Intro. to Microbiology (BE #1)

Question 1

Define microbiology

Answer 1

study of microorganisms

Question 2

Define microorganisms

Answer 2

organisms invisible to the naked eye

Question 3

Differentiate between prokaryotic & eukaryotic cells. Give examples of each.

Answer 3

1. Prokaryotic - “before nucleus” - cells with no internal membrane-bound structures. Includes only bacteria
2. Eukaryotic - “after nucleus” - have internal membrane-bound structures; includes organisms such as protistans, fungi, animals (including helminths), and plants.

Question 4

Name 6 groups of pathogens we will study. ID if they are cellular or acellular

Answer 4

1. Bacteria - cellular
2. Viruses - acellular
3. Prions - acellular
4. Protistans - cellular
5. Fungi - cellular
6. Helminths - cellular

Question 5

Name the two major groups of bacteria.

Answer 5

1. Eubacteria

2. Archaebacteria (no known pathogens)

Question 6

Which group includes pathogenic (disease causing) bacteria?

Answer 6

Eubacteria

Question 7

What are the 4 basic shapes of bacteria?

Answer 7

1. bacillus/bacilli - rod
2. coccus / cocci - spherical
3. spirillum / spirilli - spiral
4. vibrio - curved rod

Question 8

Give an example of a disease caused by bacteria.

Answer 8

strep throat

Question 9

Describe organisms belonging to Protista.

Answer 9

Single-celled, eukaryotic; some are animal-like, some are plant-like

Question 10

Give an example of a disease caused by a protistan.

Answer 10

malaria 
giardiasis ("don't drink the water")

Question 11

Name the 2 types of fungi. Which one is unicellular & which one is multicellular?

Answer 11

1. yeasts - unicellular

2. molds - multicellular

Question 12

Give an example of a disease caused by a fungus.

Answer 12

vaginal yeast infection
diaper rash
athlete's foot
thrush
ringworm
jock itch
dandruff

Question 13

What is the basic structure of a virus?

Answer 13

a piece of nucleic acid (RNA or DNA) enclosed by a protein coat (capsid)

Question 14

Give an example of a disease caused by a virus.

Answer 14

1. warts
2. cold
3. Hepatitis A
4. chicken pox
5. measles
6. mumps
7. flu

Question 15

What is the structure of a prion?

How does is cause disease?

Answer 15

mutated protein

by mutating other proteins

Question 16

Give an example of a disease caused by a prion.

Answer 16

Mad cow disease
Scrapie
Creutzfeld-Jakob Disease

Question 17

Father of chemotherapy

Answer 17

Ehrlich

Question 18

1. One of the Fathers of microbiology
2. Described the first microorganism (it was a fungus)
3. First described “cellular” in cork; discovery led to the formulation of the cell theory.

Answer 18

Hooke

Question 19

Discovered first antibiotic (penicillin)

Answer 19

Fleming

Question 20

1. Developed the germ theory of disease (microbes cause disease & specific microbes cause specific diseases) AND
2. Developed the agar plate method for culturing microbes.

Answer 20

Koch

Question 21

Developed the first vaccination by inoculating people with cowpox to produce immunity against small pox.

Answer 21

Jenner

Question 22

1. Used a curved neck flask to finally disprove the theory of spontaneous generation.
2. Developed anthrax & rabies vaccines

Answer 22

Pasteur

Question 23

Poured boiled chicken broth into a flask; microbes grew; concluded that spontaneous generation does occur (flask was not sterile)

Answer 23

Needham

Question 24

11. Disproved the theory of spontaneous generation for macroscopic organisms (fly maggots and meat experiment).

Answer 24

Redi

Question 25

One of the fathers of microbiology;

Described the first bacteria

Answer 25

Leeuwenhoeck

Question 26

Put broth in a flask, sealed it, and boiled it; thought he had disproved spontaneous generation, but critiques said he had just proved that the process required air.

Answer 26

Spallanzani

Question 27

15. Discovered that childbed fever was due to doctors not washing their hands after performing autopsies.

Answer 27

Semmelweis

Question 28

16. First to develop antisepsis; treated wounds with bandages soaked in carbolic acid.

Answer 28

Lister

Question 29

17. Suggested that Koch try using agar to thicken culture media

Answer 29

Frau Hesse

Question 30

Explain the theory of spontaneous generation.

Answer 30

theory that living organisms can develop from non-living organisms

Question 31

Explain how Jenner discovered the first official vaccine for smallpox.

Answer 31

He observed that cow maids who had cowpox (blisters) seemed immune to smallpox. He inoculated a boy with fluid from a cowpox blister & he came down with it. He then injected him with fluid from a smallpox blister & he didn’t get it.

Question 32

ID the 4 postulates of the germ theory of disease (Koch’s).

Answer 32

1. The causative agent must be present in every individual with the disease;
2. The causative agent must be isolated and grown in pure culture in a lab;
3. The pure culture must cause disease when inoculated in a healthy animal;
4. The causative agent must be reisolated from the animal & reidentified in pure culture.

Question 33

Why was agar more successful than gelatin as an additive to thicken culture media?

Answer 33

Agar has a higher melting point.

Question 34

Explain how Fleming accidentally discovered penicillin

Answer 34

Fleming had inoculated plates with the bacteria Staphylococcus aureus. On returning, Fleming noticed that one culture was contaminated with a fungus. Instead of tossing the plate in the trash, he took a closer look at the plate. The colonies of Staphylococcus that had immediately surrounded the fungus had been destroyed, whereas other colonies further away were normal. He set out to discover what antibacterial compound the fungus was producing.

Question 35

Explain 2 exceptions to the postulates of the germ theory.

Answer 35

1. Some pathogens will not grow on artificial media in the lab (ex. viruses can only survive and multiply within living host cells
2. Some pathogens will not infect lab animals – many pathogens are species specific (they will only infect 1 species of animals); some human pathogens will not infect animals

Question 36

Explain the principle of selective toxicity.

Answer 36

Erlich - The drug should be toxic to the infecting microbe, but relatively harmless to the host.

to do this, target a difference between the pathogen and the host