Lecture 1, 2, 3, 4 (Chapter 1) Flashcards
List several ways in which microbes affect our lives.
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
Explain the importance of observations made by Hooke and van Leeuwenhoek.
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
The different types of microbes
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
3 domains of life
archaea, bacteria, eukarya
bacteria are enclosed in special cell walls made of _________ and _________ called Peptidoglycan.
carbohydrates and proteins
What’s unique about archaea
live in extreme environments, no peptidoglycan
Phylogenetics
study of evolutionary relationships based on the rRNA or other gene protein
Black death (1348)
killed 30-60% of Europe and was caused by Yersinia pestis bacteria
Robert Hooke
-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
The idea of cells lead to this theory by Schleiden and Schwann in the 1800s
Cell Theory
Anton Van Leeuwenhoek (1650-1693)
-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
Edwards Jenner (1796)
-Edwards Jenner inoculated a person with cowpox virus, who was then protected from smallpox -vacca = cow
Vaccine protection from a disease is called _______
immunity
17th and 18th century concepts: three of them
-diseases caused by “poisonous” air (miasmas) -diseases are transmitted by touch (contagions) still in use -spontaneous generation
The idea of spontaneous generation
requires a “vital force” (present in air) to form life
Experiments SG vs. BG
Pasteur’s s-shaped flask prevented what? And proved what?
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.
Louis Pasteur (1822-1895)
- 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.
Attenuated vaccine
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
Robert Koch (1843-1910)
- 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)
Koch’s Postulates
Exceptions to Koch’s Postulates
Richard Petri
- another of Koch’s assistants
- developed dish that allows gas exchange but prevents microbial contamination
- Petri dish
Fannie Eilshemius (Hesse)
- 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
The last technical achievement in Koch’s lab
formulation of differnt culture media
-a culture medium is a solid or liquid preparation used to grow, transport, and store microorganisms
