Microbiology Introduction

Question 1

What are prions?

Answer 1

aggregates of proteins that have mutated somehow and cause some trouble in the body

Question 2

What is an obligate intracellular pathogen?

Answer 2

pathogens that require other cells to multiply

Question 3

What are the main differences between prokaryotes and eukaryotes?

Answer 3

prokaryotes have fewer organelles, no nucleus, and a cell wall

Question 4

What are some aspects of bacteria that are targetable by drugs/medications?

Answer 4

peptidoglycan in the cell wall (not present in people), ribosome is slightly smaller than human ribosome

Question 5

What are some different classes of microbes?

Answer 5

Prions, Viruses, Bacteria, Fungi, Protozoa, Helminths

this list is organized by size.

Question 6

what are helminths?

Answer 6

“worms” like roundworms, tapeworms. visible to the eye, eukaryotes

Question 7

What limits bacterial growth?

Answer 7

Nutrients, space, disease

Question 8

What are different forms of horizontal gene transfer in bacteria?

Answer 8

Phage Transductance - virus will infect bacteria, multiply, leave bacteria, infect new bacteria cells. But! Virus sometimes picks up bacterial DNA instead of viral DNA and will pass the bacterial DNA to the newly infected DNA.
Transformation - passive transfer of DNA by picking
Conjugation - direct transfer of plasmids by contact between bacteria

Question 9

What type of genetic material do plasmids contain?

Answer 9

Plasmids usually contain extracellular genetic information that you don’t “need” to function but that add to the functions of a cell. Bacteria will have additional virulence factors or antiobiotic resistance or toxins in plasmids.

Question 10

What are - sense RNA viruses?

Answer 10

Negative sense RNA viruses are viruses which bring along the opposite strand of RNA that they need to create proteins. So they need to bring along reverse transcriptase or an RNA-dependent RNA polymerase to create the complement and create the proteins.

Question 11

What are + sense RNA viruses?

Answer 11

Positive sense RNA viruses are able to have their proteins translated immediately by the host cell

Question 12

What organelles do viral genes make? What organelles do viruses take advantage of in the host cell?

Answer 12

viruses only have genetic code for regulating the host cell and making their protein coat and organizing everything into a cluster. they do not have genetic code for making mitochondria, or ribosomes, or plasma membranes. They steal all of this from the host cell.

Question 13

What type of polymerases are available naturally in human cells?

Answer 13

DNA-dependent DNA polymerase

DNA-dependent RNA polymerase

Question 14

Are viruses with lipid envelopes more or less stable than viruses with just a protein coat?

Answer 14

Less stable! If the lipid membrane is dessicated (dissolved), they lose their infectious factors and aren’t able to infect host cells anymore. They just become blobs of DNA or RNA in a protein shell. Protein only viruses have the infectious factors on their protein coat which is much more robust.

Question 15

How does a virus infect a cell?

Answer 15

Viruses recognize target cells by interacting with extracellular receptors. The cell will either be tricked into letting the virus in, the virus will force itself in, or the virus (phage is a virus that infects bacteria) will inject its genetic material. The protein coat dissolves and the viral genome is replicated. The virus eventually takes over the cell, re-assembles its protein coat, and breaks free of the cell

Question 16

What is reverse transcriptase?

Answer 16

an enzyme used to generate complementary DNA (cDNA) from an RNA template. This DNA is then replicated by the host cell and eventually transcribed/translated into protein

Question 17

What does - sense RNA viruses need to bring with it into a new host cell?

Answer 17

needs to bring an RNA-dependent RNA polymerase or a reverse transcriptase enzyme! Otherwise it can’t start the multiplication process.

Question 18

What types of genetic information can be found in viruses?

Answer 18

RNA, DNA. Single Stranded RNA (+ or -) double stranded RNA

Question 19

What is a naked virus?

Answer 19

A virus with just a protein coat

Question 20

What are three factors that influence the spread of infectious diseases?

