Chapter 1

Question 1

What did Leeuwenhoek’s discover, and what impact did his skills and his discovery have on science?

Answer 1

• Leeuwenhoek discovered microorganisims
• He was a very skilled observed and made magnifying glasses
• His discovery forever changed the scientific world and Leeuwenhoek was elected to the royal society because of it.

Question 2

What 6 groups of organisms are studied in microbiology?

Answer 2

• bacteria
• viruses
• protozoans
• fungi
• algae
• helminths

Question 3

What are the basic differences between prokaryotic and eukaryotic cells?

Answer 3

• Prokaryotic cells lack nuclei
• Prokaryotic cells are smaller
• Prokaryotic cells have no cytoskeleton

Question 4

What is spontaneous generation?

Answer 4

the supposed production of living organisms from nonliving matter

Question 5

What expirements supported spontaneous generation?

Answer 5

• Needham’s Experiments
• Leeuwenhoek’s discovery of microbes

Question 6

What expirements did not support spontaneous generation?

Answer 6

• Spallanzani’s Experiments
• Pasteur’s Experiments

Question 7

Describe the scientific method

Answer 7

The method by which questions are answered through observations of the outcomes of carefully controlled experiments, instead of by conjecture or according to the opinions of any authority figure.

Question 8

What steps are involved with the scientific method?

Answer 8

Question 9

What did Louis Pasteur discover and what where his contributions to microbiology?

Answer 9

• Pasteur discovers the chemical process behind fermentation
• Pasteur then develops a method to reduce theamount of wine that spoils due to contamination.
• Pasteur also created the pasteurization process

Question 10

What did Robert Koch discover?

Answer 10

Robert Koch discovers the pathogen that causes anthrax, Bacillus anthracis.

Question 11

What are the steps of Koch’s postulates?

Answer 11

1. The suspected agent must be found in every case of the disease and absent from healthy hosts.
2. The agent must be isolated and grown outside the host.
3. Must cause the same disease when introduced to a healthy experimental host.
4. Must reisolate the same agent in the diseased experimental host.

Question 12

What are Microorganisms/microbes?

Answer 12

All organisms that are too small to be seen without a microscope

Question 13

What is a Theory?

Answer 13

a supposition or a system of ideas intended to explain something

Question 14

What is fermentation?

Answer 14

The chemical breakdown of a substance by bacteria, yeasts, or other microorganisms

ex: sugar to alcohol

Question 15

What is metabolism?

Answer 15

the sum of all chemical reactions within an organism

Question 16

What is the germ theory of disease?

Answer 16

Microorganisms are responsible for diseases

Question 17

What is a pathogen?

Answer 17

microorganisms that cause specific disease

Question 18

What is a gram stain?

Answer 18

A stain used to identify bacteria

Question 19

What is recombinant DNA technology?

Answer 19

The manipulationg of genes in microbes, plants, and animals for practical applications

Question 20

What is gene therapy?

Answer 20

A process that involves inserting a missing gene or repairing a defective one in human cells

Question 21

What is meant by gram-positive?

Answer 21

This means that the bacterial cell walls have a relatively thick layer of peptidoglycan that also contains unique chemicals calledteichoic acids.

Question 22

What is meant by gram-negative?

Answer 22

This means that the cell walls have only a thin layer of peptidoglycan, but outside this layer is an asymmetric bilayer membrane.

Question 23

What are the contrubiton of Ignaz Semmelweiss?

Answer 23

Hungarian obstetrician

Pushed aseptic technique specifically hand washing.

Question 24

What are the contrubiton of Joseph Lister?

Answer 24

Used aseptic techniques and cleanliness to decrase mortality

Lister as a surgeon used carbolic acid, or phenol, in the operating room

Question 25

What are the contrubiton of Florence Nightingale?

Answer 25

Used aseptic techniques and cleanliness to decrease mortality rates. Worked as a English nurse in Crimean War kept clean wards, and removed potential tiems of infection. Statistically showed poor food and unclean condition caused deaths

Question 26

What are the contrubition of John Snow?

Answer 26

1854 – mapped an outbreak of cholera in London and showed that it centered around a public water supply. The advent of epidemiology – the occurrence , distribution and spread of disease in humans. Snow highlighted the need for adequate sewage treatment and a clean water supply

Question 27

What are the contrubition of Edward Jenner?

Answer 27

English Physician developed the first vaccine for smallpox from cowpox. Begins the field of immunology

Question 28

What are the contrubition of Paul Ehrlich?

Answer 28

Begins the search for chemicals that destroy pathogen while harmless to humans Alexander Fleming is the first to discover penicilin Leads to chemotherapy

Question 29

Why aren’t Koch’s postulates always useful in proving the cause of a given disease?

Answer 29

Koch’s postulates are not useful in determining the cause of diseases that are not infections. Some diseases only occur under specific conditions, so the microbes may be present in asymptomatic persons, and Koch’s first postulate is not met.

Question 30

Albert Kluyver said “From elephant to…bacterium – it is all the same!” What did he mean?

Answer 30

Kluyver was referring to the metabolism/biochemistry that is common to all cellular life on the planet regardless of the number of cells per organism or size. The statement can be extended to shared cellular structures as well.

Question 31

Algae do not cause disease to humans because?

Answer 31

Algae have simple nutritional requirements (carbon dioxide, water, light, a few salts), which are easily obtained from the environment; therefore, they do not need to obtain nutrients from other living things.

Question 32

How might the debate over spontaneous generation have been different if Buchner had conducted his experiments in 1857 instead of 1897.

Answer 32

Buchner’s experiments demonstrated that intact living cells were not required for fermentation of sugars. Had the experiments been done in the 1850’s, prior to Pasteur’s experiments on spontaneous generation, one argument for spontaneous generation (the appearance of yeast cells in fermenting sugar solutions) would have been weakened. Spallanzani’s results might have been more widely accepted as demonstrating that spontaneous generation does not occur. When scientists accepted that animals do not arise from spontaneous generation, they might have been less likely to exempt microorganisms. ## Footnote

Question 33

The ability of farmers around the world to produce crops such as corn, wheat, and rice is often limited by the lack of nitrogen-based fertilizer. How might scientists use Beijerinck’s discovery to increase world supplies of grain?

Answer 33

Beijerinck’s discovery that some bacteria can convert nitrogen gas to nitrogen compounds is important to the cultivation of these grains. It may be possible to (1) introduce into the soil bacteria capable of converting N2 to organic forms of nitrogen, (2) create soil conditions which promote the growth of such bacteria, and/or (3) genetically modify crop plants with bacterial genes to convert nitrogen gas for themselves.