Lecture 1

Question 1

Robert Hooke

Answer 1

• examined a cork and was able to see individual cells
• discovered “little boxes”
• cell theory: all living things are made of cells
• could see cells, but not bacteria

Question 2

Anton van Leeuwenhoek

Answer 2

• constructed a microscope powerful enough to see microbes for the first time
• called these microbes “animalcules”
• made drawings of these animalcules

Question 3

Define “spontaneous generation.”

Answer 3

The idea that some forms of life arise from non-living matter.

Question 4

Define “biogenesis.”

Answer 4

The hypothesis that living organisms come from pre-existing living things.

Question 5

Louis Pasteur

Answer 5

• defeated the idea of spontaneous generation by doing his heating of the flask experiment
• showed that it was microbes in the air that led to microbe growth, not the air itself
• also contributed to cholera, rabies and anthrax vaccines
• aseptic technique: heat can destroy microbial life
• pasteurization: preservation of milk and other foods to reduce spoilage

Question 6

Link between microbes and diseases

Answer 6

• early beliefs: demons, bad air, punishment for bad behaviour
• modern discoveries: Germ theory

Question 7

Define “Germ Theory”

Answer 7

The principle that microbes cause disease.

Question 8

Joseph Lister

Answer 8

• infections were transmitted from one patient to another by physicians
• washed hands before and after each patient to reduce transmission
• disinfected surgical wounds with phenol
• deaths reduced

Question 9

Robert Koch

Answer 9

• used anthrax bacterium to demonstrate Germ Theory of disease
• noticed bacteria in blood of cows with anthrax
• isolated this bacteria and injected it into healthy cows who eventually became sick
• the same bacteria was present in both groups of cows
• this proved that a specific microbe causes a specific disease (Koch’s postulates)
• applied his postulates to determine the cause of tuberculosis
• methods of growing pure cultures to obtain colonies
• worked with Richard Petri to obtain pure cultures Petri dish
• pure cultures led to the taxonomy and classification of bacteria

Question 10

Edward Jenner

Answer 10

• made the first vaccine
• infected a healthy 8-year-old with cowpox in order to test his theory that those with cowpox could not be infected by smallpox
• patient never contracted cowpox

Question 11

Define “immunity.”

Answer 11

Being resistant to a certain infectious disease or pathogen.

Question 12

Alexander Fleming

Answer 12

• how to treat bacterial diseases without harming the host?
• noticed his bacterial plates were contaminated with fungus
• there was a clear area around the mold were bacterial growth was inhibited
• the fungus (Penicillium chrysogenum) secreted a compound that could kill bacteria

Question 13

Martinus Beijerinck

Answer 13

• first to use enrichment cultures, which are highly selective media and incubation conditions
• isolated first pure cultures from soil and aquatic ecosystems
• first to describe a virus (TMV)

Question 14

Sergi Winogradsky

Answer 14

• isolated diverse metabolic types of bacteria, including chemolithotrophs
• first to demonstrate nitrogen fixation
• liked to study microbes in a community rather than as pure culture (Winogradsky columns)