact composition is known, costs lots of money, for fastidious organisms only EX: E. coli Complex: enzymatic digest of plants or meats, exact composition varies EX: NA, TSA Selective: allow only a few types of bacteria to grow EX: Bismuth sulfite agar, Salmonella Differential: most will grow, some with distinctive appearance EX: blood agar Selective and Differential: combined in a single medium EX: EMB (Eosin, Methylene Blue) and MacConkey: selective for Gram -, differential for lactose fermentation

CH. 8: MICROBIAL GENETICS Know the definitions for: CHROMOSOME, GENE, PHENOTYPE, GENOTYPE, TRIPLET CODE.

Chromosome: structures containing DNA that physically carry hereditary information, contain the genes Gene: segments of DNA that code for functional products Phenotype: actual, expressed properties, such as the organisms ability to perform a particular chemical reaction; the manifestation of the genotype Genotype: the organism's genetic makeup, all it's DNA, and the information that codes for all the particular characteristics of the organism Triplet Code: set of rules that determines how a nucleotide sequence is converted into the amino acid sequence of a protein

For the PLATYHELMINTHES, list their general characteristics, classes, pathogenic examples given in lecture. What is the difference between intermediate and definitive hosts? Be able to give two examples of intermediate hosts from the textbook. Know the diseases and transmission modes for the human pathogens.

Classes of Platyhelminthes: 1: Trematodes- flukes, leaf shaped at one stage in life, have suckers for attachment to host, usually require intermediate hosts (snails, crayfish), hermaphroditic, incomplete digestive system EX- Schistosoma (bladder or liver fluke): humans infected with larva forms cercariae, swim from water to skin, poverty and poor sanitation 2: Cestodes- tapeworms, contracted from undercooked meats, infect GI, grow meters long, not serious, scolex (head) has suckers, hooks to attach, segments hermaphroditic, most mature proglottid farthest from head is full of eggs, one species produces cysts in human brain tissue EX- T. saginata- beef, usually asymptomatic, mild EX- T. solium- pork, much worse, cysts can develop in human brain, can lead to neurological issues Intermediate hosts: the parasite that undergoes asexual reproduction Definitive hosts: harbors the sexually reproducing stage

Be able to define: codon, anticodon, start codon, stop codons, reading frame, polyribosome, redundancy. What are the roles of the 3 special sites on the ribosome discussed in class (A-site, P-site, E-site)?

Codon: the language of mRNA, groups of three nucleotides such as AAA GGC and AUG Anticodon: a sequence of three bases that is complimentary to a codon, each tRNA has one Start Codon: sense codons, code for amino acids Stop Codons: nonsense codons, UAA, UAG, UGA, signal the end of the protein molecules synthesis Reading Frame: AUG sets Polyribosome: a cluster of ribosomes linked together by a molecule of messenger RNA and forming the site of protein synthesis Redundancy: there are more than 1 codon for each amino acid 3 Special Sites: EPA sites P and A sites: allow tRNA to H bond with mRNA E sites: cause tRNA to exit

Be able to describe the following means of horizontal genetic transfer in microbes: CONJUGATION, TRANSDUCTION, TRANSFORMATION, TRANSPOSITION.

Conjugation: genetic material is transferred from one bacterium to another, requires direct cell to cell contact, conjugating cells must be of opposite mating type Transduction: genetic transfer between bacteria, bacterial DNA is transferred from a donor cell to a recipient inside a virus that infects bacteria called bacteriophage Transformation: genes are transferred from one bacterium to another as naked DNA in solution, showed that genetic material could be transferred from one bacterial cell to another Transposition: small segments of DNA that can move from one region of a DNA molecule to another

Know the functions of the following structures found in Protozoans: cytosome/ oral groove, storage vacuoles, anal pores, macronucleus, micronucleus, cyst, trophozoite.

