Lecture 1, 2, 3, 4 (Chapter 1)

Question 1

List several ways in which microbes affect our lives.

Answer 1

1) Important in maintaining Earths ecological balance. photosynthesis and form the basic food chain. 2) Live in humans and other animals and are needed to maintain good health (needed for digestion and the synthesis of some vitamins). 3) Are used to produce foods (produce fermented foods: cheese, bread, vinegar) and chemicals (ethanol and acetone). 4) Can cause disease. -soil microbes decompose organic waste

Question 2

Explain the importance of observations made by Hooke and van Leeuwenhoek.

Answer 2

Hooke: Cell Theory- 1) All living things are made of cell 2) Person who made 1st observed and named plants’ cells “little box” van Leeuwenhoek: Person who was 1st to observe living cells- “animalcules” which were bacteria

Question 3

The different types of microbes

Answer 3

Prokaryotes: -Bacteria -Archaea Eukaryotes -Fungi (yeasts, molds) -Protozoa -Microscopic algae -Viruses - different microbes that can only be seen with EM, and they are not cellular

Question 4

3 domains of life

Answer 4

archaea, bacteria, eukarya

Question 5

bacteria are enclosed in special cell walls made of _________ and _________ called Peptidoglycan.

Answer 5

carbohydrates and proteins

Question 6

What’s unique about archaea

Answer 6

live in extreme environments, no peptidoglycan

Question 7

Phylogenetics

Answer 7

study of evolutionary relationships based on the rRNA or other gene protein

Question 8

Black death (1348)

Answer 8

killed 30-60% of Europe and was caused by Yersinia pestis bacteria

Question 9

Robert Hooke

Answer 9

-first to build compound microscopes -observed cork cells (1665) -named them cells because of the shape of hollow cell walls in a slice of cork reminded him of the shape of monks’ cells in a monastery -NEVER observed single celled organisms

Question 10

The idea of cells lead to this theory by Schleiden and Schwann in the 1800s

Answer 10

Cell Theory

Question 11

Anton Van Leeuwenhoek (1650-1693)

Answer 11

-FIRST to observe live microbes -first to observe single celled organisms that he called “animalcules” or small animals -discovered and observed the first bacteria, sperm cells, blood cells, etc. -he was an excellent lens grinder and made very simple-powerful magnifying glasses

Question 12

Edwards Jenner (1796)

Answer 12

-Edwards Jenner inoculated a person with cowpox virus, who was then protected from smallpox -vacca = cow

Question 13

Vaccine protection from a disease is called _______

Answer 13

immunity

Question 14

17th and 18th century concepts: three of them

Answer 14

-diseases caused by “poisonous” air (miasmas) -diseases are transmitted by touch (contagions) still in use -spontaneous generation

Question 15

The idea of spontaneous generation

Answer 15

requires a “vital force” (present in air) to form life

Question 16

Experiments SG vs. BG

Answer 16

Question 17

Pasteur’s s-shaped flask prevented what? And proved what?

Answer 17

left the flask open to air, but the s-shape kept the dust carrying the microbes from reaching the flask. His experiment met the requirement for vital force that SG supporters attested to. So, Pasteur ended the long debate of BG vs SG.

Question 18

Louis Pasteur (1822-1895)

Answer 18

• Disproved the theory of spontaneous generation
• Chemist by background
• Initial work on wine fermentation (wine was souring bc of contaminating microbe) and its control (Pasteurization)
• Developed procedures for vaccinations against both bacterial (cholera, anthrax), and viral diseases (rabies)
• Pasteur realized that souring of wine and infectious disease shared a common thread– in that they both might involve infection by a microorganism. His suggestion that microbes cause disease became known as the germ theory of disease.
• he solved the mysteries of rabies, anthrax, chicken cholera, and silkworm diseases, and contributed to the development of the first vaccines.
• saved a boy who had rabies in 1885. first time.

Question 19

Attenuated vaccine

Answer 19

strain that loses its virulence if it is grown in the lab for long periods of time, we call this “attenuated” when strains of bacteria or viruses have lost thier ability to cause serious disease in the host

Question 20

Robert Koch (1843-1910)

Answer 20

• provided definitive proof of the Germ theory of disease - specific organism cuases a specific disease
• proved this with Koch’s Postulates
• Isolated pure cultures of:

Bacillus anthracis (anthrax)

Neisseria gonorrhoeae (gonorrhea)

Mycobacterium tuberculosis (TB)

Clostridum tetani (tetanus)

Yersinia pestis (plague)

Question 21

Koch’s Postulates

Answer 21

Question 22

Exceptions to Koch’s Postulates

Answer 22

Question 23

Richard Petri

Answer 23

• another of Koch’s assistants
• developed dish that allows gas exchange but prevents microbial contamination
• Petri dish

Question 24

Fannie Eilshemius (Hesse)

Answer 24

• wife of one of Koch’s assistants
• suggested agar could replace potatoes for isolating individual bacterial colonies from mixtures
• agar used as a solidifying agent, providing a level inert surface material for microbes to grow on, other nutrients could be included to satisfy the microbes nutritional needs
• agar is a complex polysaccharide polymer derived from marine algae. Agar is not broken down by bacteria.
• agar is not a food source, it simply solidifies the nutrient medium

Question 25

The last technical achievement in Koch’s lab

Answer 25

formulation of differnt culture media

-a culture medium is a solid or liquid preparation used to grow, transport, and store microorganisms