ch. 1 - microbiology history

Question 1

what are the 7 major groups studied by microbiologists?

Answer 1

viruses, protozoa, bacteria, archaea, prions, helminths, fungi

Question 2

what is microbiology?

Answer 2

the study of microscopic life - organisms, including bacteria, archaea, fungi, protozoa, helminths, etc.

Question 3

what are microscopic organisms?

Answer 3

living things that are too small to be seen without magnification

Question 4

what types of microbes do not appear on the tree of life?

Answer 4

viruses and prions

Question 5

how were microbes first detected?

Answer 5

through sickness

Question 6

are microorganisms harmful?

Answer 6

vast majority of microorganisms that associate with humans are harmless or beneficial

Question 7

what are pathogens?

Answer 7

microbes that cause disease
- over 2,000 kinds
- ten billion infections occur across the world/evry year
- infectious disease = among most common cause of deaths

Question 8

what is a microscope?

Answer 8

an upside down telescope

Question 9

who created the compound microscope?

Answer 9

Robert Hooke - in 1625
- magnify 25x

Question 10

who was Anton von Leeuwenhoek? and what did he create?

Answer 10

• had skills in grinding lenses
• samples magnified 200-300x
• had described “animalcules”

Question 11

what is the vital force?

Answer 11

the idea that life came from dead or decaying materials

Question 12

what is biogenesis?

Answer 12

the idea that life comes from life

Question 13

how do you disprove something?

Answer 13

• create an experiment

Question 14

what was the experimentation for the biogenesis theory?

Answer 14

observation: maggots appear from rotting meat

• leeuwenhoek suggested maggots arose from eggs in the decaying material, not the material itself

francesco redi designed an experiment and found if flies were prevented from landing on the meat, it did not produce maggots

Question 15

what happened in Pasteur’s first experiment?

Answer 15

• he started with sterile liquid (broth)
• the flask is open
• over time, things fall in, microorganisms fall in and begin to grow

Question 16

what happened in Pasteur’s second experiment?

Answer 16

• he started with sterile liquid (broth)
• the flask is sealed
• no microorganisms

Question 17

what happened in Pasteur’s third experiment?

Answer 17

• started with sterile liquid (broth) in a swan-neck flask
• flask upright: no organisms grow
• break swan-neck: organisms grow
• tilt then stand upright: microbes reach the broth and grow

Question 18

what is epidemiology?

Answer 18

the study of cause and transmission of disease
- first study done by Ignaz Semmelweis
–> many pregnant women were dying of blood poisoning in the hospital
29% death by med student
3% death by midwifery student
—> turns out med students handled cadavers (w/o gloves) right before
—> Semmelweis suggested handwashing, rejected by most physicians

Question 19

how did Ignaz Semmelweis’ idea of handwashing lower the death rate of birthing women?

Answer 19

• he noticed the transmission of disease (from the cadavers to the birthing women)
• he then instructed students to wash their hands = death rate lowering

Question 20

who was john snow and what was his contribution in epidemiology?

Answer 20

• found a connection of cholera outbreaks between sewer pumps and the supply of drinking water
• his work created modern sanitation standards

Question 21

what is florence nightingale known for?

Answer 21

she laid foundation for modern sanitary practices
- separate linens + towels for each patient
- cleaning of floors
- unclogging of sewage pipes

Question 22

what does bacteria mean in latin?

Answer 22

= little rods

• christian ehrenberg called them this

Question 23

what is germ theory and who proposed it?

Answer 23

• that certain animalcules/bacteria could cause human disease
• Louis Pasteur

Question 24

how did pasteurization come to be?

Answer 24

Louis Pasteur heated liquids to 55 degrees celcius to keep bacteria from growing

(cheese and wine)

Question 25

how was antisepsis created?

Answer 25

Joesph Lister used carbolic acid spray on wounds after surgery - got the idea from john snow and the cholera outbreak in the sewers - Lister also made listerine

Question 26

what was the unethical experiment that Robert Koch did with his cattle and the sheperd's?