Cytosome: mouth Storage Vacuoles: stomach Anal pores: Excrete wastes Macronucleus: the larger type of nucleus in ciliates Micronucleus: small nucleus that forms when a fragment of a chromosome is not incorporated into one of the daughter nuclei during cell division Cyst: thick walled, dormant, protected, designed for survival outside the host Trophozite: motile, metabolically active, have soft pellicle, no cell wall

Make a list of the major families of DNA and RNA viruses described in lecture and give an example disease caused by each.

DNA viruses: 1. papoviridae: DNA virus; HPV 2. poxviridae: DNA virus; smallpox 3. herpesviridae: DNA virus; HSV, chickenpox 4. herpnadoviridae: DNA virus; Hepatitis B RNA viruses: 1. picornaviridae: RNA virus; polio, cold, Hepatitis A 2. calicivirdae: RNA virus; norovirsu (flu) 3. togaviridae: RNA virus; encephalitis, rubella 4. flaviviridae: RNA virus; dengue fever, Hep C, west nile 5. coronaviridae: RNA virus; SARS, common cold 6.rhabdoviridae: RNA virus; rabies 7. orthomyxoviridae: RNA virus; influenza 8. retroviridae: RNA virus; HIV, AIDS

Using the genetic code given in Figure 8.8, complete ALL PARTS (a-i) of question #4 on page 236 in the textbook (12th edition)

DNA: 3' ATATTACTTTGCATGGACT mRNA: 5' UAUAAUGAAACGUACCUGA tRNA: 3' AUAUUACUUUGCAUGGACU Amino Acid: Methainine (AUG)

Be able to describe the basic structure of DNA, RNA and PROTEINS.

DNA: nucleic acids made of nucleotide monomers, deoxiribose, double stranded, complimentary pairs AT and GC, hydrogen bonds hold these pairs together, single/double stranded circular chromosome and plasmids, complimentary strands are antiparallel RNA: ribose instead of deoxiribose, uracil instead of thymine, single stranded, 3 types (mRNA- messenger, rRNA- ribosomal, tRNA- transfer) Proteins: composed of amino acids linked together by covalent peptide bonds, 3 letter symbols for all 20 amino acids, tertiary structure, shape of protein required for function

What is DECIMAL REDUCTION TIME and how can it be used to compare organisms?

Decimal Reduction Time: the time in minutes in which 90% of a population of bacteria at a given temperature will be killed, can compare organisms by their heat resistance

What are some methods of measuring BACTERIAL CELL NUMBERS discussed in lecture? Know how to calculate the number of bacteria that would result after a given number of generations in culture.

Direct counts: microscopic counts with a hemocytometer Plate counts: macroscopic colony counts after a serial dilution Turbidity: spectophotometer measures amount of bacteria block light transmission in liquids Calculation: # cells(start) X 2^n = # cells(end, after n generations)

Know how FUNGI are classified. Know the characteristics and examples given for the following Phyla of fungi: Zygomycota, Ascomycota, Basidiomycota, Deuteromycota (Anamorphs)

Fungi: classified by sexual spore types 4 sexual spore types: 1. Zygomycota: conjugation fungi, sacrophylic, live off decaying matter, EX- rhizopus 2. Ascomycota: sack fungi, often dimorphic EX- aspergillus, histoplasma, trichophyton 3. Basidiomycota: club fungi EX- cryptococcus 4. Anamorphs: completely asexual, but related to ascomycota by RNA genes EX- fungi imperfecti (candida, coccidiodes, pneumocysts)

CH. 12: PARASITOLOGY Know the vegetative (non-reproductive) structures found in yeasts and molds: hyphae, mycelium, pseudohyphae.

Hyphae: long filaments of cells joined together, microscopic cell chains Mycelium: macroscopic mass of hyphae Pseudohyphae: short chains of unseparated cells

Define: persistent (= chronic) viral infection, latent viral infection. Give 2 examples of each.