Answer 20

Efficiency of transmission
Duration of infection
Number of people exposed per event.

Question 21

What are the steps of an infection?

Answer 21

Host encounters pathogen. Pathogen enters host. Pathogen infects host cells. Pathogen multiplies. Pathogen damages host tissues. Someone wins (unless pathogen goes latent)

Question 22

What are the range of relationships between microbes and hosts

Answer 22

Symbiotic (help one another) neutral (form colonies but don’t cause trouble) latent and active infections, disease

Question 23

What is a latent infection?

Answer 23

An infection where the virus is not readily multiplying

Question 24

What is a comunicable disease?

Answer 24

Disease transferred from person to person

Question 25

What is a zoonoses style infection?

Answer 25

Disease transferred from animal to person

Question 26

What is a vector borne disease?

Answer 26

Disease transferred from insect to person

Question 27

What is a nosocomial infection?

Answer 27

Disease transferred from hospital environment to person

Question 28

What is a fomite infection?

Answer 28

Disease transferred from non-living objects to person (toothbrush)

Question 29

What are some routes of infection transmission?

Answer 29

All major orifices in the body, direct injection into blood flow (shot or cut or bite), sexual contact.

Question 30

What are some ways to decrease the duration of infection?

Answer 30

Vaccinate, treat, boost immune system.

Question 31

What are some ways to decrease the number of exposed/susceptible individuals in a population?

Answer 31

Quarantine, vaccinate

Question 32

What does obligate mean?

Answer 32

"must have"

Question 33

What does facultative mean?

Answer 33

"can do either"

Question 34

What does asymptomatic mean?

Answer 34

no symptoms, as noticed by patient

Question 35

What does symptomatic mean?

Answer 35

Symptoms noticeable by patient

Question 36

What does symptomatic mean?

Answer 36

Symptoms noticeable by patient

Question 37

What are the three phylogenetic domains?

Answer 37

Archaea, Bacteria, Eukaryotes

Question 38

Compare and contrast basic features of prokaryotes and eukaryotes. What are some implications of these differences for treatment of disease?

Answer 38

Prokaryotes have smaller ribosomes and peptidoglycans in their cell walls. Both of these traits are not seen in eukaryotes and are targetable differences.

Question 39

Explain the implications for human health and disease of the preponderance and diversity of microbial life on our planet.

Answer 39

There are buckets of things that could go wrong or infect our cells, and there are tons of one-off rare cases because of the sheer number of microbes present on earth. It makes treatment quite tricky.

Question 40

List the six types of human pathogens and identify the basic characteristics of each:

Answer 40

Prions (proteins) viruses (not living) bacteria (living, small, cell wall, peptidoglycans, gram positive or negative, small ribosomes) fungi (yeasts are unicellular, molds are multicellular), protozoa (unicellular eukaryotes), helminths (worms)

Question 41

List six steps common to all infectious disease processes

Answer 41

Encounter, Entry, Spread, Multiply, Damage, Outcome

Question 42

Identify at least five common routes of transmission of infections:

Answer 42

``` Sexual contact Fluid transfer Contact with bloodstream Entry through bodily orifices Inhalation Ingestion Cuts/wounds ```

Question 43

Explain the contributions of efficiency of transmission, duration of infectiousness, and number of exposed contacts to the spread of infectious disease

Answer 43

If you have an efficiently transmitted disease, it will not take much to infect someone once contact is made. Duration of infectiousness allows more people to come into contact with the disease. Number of exposed directly correlates with number of infected.

Question 44

Describe the effects of time and place on the epidemiology of infection.

Answer 44

There are certain infections much more common in Cuba than in the United States. There are certain bacteria much more prevalent in the fall season than in winter or spring.

Question 45

List at least four methods for preventing the spread of infection.

Answer 45

Quarantine, Vaccination, Education, Treatment

Question 46

List at least four methods for preventing the spread of infection.

Answer 46

Quarantine, Vaccination, Education, Treatment