Answer 26

- Robert Koch, Father of Microbiology, connected bacteria to disease - demonstrated that single organisms could cause disease - he hired shepherds to care for diseased sheep, leaving them unaware to the sickness (anthrax), the shepherd's would get sick and die, like the sheep would

Question 27

what are Koch's rules (4)?

Answer 27

1) the disease has to be present in every case of the disease 2) microorganisms are isolated from the tissues of a dead animal, and a pure culture is prepared 3) microorganism from pure culture are inoculated into a healthy susceptible animal, if it becomes diseased = reproduced 4) identical microorganisms are isolated and recultivated from the tissue specimens of the experimental animal

Question 28

what did the Chinese do with smallpox scabs as a treatment? (variolation)

Answer 28

- they would grind up smallpox blisters and snort it up the nose - often times it worked

Question 29

What connection did Edward Jenner make between his milkmaids and the cows with cowpox on their utters?

Answer 29

- he concluded that since the milkmaids had cowpox lesion on their hands like the cows did on their utters, they were resistant to it - he used cowpox lesions to inoculate people (his children included), would put cowpox lesion in a cut -created vaccinations (vacca=cow)

Question 30

what did Dimitri Ivanowsky discover with his tobacco plants?

Answer 30

- used Koch's postulates to figure out that an organism was causing tobacco mosaic disease on his plants, even after filtering the liquid - concluded it was a contagious, living poison liquid (=virus)

Question 31

what did Walter Reed discover that gave birth to the study of virology?

Answer 31

- he was the first to identify yellow fever (lots of hepatitis) was caused by a virus, not the liquid - was able to see the virus using electron microscope - viruses are 100x smaller than bacteria

Question 32

how did Alexander Fleming discover penicillin?

Answer 32

- he had left a BLT growing mold in this lab, the mold "Penicillin" was keeping the bacteria he was working with away - was available for mass consumption by 1940s - antibiotic resistance started by not taking ALL of the antibiotics - people are now dying of strep throat bc of it

Question 33

how has the human microbiome helped new research?

Answer 33

- the microbes in our gut affect our personality (depression and anxiety could be treated with antibiotics) - menstruation cravings are due to the bacteria secreting substances craving sweet, salty and fat substances - gut microbes release neurotransmitters

Question 34

where are microbes in our planet?

Answer 34

- microbes produce CO2, NO, and CH3 - insulating the earth's atmosphere - microorganisms are the most abundant cellular organisms in the oceans - viruses - most abundant inhabitants of the oceans - bacteria + fungi live in close association with plants and assist them in obtaining nutrients + water and may protect them against disease

Question 35

what are prokaryotes?

Answer 35

- no nucleus - no organelles - all microbes - older, 4 billion years old - simple, small *** bacteria + archae *** - 10x more mass than eukaryotes - all are microorganisms and unicellular

Question 36

what are eukaryotes?

Answer 36

- has a nucleus - has organelles - some are microbes - single celled - multi-celled - complex, big - newer, 2 billion years old *** all other life on earth*** - only some are microorganisms; others can be seen with the naked eye ex.) animals, plants, fungi, protozoa

Question 37

what are organelles?

Answer 37

small, double-membrane bound structures that perform specific functions in a cell - including nucleus, mitochondria, chloroplasts

Question 38

what are the three rules for writing nomenclature?

Answer 38

1) genus names start w/ a capital letter 2) species - lowercase letter 3a) underline both - written by hand 3b) italicize both - when typed - abbreviations -> genus name abbreviated followed by a period, then full species name

Question 39

what is unique about viruses?

Answer 39

- they are not independently living cellular organisms ( don't make ATP) - composed of hereditary material (DNA OR RNA, not both) + a protein coat - inside host organism, they exist as a form of genetic material that confers a partial genetic program on the host

Question 40

what are the descending ranks used, from general all-inclusive taxonomic to smallest and most specific category ?

Answer 40

- domain - kingdom - phylum or division - class - order - family - genus -species