Latent Viral Infection: viral DNA in provirus state EX: chickenpox becomes shingles Chronic Viral Infection: constant infectious carrier state EX: hepatitis B&C

Are low temperatures and desiccation bacteriocidal or bacteriostatic? Which organisms are resistant to these control methods?

Low temperatures: Bacteriostatic, pathogenic bacteria is resistant Desication: Bacteriocidal, viruses are resistant

Be able to classify microbes into three principle groups on the basis of their preferred temperature range. Give an example environment where you would encounter these organisms.

Mesophiles: "middle loving" (10-50 degrees C), human pathogens, well known Psychrophiles: "cold loving" (-10-30 degrees C), deep oceans, glaciers Thermophiles: "heat loving" (40-110 degrees C), hot springs, volcanoes, archeobacteria

What are MUTATIONS? How frequently do they occur spontaneously? Be able to give an example of a chemical and physical mutagen.

Mutations: a change or mistake in a DNA nucleotide sequence Spontaneous error rate: 1 mistake per 1 billion nucleotides Chemical Mutagen: nitrous acid Physical Mutagen: electromagnetic radiation (X-Rays)

For the NEMATODES, list their general characteristics and the pathogenic examples given in lecture. For the pathogens, know the disease caused and transmission mode.

Nematodes- roundworms, cylindrical, taped at each end, males smaller than females EX- Enterobius- pinworm, preschool aged kids, oral/fecal transmission, primary symptom: perianal itching, scotch tape ID EX- Ascaris- 1/3 humans infected worldwide, asymptomatic, migrate out anus, nose, umbilicus, 16 inch adults, eggs in feces, oral/fecal transmission (dirty water) EX- Hookworms, 20% humans worldwide, chronic, causes severe anemia, transmitted by larva in soil, enter skin of bare feet EX- Trichinella, very rare, 1% humans, mild disease, causes inflammation of eyes, nails, digestive tract, transmitted by improperly cooked pork with encysted larval worms

Oxygen Requirements

Not all microbes require O2, some are harmed by it *don't need examples on exam* 4 microbial groups based on response to oxygen: 1. AEROBES: obligate or strict, require oxygen for growth, sits at top of vile -enzymes in cells for detoxification EX: fungal, humans 2. MICROAEROPHILE: aerobes that require decreased O2, increased CO2, sits in middle of vile -small amounts of catalase and superoxide dismutase EX: ampylobacter 3. ANAEROBES: obligate or strict, can't grow in presence of O2, sits at bottom of vile -neither catalase nor superoxide dismutase EX: clostridium 4.FALCULATIVE: can grow with or without O2, moves throughout vile -catalase, superoxide dismutase EX: E. coli Candle Jar: candle jar decreases O2, increases CO2 Brewer Jar: brewer's jar removes ALL O2 Sodium thioglycollate: reducing media used to determine oxygen requirements of bacteria, O2 is only present on surface

What is an ORIGIN of replication? What is a replication FORK? Know which enzymes are involved in replication and their functions as described in lecture. Be able to define: LEADING STRAND, LAGGING STRAND, SEMI-CONSERVATIVE REPLICATION, OKAZAKI FRAGMENT.

Origin: site on chromosome where replication starts Ds DNA separate and new DNA strands synthesized that are complimentary to old strands Replication fork: 2 forks move away from the origin bidirectionally 5 ENZYMES: 1. DNA Helicase: unwinds parent DNA strands 2. DNA Polymerase: builds new DNA strands that are complimentary to the old strands; daughter strand grows in 5->3 direction and new nucleotides are added to 3'OH end only; 2 types of daughter strands are leading strand : made directly into the fork lagging strand: made in pieces (Okazaki fragments: about 1000 nucleotides) 3. RNA Polymerase: (primase) begins by making short DNA pieces called primers, primers are later replaced with DNA nucleotides by DNA polymerase 4. DNA Ligase: bonds okazaki fragments together 5. DNA Gyrase: (topoisomerase) relaxes supercoiling at replication forks, drugs like ciprofloxacin work by interfering with gyrase and halt bacteria replication only Semi Conservative Replication: each new double stranded DNA contains one original (conserved) strand and one new strand

Be able to define: osmotic pressure, isotonic, hypotonic, hypertonic, halophile, acidophile.

