Micro Final Essay Questions

Front 1

mention of each step of the process, with explanation of what is going on (brief explanation of each step). DNA code = T A C T T A C C G A G A T T C T T G T T T A T CmRNA code =

Back 1

mRNA code = A U G A A U G G C U C U A A G A A C A A A U A G• Transcription - making nMRA from DNA via RNA polymerase • mRNA contains uracil rather then thymine for complimentary base pairing• Base Pairing T-A, C-G A(DNA) - U(mRNA)

Front 2

What steps in protein synthesis are inhibited by each drug?Cipro -Erythromycin - Acyclovir -

Back 2

Cipro - inhibits transcription - no DNA replication Erythromycin - formation of polypeptide chainsAcyclovir - uses DNA polymerase to inhibit synthesis of DNA and RNA

Front 3

Which drug is more effective against bacteria? Why?

Back 3

Erythromycin - INHIBITS PROTEIN SYNTHESIS in GRAM POSITIVE only and not eukaryotes

Front 4

Which drug is more effective against viruses? Why?

Back 4

Acyclovir - inhibits protein transcription so viral DNA can not replicate without effecting host cells - Nucleoside analog- 100x greater affinity for viral than cellular polymerase

Front 5

Which drugs will have effects on the host's cells? Why?

Back 5

Acyclovir - targets viruses which use host cells to replicate. Inhibits DNA synthesis which occurs in host cells and attached virus

Front 6

Use the index to identify the disease for which acyclovir is used. Why is it more effective than erythromycin for treating this disease?

Back 6

genital herpes- false guanine nucleoside - stops protein synthesis and DNA replication - More effective - disease caused by virus - Erythromycin kills bacterial cells not affective - harmful

Front 7

Why did the use of DNA polymerase from the bacterium Thermus aquaticus allow researchers to add the necessary reagents to tubes in a preprogrammed heating block (PCR)?

Back 7

Taq Polymerase stable at high temps - 72 degrees• Added for extension of DNA synthesis• Can read template strand and match to complementary nucleosides rapidly. Application: PCR copies DNA - allows for AIDS to be detected in early stages

Front 8

The G-C content of Micrococcus is 66-75 moles %, and of Staphylococcus, 30-40 moles %. According to this information, would you conclude that these two genera are closely related? Explain your answer.

Back 8

No; Difference of more that 10% • 66-30= 36 and 75- 40= 35% = 35-36% > 10% so - not related• (G-C + A-T = 100%)

Front 9

Describe the use of a DNA probe and PCR for: a. Rapid identification of an unknown bacterium.

Back 9

DNA Probe - give us library of known bacteria to compare unknown bacteria to on plate• PCR - allows for replication and isolation of one strand of DNA to match to DNA probe

Front 10

Describe the use of a DNA probe and PCR for: b. Determining which of a group of bacterium are most closely related

Back 10

DNA Probe - allows us to match enzymes from sample to determine molecular %• PCR - allows for replication and isolation of one strand of DNA to match to DNA probe

Front 11

Place each phylum in the appropriate category. Typical gram-positive cell wall

Back 11

Firmicutes (except Mycoplasmatales), Actinobacteria, Euryarchaeota

Front 12

Place each phylum in the appropriate category. o Typical gram-negative cell wall

Back 12

proteobacteria, Mycoplasmatales - only in firmicutes phylum, Chlamydiae, Spirochaetes, Bacteroidetes, Crenarchaeota, Spirochaetales, Cyanobacteria, chloroflexi, chlorobi, Fusobacteria

Front 13

If bacteria stain gram positive - what is their G+C like?

Back 13

High

Front 14

Place each phylum in the appropriate category. o No peptidoglycan in cell wall

Back 14

Chlamydia

Front 15

Place each phylum in the appropriate category. o No peptidoglycan in cell wall

Back 15

Mycoplasmatales

Front 16

After contact with a patient's spinal fluid, a lab technician developed fever, nausea, and purple lesions on her neck and extremities. A throat culture grew gram-negative diplococci. What is the genus of the bacteria?

Back 16

Genus name - Neisseria meningitidisMeningococcal (meningitis) - symptoms are same as technician's symptoms and is gram negative

Front 17

Define and describe, in reference to the lifecycle of the liver fluke Clonorchis sinensis, the intermediate host and definitive host. Also name the phylum and class that this animal belongs to.

