Introduction and History of Microbiology

Question 1

What is the most populous and diverse group of organisms?

Answer 1

Microorganisms.

Question 2

Where are microorganisms found?

Answer 2

Everywhere.

Question 3

How do microorganisms benefit the world around them?

Answer 3

1. Recycling essential elements.
2. Source of nutrients.
3. Carry out photosynthesis.
4. Help produce food, beverages, vitamins, and antibiotics.

Question 4

Are all microorganisms beneficial?

Answer 4

No, some cause disease.

Question 5

What are the 2 main types of microorganisms?

Answer 5

1. Cellular.
2. Acellular.

Question 6

What sub-types of microorganisms fall under cellular?

Answer 6

1. Fungi.
2. Protists.
3. Bacteria.
4. Archaea.

Question 7

What sub-types of microorganisms fall under acellular?

Answer 7

1. Viruses.
2. Viroids.
3. Satellites.
4. Prions.

Question 8

What are the two types of microbial cells?

Answer 8

1. Prokaryotic cells.
2. Eukaryotic cells.

Question 9

What are prokaryotic cells (in simple)?

Answer 9

Cells that lack a true membrane-defined nucleus.

Question 10

What are eukaryotic cells (in simple)?

Answer 10

Cells that have a membrane-bound nucleus, more complex morphology, and are usually larger than prokaryotic cells.

Question 11

What is the 3 domain system based on?

Answer 11

Ribosomal RNA genes.

Question 12

What are the 3 domains?

Answer 12

1. Bacteria (true bacteria).
2. Eukarya (eukaryotes).
3. Archaea.

Question 13

What is the total size of the eukaryotic ribosome?

Answer 13

80s.

Question 14

What is the size of the large eukaryotic ribosomal subunit and how many proteins does it contain?

Answer 14

1. 60s.
2. 50 proteins.

Question 15

What is the size of the small eukaryotic ribosomal subunit and how many proteins does it contain?

Answer 15

1. 40s.
2. 33 proteins.

Question 16

What is the total size of the prokaryotic ribosome?

Answer 16

70s.

Question 17

What is the size of the large prokaryotic ribosomal subunit and how many proteins does it contain?

Answer 17

1. 50s.
2. 34 proteins.

Question 18

What is the size of the small prokaryotic ribosomal subunit and how many proteins does it contain?

Answer 18

1. 30s.
2. 21 proteins.

Question 19

What does knowing the proteins for ribosomal subunits allow for?

Answer 19

Classifying microorganisms at the genus or species level.

Question 20

What are the characteristics of Domain Bacteria?

Answer 20

1. Usually single-celled.
2. Most lack a membrane-bound nucleus.
3. Majority have a peptidoglycan cell wall.
4. Ubiquitous, but some live in extreme environments.

Question 21

What are the characteristics of Domain Archaea?

Answer 21

1. Distinguished from bacteria by a unique RNA sequence.
2. Lack a peptidoglycan cell wall.
3. Some have unusual metabolic characteristics.
4. Have unique lipid membranes.
5. Many live in extreme environments.

Question 22

What are the 2 major divisions of Domain Eukarya?

Answer 22

1. Protists.
2. Fungi.

Question 23

What are the major characteristics of Domain Eukarya-Protists?

Answer 23

1. Generally larger than bacteria and archaea.
2. Algae: Photosynthesis.
3. Slime molds: Two-stage life cycle.
4. Water molds: devastating disease in plants.
5. Protozoa: May be motile “hunters, gatherers”.

Question 24

What are the major characteristics of Domain Eukarya-Fungi?

Answer 24

1. Yeast: Unicellular.
2. Mold: Multicellular.

Question 25

What are the acellular infectious agents?

Answer 25

1. Viruses. 2. Satellites. 3. Viroids. 4. Prions.

Question 26

What are the characteristics of viruses?

Answer 26

1. Smallest of all microbes. 2. Require host cells to replicate. 3. Causes a range of diseases and some cancers.

Question 27

What is the characteristic of a satellite?

Answer 27

Comprised of a protein coat and nucleic acid.

Question 28

What is the characteristic of a viroid?

Answer 28

An infectious agent composed of RNA.

Question 29

What is the characteristic of a prion?

Answer 29

An infectious protein.

Question 30

Who built the first microscope, thereby discovering microorganisms?

Answer 30

Antony/ie von Leeuwenhoek. *First to describe them ACCURATELY.

Question 31

What is the idea of spontaneous generation?

Answer 31

The idea that living organisms can develop from decomposing or non-living matter.

Question 32

Who disproved spontaneous generation and how?

Answer 32

Francesco Redi disproved it by putting out 2 pieces of meat. He covered one and left the other uncovered. Maggots developed in the uncovered meat, but not the covered meat.

Question 33

What experiment did John Needham do and why?

Answer 33

He put mutton broth in flasks, boiled it, then sealed it. This was done to prove spontaneous generation applied to microbes.

Question 34

What was the result and what did Needham do wrong?

Answer 34

There was microbial growth. He did not seal the flask first.

Question 35

What experiment did Lazzaro Spallanzani do?

Answer 35

The same as Needham, he just sealed the flask first.

Question 36

What was the result of Spallanzani's experiment?

Answer 36

No growth of microorganisms.

Question 37

What experiment did Louis Pasteur's conduct?

Answer 37

The swan-neck flask experiment. Two swan-neck flasks containing nutrient solution were exposed to heat, boiling the nutrient solution. Then both flasks were left unsealed.

Question 38

What was the result of Pasteur's first experiment?

Answer 38

No growth of microorganisms.

Question 39

What happened when Pasteur reran the experiment, but snapped the neck off of one of the flasks? What did this rerun prove?

Answer 39

1. The flask with the missing neck became contaminated with microorganisms. 2. It proved that microorganisms were getting stuck in the curve of the neck of the flasks, keeping the broth sterile.

Question 40

What were originally believed to be the causes of disease?

Answer 40

1. Supernatural forces. 2. Imbalances in the 4 bodily humors.

Question 41

What was required to establish a connection between microbes and disease?

Answer 41

The development of techniques for studying microbes.

Question 42

What did the earliest studies to establish a connection between microbes and disease focus on?

Answer 42

Plants and fungi.

Question 43

What 2 methods of work did Joseph Lister develop that provided indirect evidence that microorganisms cause disease?

Answer 43

1. He developed a method for treating surgical dressings and instruments. 2. He developed a surgery system designed to prevent microorganisms from entering wounds.

Question 44

What was the outcome of Lister's methods of work?

Answer 44

His patient's had a much lower incidence of postoperative infection.

Question 45

What bacteria and disease did Robert Koch connect?

Answer 45

Bacillus anthracis and anthrax.

Question 46

What system did Koch develop that is used to connect a particular microorganism to a particular disease?

Answer 46

Koch's Postulates.

Question 47

What is Koch's first postulate?

Answer 47

The microorganism must be present in every case of the disease but absent from heathy organisms.

Question 48

What is Koch's second postulate?

Answer 48

The suspected microorganism must be isolated and grown in pure culture.

Question 49

What is Koch's third postulate?

Answer 49

The same disease must result when the isolated microorganism is inoculated into a healthy host. *The healthy host can be another species than that of the origina host.

Question 50

What is Koch's fourth postulate?

Answer 50

The same microorganism must be isolated again from the diseased host.

Question 51

What did Koch's work lead to the discovery and development of (5 things)?

Answer 51

1. Agar. 2. Nutrient agar. 3. Petri dish. 4. Nutrient broth. 5. Methods for isolating microorganisms.