Osmotic pressure: concentration of dissolved solutes in a liquid (ex: salt, sugar, protein) Isotonic: after immersion of a cell, osmotic pressure is equal across the cell's membrane, same concentration Hypotonic: a solution that has a lower concentration of solutes than in an isotonic solution Hypertonic: a solution that has a higher concentration of solutes than in an isotonic solution Halophile: organism that requires a high salt concentration for growth Acidophile: bacterium that grows below pH 4

What is a PHAGE? Describe the following types of infections: lytic, temperate (=lysogenic), latent. What is a plaque? What is the difference between generalized and specialized transduction?

Phage: viruses that infect bacteria Lytic Phage: lyse their host cells, leave plaque on lawns, keep DNA separate from host cell genome Temperate Phage: less destructive, don't always lyse host cells, integrate DNA into host chromosome, viral DNA replicates along with host cell DNA, may become lytic, allows for transduction, lysogenic phage similar to latent infections Latent Infection: animal viral genome becomes integrated into host chromosomes, not cleared by host immune system, latent state is called proviral state Plaque: open spaces on lawn of pea tree dish, where bacteria have been killed by virus and no bacteria is left Generalized: can take any piece of the bacterial chromosome Specialized: always takes the same piece of DNA or gene when it leaves the host cell

Look at Table 7.8 and notice the mode of action (how it works) and examples of the following chemical control agents: Phenolics, Biguanides, Halogens, Alcohols, Heavy Metals, Surfactants, Food Preservatives, Aldehydes, Ethylene Oxide, Peroxygens.

Phenolics: Triclocin, derivatives of phenol (anesthetic), contain a molecule of phenol that has been chemically altered to reduce it's irritating qualities or increase it's antibacterial activity in combination with soap or detergent Halogens: effective microbial agents, particularly iodine and chlorine Alcohols: effectively kill bacteria and fungi but not endospores or nonenveloped viruses Heavy Metals: biocidal or antiseptic, exert antimicrobial activity Surfactants: can decrease surface tension among molecules of a liquid Food Preservatives: added to food to retard spoilage Aldehydes: most effective antimicrobials, form covalent cross links with several organic functional groups on proteins Ethylene Oxide: a surface disinfectant widely used in hospitals Peroxygens: oxydizing agents, antiseptic

Be able to define: point mutation (=base substitution), silent mutation, missense mutation, nonsense mutation, frameshift mutation, knockout mutation.

Point Mutation: a single base at one point in the DNA sequence is replaced with a different base Silent Mutation: No change in final protein Missense Mutation: the base substitution results in amino acid substitution in the synthesized protein Nonsense Mutation: a base mutation resulting in a nonsense codon, stop codon created that produces an abnormally short product protein Frameshift Mutation: one or a few nucleotide pairs are deleted or inserted in the DNA Knockout Mutation: a mutation that is lethal to the cell, literally knocks the cell out, nothing gets translated properly

What is a PRION? How do they cause disease? How are they transmitted? Know which human diseases are associated with prions.

