Ch. 19 Viruses & Bacteria: What Is a Virus?questions).pdfCh. 19 Viruses & Bacteria: Define virus. What are viruses? Define and translate bacteriophage. Review virus composition. What

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Ch. 19 Viruses & Bacteria:Define virus. What are viruses?Define and translate bacteriophage.Review virus composition. What two classes of compounds are found in all viruses? Define capsid.Identify the capsid in this diagram.

Describe the viral MO in three words.Generally, how do different viruses compare in size and structure?

What Is a Virus?

What are the two primary functions of the capsid?

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Head

Tail sheath

DNA

T4 Bacteriophage Influenza Virus

RNA

Membrane envelopeTail fiber

RNA

Capsid proteins

Capsid

Surface Glycoproteins

Tobacco Mosaic VirusHow are viruses classified?

What is the first level of viral classification? Define host range.Identify the host range of each example. How widely does host range vary?What is the second level of viral classification? Identify the GM of each example.

Note the variety of size, shape, complexity and accessories in these examples.

What is the third level of viral classification?Define retrovirus.What is the forth level of viral classification?

What is the source of the membrane envelope? Function of surface glycoproteins?

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Viral InfectionDescribe how viruses “trick” the cell into allowing it inside?In general, what happens once the viral GM is inside?Specifically, what two possible modes or pathways may infection take? What does this depend on?

Compare & contrast lytic vs. lysogenic infection?What is the most important difference between them?Define virulent virus.Which mode of infection do virulent viruses use?Define temperate virus.Which mode of infection do temperate viruses use? Define latent period.

Define prophage.

What triggers a prophage to leave the host chromosome and be expressed?

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Study the diagram showing the mode of HIV infection.

What is HIV's classification?

HIV

Is HIV virulent or temperate? How do you know?What is the latent period of the HIV provirus without treatment?

Identify this cell.What is this cell's general function?

Refer to the diagram to describe each step of HIV infection.Explain what designates HIV as a retrovirus.When, in relation to cells, did viruses probably appear on Earth? Explain why.Where did they come from or from what did they develop?

Do viruses evolve? How do you know?Which viruses evolve most quickly and why?

Do viruses spontaneously generate today? Where do “new” viruses come from?

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Pandemic

How do viruses cause disease? (HIV, zika)Does viral infection always produce disease?Can antibiotics be used to treat viral infection? Why?What are used to prevent viral infection? How do vaccines work?

Viral Disease in Humans

What's the drawback?Can anything be used to prevent viral disease following infection? What's the drawback?What is the difference between an epidemic and a pandemic?What is one virus/disease that the World Health Organization wiped off the face of the Earth (almost)? How did they do it? Why can't we do the same for all viruses?

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Viruses produce serious __________ diseases including foot-and-mouth disease. Many viruses infect ___________ and pose a serious threat to many crops.

Other than human disease, how else do viruses affect us?

Ebola: Nausea, vomiting, diarrhea (may be bloody), red eyes, raised rash, chest pain and cough, stomach pain, severe weight loss, bleeding, usually from the eyes, and bruising (people near death may bleed from other orifices, such as ears, nose and rectum)

Viral Diseases

(ssRNA)

(ssRNA)

(ssRNA)

(dsDNA)

(dsDNA)

Zika Fever, rash, joint pain, red eyes, microcephaly in newborns(ssRNA)

(ssRNA)

Ebola(ssRNA) Hemorrhagic fever (see left)

Identify the diseases for which there are vaccines.What determines which viruses we are able to develop vaccines for?Why?

Study the table...

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Viroids

Viroids are bare single-strand RNA loops of around 300 nucleotides. They do not code for protein. The simplest of infectious agents, viroids may be similar to the first virus-like particles.

Identify the general host range of viroids.Compare & contrast viroid and virus structure.How do viroids usually enter their host? Why? What effect do they have on their host?Study the experiment diagram... Identify the compounds that end in “ase”.

What does each enzyme do in this experiment? (Same as the Avery experiment.)What is in each test tube along with the enzyme? What is the purpose of “no treatment”?

What do blotches on the leaves represent? What do these results suggest?

