M7: Koch and Pasteur

Question 1

what is the miasma theory?

Answer 1

The theory that bad air from rotting food causes disease

Question 2

what is the theory of spontaneous generation?

Answer 2

hypothetical process by which living organisms develop from non-living matter

Question 3

experiment example for a spontaneous generation?

Answer 3

1600’s Francesco experiment - rotting meat in a jar

Question 4

who is Louis Pasteur?

Answer 4

man who found that microorganisms were responsible for spoiling liquids. He then discovered the process of pasteurisation > heating of liquids to kill pre-existing microbes.

Question 5

what theories did Pasteur prove and disprove?

Answer 5

• proved the germ theory
• disproved spontaneous generation

Question 6

what was Pasteur’s famous experiment?

Answer 6

Swan necked flask experiment
- boiled broths in flasks to kill pre-existing bacteria
- broke one neck and left the other

Question 7

what was the result of the swan-necked flask experiment?

Answer 7

• the neck that was broken was contaminated by microbes while the one intact had no microbes
• therefore if broken then contaminated

Question 8

how does the swan-necked flask experiment work?

Answer 8

• the S shape when unbroken has condensing water that collects sealing the mouth
• gravity pulls heavier particles, like dust and microbes, down to settle in the bends of the neck rather than continuing through to the broth.

Question 9

what did Robert Koch do?

Answer 9

• established a relationship between microbial pathogens and disease
• built on germ theory and paved the way for vaccines

Question 10

how did Koch prove the germ theory

Answer 10

• Koch’s postulates
• extracting bacterium from diseased animals, growing it, and reinjecting into healthy organisms to see if the same disease reoccured (it did)

Question 11

how many postulates are there?

Answer 11

4

Question 12

what is postulate 1?

Answer 12

the microorganism must be found in diseased but not healthy individuals

Question 13

what is postulate 2?

Answer 13

the microorganism must be cultivated in pure culture away from the infected body

Question 14

what is postulate 3?

Answer 14

Inoculation of a healthy individual with the cultured microorganism must recapitulate the disease

Question 15

what is postulate 4?

Answer 15

the microorganism should be re-isolated from the experimentally infected organisms and recultured. It should be the same microbes.

Question 16

what are the three theories of disease?

Answer 16

• miasma theory
• germ theory
• theory of spontaneous generation

Question 17

What are the names of the two most helpful scientists who have proven and disproved theories of disease?

Answer 17

• Robert Koch
• Louis Pasteur