Prion: infectious proteins, not viruses, no nucleic acid Cause disease: cause normal proteins in nervous tissue to fold abnormally, lead to vacuoles in brain tissues Transmitted: food consumption Human diseases: kuru, Creutzfeldt-Jakob disease, Gerstman-Straussler-Scheinker syndrome, fatal familial insomnia

Protozoa (5 phyla & disease examples)

Protozoa: used to be classified by motility, now is classified by rRNA 1. Amoeboza: move via pseudopodia EX: Entamoeba histolotica: causes dysentry, by oral/fecal, eats tissues, rbcs, patients become anemic and dehydrated 2. Archaeozoa: move using flagella, lack mitochondria EX: Trichomonas vaginitis: causes vaginitis for females, urethritis for males EX: Giardia lamblia: causes diarrhea 3.Ciliates: motile by cilia, most free living, only one pathogen EX: Balantidium coli: causes dysentry 4. Euglenozoa: have flagella and mitochondria EX: Euglena: photosynthetic EX: Trypanosoma: hemoflagellate causes african sleeping sickness and chagas disease 5. Apicomplexa: not motile, obligate intracellular parasites, have very complex life cycles, each species has a different disease, vector, and geography EX: Plasmodium: etiological agent for malaria, kills nearly 1 million people a year, mosquitos are vector

How are PROTOZOANS classified today? How did they used to be classified? Know the characteristics and examples given for the following phyla of protozoans: Archeozoa (Diplomonads/Parabasalids), Amebae, Apicomplexa, Ciliates, Euglenozoa. Know the diseases and transmission modes for the pathogens

Protozoans today: rRNA Protozoans back then: motility 5 phyla: 1- Amoebozoa: move via pseudopodia EX- Entamoeba histolotica- causes dysentry, by oral/fecal, eats tissues, rbcs, patients become anemic and dehydrtaed 2- Archaeozoa: move using flagella, lack mitochondria EX- Trichomonas vaginitas- causes vaginitis (F) and urethritis (M) EX- Giardia lamblia- causes diarrhea 3- Ciliates: motile by cilia, most free living, only one pathogen, EX- Balantidium coli- causes dysentry 4- Euglenozoa- have flagella and mitochondria, each species has a different disease, vector, geography EX- Euglena: photosynthesis EX- Trypanosoma- hemoflagellate causes african sleeping sickness and chagas disease 5- Apicomplexa- NOT motile, obligate intracellular parasites, have very complex life cycles EX- Plasmodium- etiologic agent for malaria, kills 10 million people every year, mosquitos as vector

CH. 13: VIROLOGY Be able to describe the following general characteristics of VIRUSES: size, metabolism, genome, host range.

Size: most are extremely small (0.2-0.02 microns) Metabolism: not true cells, obligate intracellular parasites Genome: can be DNA or RNA, single or double stranded, circular or linear, in one or many chromosome pieces Host range: most viruses are species specific, exception: rabies and influenza, most viruses are tissue/cell specific, requires virus to bind to receptors

Be able to give 5 examples of organisms which are relatively resistant to chemical control methods.

Spore formers- C diff Myobacteria - weird cell wall Prion type of infection Pseudomonis - gram negative porin structure Naked virus- stomach flu

CH.7: CONTROL OF MICROBIAL GROWTH Be able to define: sterilization, disinfection, antisepsis, degerming, sanitation, germicide, bacteriostasis, sepsis.

Sterilization: the removal or destruction of all living microorganisms Disinfection: control directed at destroying harmful microorganisms Antisepsis: treatment directed at a living tissue Degerming: the mechanical removal, rather than the killing, of most of the microbes in a limited area Sanitation: intended to lower microbial counts to safe public health levels and minimize the chances of disease transmission from one use to another Germicide: kills microorganisms, -cide means kill Bacteriostasis: to stop or to steady, inhibit the growth and multiplication of bacteria Sepsis: indicates bacterial contamination, presence of pathogens in blood

Which MICROBIAl cell structures are the targets of most antimicrobial agents?

Target: a microorganism's plasma membrane, because it actively regulates the passage of nutrients into the cell and the elimination of waste from the cell, so damage to the plasma membrane cause cellular agents to leak into the cell

What are the temperatures, times, and pressures used for the most common dry and moist heat methods of MICROBIAL CONTROL. Define: TDP.