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Prions

Identify the general prion host range.Compare & contrast virus, viroid & prion structure.How is prion disease transmitted? Why? What effect do they have on their host?Study the diagram... Identify and describe initial prion formation. Describe “recruitment”.Describe the formation of amyloid plaques. Define & determine the effect of fractionation.Identify two diseases caused by prions.Study the photo... Identify the normal brain vs. the prion infected brain.

At this time, what is the only absolute diagnosis?

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Bacteria

Review the type of cell bacteria are.Review the size bacteria are relative to eukaryotic cells.How common and abundant are bacteria relative to other organisms?How were all prokaryotes once classified?

Identify the two prokaryotic Kingdoms.Identify the two prokaryotic Domains.

Which prokaryotic Domain and Kingdom are represented in the photo?How do you know?

Determine and describe the importance of bacteria in the biosphere.

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Peptidoglycan Cell MembraneRibosomes

PiliDNAFlagellum

Cell Wall

Identify the Domain, Kingdom and species this diagram represents.

Classifying Prokaryotes: Eubacteria

How do you know?Review and add the functions of each structure labeled in the diagram.

Draw an additional membrane layer outside the cell wall and label it “Outer Membrane”.Do all bacteria have an outer membrane? What is it made of? What is its function?

How do Eubacteria compare to Archaebacteria in terms of diversity and habitat?Where can Eubacteria be found?

Use a bracket to label the nucleoid region. How is this different than a nucleus?

Draw in and label at least one plasmid. What is it and how does it function?Label the cytoplasm. What is it? Do all cells have it? Why?

Draw a thicker layer outside the cell wall and label it “Capsule”.Do all bacteria have a capsule? What is it made of? What is its function?

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Classifying Prokaryotes: ArchaebacteriaHow do Archaebacteria generally compare to Eubacteria in their outward appearance?

What is different about Archaea cell walls?What is different about Archaea plasma membranes?What is different about Archaea genes?

What are Methanogens and where do they live?What are Halophiles and where do they live?

What are Thermophiles and where do they live?

How can we tell them apart?

Why do they have these differences?

With which Domain are their genes similar?What does this suggest?

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Identifying Prokaryotes: Eubacteria

What is needed to see prokaryotes?Is it easy to identify different species visually? Why?What characteristics do microbiologists use to identify different species or strains?Identify and label the three major shapes shown in these micrographs.

Identify and label the procedure shown in the diagram. What does it determine?

How can looking at living Eubacteria using a light microscope help distinguish them?. What can be altered or measured in cell culture to distinguish them?

What is the difference between Gram + and Gram – bacteria?Explain how is this information would be useful to doctors attempting to cure a bacterial infection?Which is the most effective means of distinguishing bacterial species or strains?...

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Identifying Prokaryotes: Metabolic Diversity

Mycobacterium tuberculosis

CyanobacteriaDeep Oceanic Vent Tube Worm Bacteria

Identify and define the two mater handling modes of prokaryote metabolism.Are these designations strictly prokaryotic? How do you know?

In general, describe the level of prokaryote metabolic diversity and infer why this is so.

Define metabolism.Identify the two general requirements to sustain life.

Combine, list and define the 4 modes of metabolism that represent prokaryote diversity. Match each example above with one of the four combined modes.

Identify your own mode of metabolism! Plantae? Fungi? Protista?

Identify and define the two energy handling modes of prokaryote metabolism.

Identify the two processes prokaryotes utilize to break down food molecules and convert energy for cellular work...

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Bacteria in liquid cultures.

Identifying Prokaryotes: Metabolic Diversity

Define aerobic cellular respiration.Define aerobic.Define anaerobic fermentation.Define anaerobic.

Study the diagram… Identify the representation of test tubes, liquid culture medium, the air-medium interface, and bacterial cells.Explain the distribution of bacteria in each culture.

Define obligate.Define facultative.

Are these the same species or strains of bacteria? How do you know?Identify and label each culture combining the terms you defined.

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Prokaryote Growth and Reproduction

Identify the general process taking place in this micrograph.

Describe in your own words how this happens.Which type of reproduction is this?

Define and describe prokaryotic binary fission.At this point, it is still one cell. What is it called?What are the two cells resulting from the split called?