Back 17

Phylum -Platyhelminthes (parasitic flatworms)• Class-Trematoda• two intermediate hosts: carry the immature form of the parasite and are necessary for the parasites lifecycle1. freshwater snail - lays eggs and grows inside snail body 2. parasitically bore into wide variety of fish, in which metacercariae are encysted. • Definitive host: acid resistant cyst- Avoids digestion so it can reach intestine then liver to eat bile

Front 18

A girl developed generalized seizures. A CAT scan revealed a single brain lesion consistent with a tumor. Biopsy of the lesion showed a cysticercus. The patient lived in South Carolina and had never traveled outside the state. What parasite caused her disease? How is this disease transmitted? How might it be prevented

Back 18

Taenia solium; - tapeworm that is obtained from consuming undercooked pork. • Transmission - consumption of undercooked meat, touching or drinking dirty water. • Prevention - Thoroughly cook meat, sanitation, avoid dirty drinking water (usually found in foreign countries)

Front 19

Discuss the arguments for the classification of viruses as living organisms.

Back 19

contain DNA or RNA and a protein coat (capsid) • undergo replication by creating multiple copies of themselves. • Biology define "living organism" as one that autopoetic or "self-producing"

Front 20

Discuss the arguments against the classification of viruses as living organisms.

Back 20

No enzymes for energy production or protein synthesis they insert their DNA into another living host cell self-replicating aspect of viruses cannot actually be carried out unless attach to a host cell cannot reproduce outside living cells

Front 21

A 40-year-old male who was seropositive for HIV experienced abdominal pain, fatigue, and low-grade fever (38°C) for two weeks. A chest X-ray examination revealed lung infiltrates. Gram and acid-fast stains were negative. A viral culture revealed the cause of his symptoms: a large, enveloped polyhedral virus with double-stranded DNA. What is the disease? Which virus caused it? Why was the viral culture done after the Gram and acid-fast stain results were obtained?

Back 21

disease: CMV virus: Cytomegalovirus Gram/ aid fast stains negative - not bacterial. since stains negative- virus suspected (cannot see viruses with light microscope)- viral culture to determine which virus

Front 22

List the experimental requirements of Koch's postulates, and explain the exceptions to the requirements.

Back 22

same pathogen must be present in every case of disease.Tetanus - unequivocal symptoms2. The pathogen must be isolated from the diseased host and grown in pure cultureException: Syphilis - can't be isolated and grown in lab3. The pathogen from the pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal.Exception: HIV - only in humans4. The pathogen must again be isolated from the inoculated animal and must be shown to be the same pathogen as the original organism.Exception: pneumonia and nephritis are caused by multiple organisms

Front 23

Cancer patients undergoing chemotherapy are normally more susceptible to infections. However, a patient receiving an antitumor drug that inhibited cell division was resistant to Salmonella. Provide a possible mechanism for the resistance.

Back 23

The antitumor drug was a genetically altered form of salmonella • Targets cancerous cells and prevents replication by binary fission • Salmonella bacteria multiply through cell division which drug inhibits - therefore no salmonella contraction.

Front 24

Describe the mode of action of each of the following antibiotics and explain what effect each one may have on host cells. Give an example of an organism that would be effectively treated for each drug; Penicillin

Back 24

Penicillin - inhibits synthesis of cell wall 1. Effects bacterial cells - not the host -animals and human cells - no cell wall2. Staphylococcus aureus

Front 25

Describe the mode of action of each of the following antibiotics and explain what effect each one may have on host cells. Give an example of an organism that would be effectively treated for each drug; Indinavir

Back 25

Indinavir - inhibits HIV protease1. Host cell - antiviral - protects host cells2. Treats HIV

Front 26

Describe the mode of action of each of the following antibiotics and explain what effect each one may have on host cells. Give an example of an organism that would be effectively treated for each drug; Erythromycin

Back 26

Erythromycin - binds to 70S ribosome inhibiting protein synthesis1. Host cell - can kill gram negative host cells minimally2. Treats Treponema pallidum

Front 27

Describe the mode of action of each of the following antibiotics and explain what effect each one may have on host cells. Give an example of an organism that would be effectively treated for each drug; polymyxin B

Back 27

polymyxin B - causes membrane leakage, - cationic detergent 1. No effect on host cells 2. Treats Salmonella enterica