Temperature: 121°C Times: 15 minutes Pressure: 15 psi TDP: Thermal Death Point: lowest temperature at which all organisms in a particular liquid suspension will be killed in 10 minutes

ESSAY Central Dogma

The sequence of nucleotides in DNA determine the sequence of amino acids in a protein. Founded by Francis Crick Sequence: DNA-> RNA-> Protein Replication: each double stranded DNA molecule contains an original strand, and one new strand, they rewind and reproduce a new strand Transcription: the synthesis of a complementary strand of RNA from a DNA template Translation: decoding the language of nucleic acids and converting it to the language of proteins Prokaryotes: in transcription a strand of mRNA is synthesized using a portion of DNA, and stores the genetic info in the sequence, DNA undergo replication and transcription and RNA undergo translation in same place Eukaryotes: DNA undergo replication and transcription in the nucleus, while RNA undergo translation in the nuclear membrane

What is TRANSCRIPTION? What is a PROMOTER REGION? Which ENZYME is required in transcription? What is the TEMPLATE STRAND? What is the TERMINATOR REGION?

Transcription: synthesis of a complementary strand of RNA from a DNA template Promoter Region: the site where transcription begins and RNA polymerase binds to the DNA RNA Polymerase: required enzyme in transcription Template Strand: a template for synthesis of a complementary RNA transcript Terminator Region: site on DNA where RNA polymerase reaches when it is finished with RNA synthesis

What is TRANSLATION? What are the three types of RNA, and how are they involved in making proteins?

Translation: protein synthesis, involves decoding the language of nucleic acids and converting it to the language of proteins Three types of RNA: mRNA: messenger, carries the coded information for making specific proteins from DNA to ribosomes where proteins are synthesized rRNA: ribosomal, forms and integral part of ribosomes, the cellular machinery for protein synthesis tRNA: transfer, molecules both recognize the specific codons and transport the required amino acids

What is a vector? Name 2 protozoan and 2 helminth diseases requiring vectors.

Vector- an arthropod that carries disease causing organisms from one host cell to another Protozoan: Plasmodium/Malaria (mosquitos), Trypanosoma (tsete flies) Helminth: Schistosoma (larval worms), Enterobius (pinworm)

Be able to describe the basics of viral structure, including their capsid, envelope, and morphologies. How can viruses be cultured in the lab?

Viral structure: all have protein coat, some have lipid envelope with glycoprotein spikes for attachment, without envelope called naked Morphologies: 1. Helical (rod shaped) ex: tobacco mosaic virus 2. Polyhedral (many sided) ex: polio 3. Enveloped (roughly spherical) ex: influenza 4. Complex (bacteriophages) In lab: cant grow in media alone, require specific cells to replicate in

How can viruses cause cancer? Define: proto-oncogene, oncogene. Be able to list the example viruses associated with specific human cancers from lecture.

Viruses cause cancer: -most are DNA viruses or retroviruses -most integrate viral genome into host DNA -some viruses carry oncogenes - some viruses insert into host proto oncogenes -cancerous cells are transformed Oncogenes: mutant genes that promote unchecked cell growth Proto oncogenes: normal genes that cause cell division and growth Cancer causing viruses: HPV, hepatitis B&C, EBV, HSV8

Know the differences between the following SEXUAL SPORE types found in fungi: zygospores, ascospores, basidiospores.

Zygospores: encased in a thick, spiny structure, formed around diploid zygote Ascospores: found in a sack or pod like structure called an ascus Basidiospores: found under the fruiting structure (cap) of mushrooms

Know the formula for pH and what it means. Define: basic, acidic, neutral.What type of microbes are most likely to spoil acidic foods and why? Why are buffers added to most media?

pH formula: -Log10 [H+] Basic- above 7 Acidic- below 7 Neutral-7 Microbes: fungi prefer acidic conditions, so they spoil acidic food Buffers: added to growth media to maintain pH