Topic 1: The Microbial World

Question 1

Contributions made by Robert Hooke

Answer 1

1. first to see a microorganism (fungi)
2. discovered cells
3. compound microscopes
   (didn’t discover bacteria and archaea)

Question 2

Microbiology

Answer 2

Study of organisms too small for the naked eye

Question 3

Contributions made by Antonie Van Leeuwenhoek

Answer 3

1. father of microbiology
2. first to see and describe bacteria
3. made improvements to the microscope (one lens)

Question 4

Basic Requirements for Microbial Life(6)

Answer 4

1. Metabolism
2. Growth
3. Reproduction
4. Genetic variation/evolution
5. Response/adaptation to the external environment
6. Homeostasis (maintaining internal organization and order, usually by expending energy)

Question 5

Macromolecule: Polypeptide

Answer 5

Subunit: Amino Acids
Dry weight of cell %: 50-55

Question 6

Macromolecule: Nucleic Acids

Answer 6

Subunit: DNA, RNA
Dry weight of cell %: DNA 2-5, RNA 15-20

Question 7

Macromolecule: Lipids

Answer 7

Subunit: Diverse structures
Dry weight of cell %: 10

Question 8

Macromolecule: Polysaccharides

Answer 8

Subunit: Sugars
Dry weight of cell %: 6-7

Question 9

Characteristics of the three domains: Nuclear membrane

Answer 9

B: No
A: No
E: Yes

Question 10

Characteristics of the three domains: Membrane-bound organelles

Answer 10

B: rare, a few types found in a few species
A: rare, a few types found in a few species
E: multiple distinct types, found in all species

Question 11

Characteristics of the three domains: Plasma membrane

Answer 11

B: similar to eukarya
A: different form B + E
E: Similar to bacteria

Question 12

Characteristics of the three domains: Cell wall

Answer 12

B: found in nearly all species , constructed of peptidoglycan
A: found in nearly all species, constructed of various materials
E: found in some species, constructed of various materials

Question 13

Characteristics of the three domains: RNA polymerase

Answer 13

B: single polymerase
A: single polymerase, eukaryal-like RNA pol II
E: Three main polymerases ( RNA pol I, II, III)

Question 14

Characteristics of the three domains: Histones

Answer 14

B: Histone like proteins
A: yes
E: yes

Question 15

Major events leading to origin of microbial life

Answer 15

• first O2 producing bacteria
• O2 atmosphere
• Endosymbiosis (chloroplasts and mitochondria)
• origin of complex eukarya
• origin of multicellular organisms
• origin of simple animals

*RNA world: hypothesis that RNA came before DNA

Question 16

Cyanobacteria and Endosymbiosis and Earths History

Answer 16

C: first organism to release oxygen gas a waste product by oxidizing water, made world breathable
E: Prokaryotic microbes ingested other microbes starting a symbiotic relationship and forming first basic eukaryotes (mitochondria and chloroplasts came from this)

Question 17

Earliest microbes would have

Answer 17

been able to metabolize iron and/or sulfur
been thermophiles (heat loving)
been anaerobic (producing atp with absence of oxygen)
been able to use light energy
consumed inorganic carbon (e.g., carbon dioxide)

Question 18

Microbial Metabolism

Answer 18

Microbes obtain the energy and nutrients they need to live and reproduce

Question 19

Autotrophs

Answer 19

primary producers
have ability to fix CO2 into organic molecules
self- feeding

Question 20

Heterotrophs

Answer 20

ingest organic molecules from primary producers
eats other things

Question 21

Photosynthesis

Answer 21

the process by which plants use sunlight, water, and co2 to create oxygen and energy in the form of sugar

Question 22

Cellular respiration

Answer 22

metabolic pathway that uses glucose to produce ATP

Question 23

Fermentation

Answer 23

uses organic matter as both electron donor and acceptor

Question 24

Aerobic respiration

Answer 24

uses organic matter as the electron donor, but it uses oxygen as a much more powerful electron acceptor

Question 25

Anaerobic respiration

Answer 25

doesnt use oxygen, can use carbon, nitrogen, sulfate, iron, manganese

Question 26

Louis Pasteur

Answer 26

1. discovered that living organisms discriminate between optical isomers
2. discovered the biological nature of alcoholic fermentation
3. developed vaccines for anthrax, fowl cholera, and rabies
4. disproved spontaneous generation and developed methods for controlling growth of microorganisms
5. developed pasteurization
6. developed sanitization in hospitals

Question 27

Kochs postulate

Answer 27

1. suspected microbe is identified in people with a disease, not in those without illness
2. a pure culture of the suspected microbe is obtained
3. experimental inoculation of the suspected microbe into a healthy test host causes the same illness
4. the suspected microbe is recovered from the experimentally inoculated host organism and has to be same as original

Question 28

Impact of microorganisms on human health

Answer 28

Diseases,
- stomach ulcers (bacteria Helicobacter pylori)
- bubonic plague (bacteria Yersinia pestis)
- small pox (smallpox virus)
- influenza (virus)

Infections
Viruses