How will the two daughter cells compare to each other and the parent cell?Will the daughter cells grow?

What is the advantage of this type of reproduction? Disadvantage?What are two ways this disadvantage is overcome?...

Will the parent cell still exist?

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Prokaryote Genetic Recombination

Identify the general process taking place in this micrograph.

Describe in your own words what is happening.

Is this a form of reproduction?

Define and describe prokaryotic conjugation.

What kind of genetic information may be transferred?How will the two cells compare afterward?

What is the advantage of these processes for prokaryotes?

Disadvantage for humans and other species?

How do you know?What is the observable difference between these cells?

In which direction is the transfer?

Review bacterial transformation.Define bacterial transduction.

What is the advantage of these processes for humans?

What part of the genome is transferred?

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Prokaryote Survival & Dispersal

Identify and label the endospores in these micrographs.What do they contain? What surrounds them?When do they form? What happens to the rest of the cell?Define dormant? How long can they remain dormant?When do they return to activity?Explain the primary purpose of endospores.Explain a secondary purpose.

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Importance of Bacteria

Identify and explain four ecological roles for bacteria in the biosphere?Draw and label these roles on this food web diagram.Other than being able to live within their system, how are they useful to us?

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Importance of Bacteria in the Nitrogen Cycle

Rhizobium nodules on a legume.

Study the diagram... Identify the only organisms able to incorporate atmospheric N2.

To which organisms is nitrogen important? Why? (Review)What percentage of Earth's atmosphere is nitrogen?

Define nitrogen fixation.Identify the other general role bacteria play in the cycle.Explain the general importance of nitrifying bacteria.

Define legume. Identify the relationship this is an example of.

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Importance of Bacteria to Humans

Breyers Light Probiotics Plus Yoghurt contains an added dose of live, active Bifidobacterium yogurt culture.

Use the images on this slide to identify and list ways prokaryotes are important to us.

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19-3 Diseases Caused by Bacteria and Viruses

Bacterial pathogens Of the 20 bacterial phyla currently recognized, thirteen are not present in this figure due to the absence of noteworthy pathogens. Some of these missing phyla are relatively important, like the Cyanobacteria.

Generally, where can you find bacteria and viruses in nature?Generally, how many cause disease?Define pathogen. In general, how do pathogenic bacteria cause disease?...

Prokaryotic Diversity

Identify this type of diagram. Generally, what does it show?Study the diagram while reading the caption.

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Bacterial DiseasesStudy the diseases and symptoms in this table...Identify, list and explain two ways bacteria produce these symptoms.Define bacterial exotoxin.Define bacterial endotoxin.

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Bacterial Disease in Humans

A vaccine is made from an antigen isolated or produced from the disease-causing microorganism. The vaccine is injected into the blood stream. Macrophages patrolling tissues recruit Killer T-cells which go to work to remove the threat. B-cells in the blood stream, with the help of helper T-cells, respond to the antigen by producing antibodies. The antibodies bind to the antigen to "neutralize"or inactivate it. In addition, memory cells are produced and remain ready to mount a quick protective immune response against subsequent infection with the same disease causing agent.

Are there vaccines that protect against bacterial pathogens? Define vaccine.Explain how vaccines work.Define immunity.

Study the diagram while reading the caption.

Identify the component of the immune system responsible for imparting immunity.

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Effects of different antibiotics on growth of a Bacillus strain. The right-hand image shows a close-up of the novobiocin disk (marked by an arrow on the whole plate). In this case some individual mutant cells in the bacterial population were resistant to the antibiotic and have given rise to small colonies within the zone of inhibition.

Determining Antibiotic Sensitivity

Study the diagram while reading the caption. Define antibiotic.

Define antibiotic resistance. Review how bacteria may become resistant. Define antibiotic sensitivity.When is it most likely a bacterial population will be sensitive to a particular antibiotic?Based on these results, which antibiotics should be used?

Which disk in the sensitivity screening is the control? What is likely on it?

How do you know?

Define zone of inhibition.

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Controlling Bacteria

A hamburger patty cooked to 160 °F, regardless of color, is safe.

Use the images on this slide to identify and list ways prokaryotes can be controlled. Include the effect each method has on bacteria.