Exam 1

Question 1

Ergotism

Answer 1

Cause: mold Claviceps purpurea - produces toxic alkaloids
Symptoms: spasms, itching, mania, psychosis
Proposed explanation for bewitchment

Question 2

Van Helmont

Answer 2

recognized that fermentation gave rise to gas and alchohol

Question 3

Van Leeuwenhoek

Answer 3

invented simple microscope

Question 4

Kirchner

Answer 4

Monk

first to claim to see “invisible worms” with microscope

Question 5

Pasteur

Answer 5

researched heat preservation methods
described microbio of lactic acid fermentation
coined aerobic and anaerobic by investigation alch production of yeast
ended debate on spontaneous generation (via swan neck flask exp.)
used attenuated (less virulent) strain as vaccine for chicken cholera
injected Joseph Meister with “aged” spinal cord containing rabies virus

Question 6

Koch

Answer 6

• worked with anthrax, wrote paper pointing to a bacterium as the cause of this disease = validation of germ theory of disease (some diseases are caused by microorgs)
• pure culture studies made possible (potato slices)
• discovered cause of TB and cholera
• Koch’s postulates

Question 7

Koch’s postulates

Answer 7

1. microorg must be found in abundance in all orgs with disease and not in healthy orgs
2. microorg must be isolated from diseased org and grown in pure culture
3. culture should cause disease when put into healthy org
4. microorg must be reisolated from infected person and identified as identical to original

Question 8

Walter Hesse

Answer 8

Koch’s associate
First to use agar to isolate pure culture
Actually was his wife who suggested agar

Question 9

Lister

Answer 9

Observed that people survived surgery but died of “ward fever”
Proposed that microbes in air and on doc’s hand caused post-op infections
introduced thorough cleaning of wound then covering with phenol-saturated cloth
Machine that pumped mist of phenol was used during operations
lactic acid fermentation (showed that a specific bacterium caused the lactic acid fermentation in milk)

Question 10

Ehrlich

Answer 10

Proposes that antibodies contribute to immunity

Shows that they are produced against the plant toxins ricin and abrin

Question 11

Metchnikoff

Answer 11

discovered macrophages

work with phagocytosis

Question 12

Twort

Answer 12

discovered bacteriophage (viruses that affect bacteria) accidentally when he noticed that some bacteria on plates became transparent

Question 13

Transduction

Answer 13

When a bacteriophage inserts a virus into a host, it takes some of the host DNA with it which then is inserted into the next host

Question 14

Griffith

Answer 14

discovers transformation (genetic alteration via uptake of foreign DNA through cell membrane) in bacteria and est. foundation for molecular genetics
Experiment w/ rats

Question 15

Fleming

Answer 15

Publishes first paper describing penicillin and its effects on gram positive bacteria

Question 16

Howard Florey & Ernest Chain

Answer 16

Produce extract of penicillin, isolated from Fleming’s culture - show that it can cure infections in animals

Question 17

Lederberg & Tatum

Answer 17

Describe conjugation in bacteria

Question 18

Transformation

Answer 18

Genetic alteration via uptake of foreign DNA through cell membrane

Question 19

Conjugation

Answer 19

Transfer of genetic material (plasmid) between cells by direct cell to cell contact

Question 20

Crick, Wilkins & Watson

Answer 20

Double helix structure of DNA based on x-ray crystallography done by Rosalind Franklin

Question 21

Rosalind Franklin

Answer 21

Did x-ray cyrstallography of DNA that lead to the description of the double helix structure by Crick, Wilkins and Watson

Question 22

Gilbert & Sanger

Answer 22

Develop methods to sequence DNA

Question 23

Prusiner

Answer 23

Finds evidence that class of infections proteins called prions cause scrapie

Question 24

Prions

Answer 24

Protein molecules
Not infection, conversion: find prion like orgs in host and convert them to the bad form
Infectious agent composed of protein in a misfolded form

Question 25

Mullis

Answer 25

Uses the heat stable enzyme from Thermus aquaticus to establish PCR technology

Question 26

PCR

Answer 26

Polymerase chain reaction

Amplifies a piece of DNA

Question 27

Acetic acid

Answer 27

pKa 4.75
inhibits gram positive and negative
yeasts and molds tolerant
Jellies

Question 28

benzoic acid

Answer 28

pKa 4.19
pH range 2.5-4.5
inhibits yeasts and molds and enzymes
first antimicrobial premitted in foods
jellies

Question 29

parabens

Answer 29

esterification of benzoic acid
pH 3-8
active against yeasts and molds, some bacteria (g+)
targets cytoplasmic membrane
jams

Question 30

sorbic acid/sorbates

Answer 30

pKa 4.75
inhibits yeasts, molds, some bacteria
prevents germination of spores of clostridium botulinum
Jam

Question 31

sodium (NaNO2) and potassium nitrites

Answer 31

curing agents in meats
effective at reduced pH and anaerobic conditions
purpose to inhibit c. botulinum, etc, prevents spore growth
antioxidant
influences flavor, color, lipid oxidation
impacts iron-sulfur clusters (ferredoxins) = reduced ATP production
in acidic environment makes nitrous acid which can make nitric oxide - color fixation in meats
lactic acid bacteria are tolerant
can react with amines to form nitrosamines at high temps = carcinogenic
can oxidize iron to Fe3+ form which cannot bind oxygen (infants)

Question 32

sulfites

Answer 32

ancient Romans and Greeks
effective below pH 4
inhibit DNA replication, enzymes, protein synthesis, damage to cytoplasmic membrane
control spoilage in fruits
some humans are sensitive to it