INTRODUCTION MICROBIOLOGY Flashcards
1
Q
what is microbiology?
A
The study of living organisms of microscopic size including bacteria, fungi, algae, viruses and parasite
2
Q
what are the three levels of cellular organisation in whittaker’s five kingdom concept?
A
Ingestion, photosynthesis and absorption
3
Q
what are the five kingdoms in whittaker’s classification?
A
Monera, Protista, Plantae, Fungi and Animalia
4
Q
What are the similarities between Archaea and eukaryotes?
A
Both have histones (nucleosomes), complex RNA polymerases and use methionine as protein initiator amino acids
4
Q
what differentiates eubacteria from archaea?
A
Eubacteria have peptidoglycan in their cell walls, while archae do not
5
Q
what are the main types of cells ?
A
Prokaryotes and Eukaryotes
6
Q
which domain belong to prokaryotes?
A
Eubacteria and Archaea
7
Q
what distinguishes prokaryotic cells from eukaryotic cells?
A
prokaryotic cells lack a nucleus and membrane bound organelles while eukaryotic cells have both
8
Q
what are the 2 major groups of bacteria in the domain Eubacteria?
A
Heterotrophic bacteria and cyanobacteria
9
Q
what are the key characteristics of archaea?
A
They can survive in extreme environments and include groups like halophiles, thermophiles and methanogen
10
Q
Name 3 major groups within the domain eukaryotes
A
plants fungi and animals
11
Q
who first proposed a version of the germ theory in 1546?
A
Fracastoro
11
Q
what did Robert Hooke observe in 1665?
A
he observed cork cells under a microscope
11
Q
who observed single celled organisms in 1674?
A
Van Leeuwenhoek
12
Q
what did John snow demonstrate in 1854?
A
That cholera was transmitted in contaminated drinking water
13
Q
what did Louis Pasteur discover about fermentation in 1857?
A
that microbial fermentation was responsible for spoilage in beer and wine
14
Q
who demonstrated that handwashing reduces puerperal infections in 1847?
A
semmelweis
15
Q
Louis Pasteur’s discoveries led to the development of germ theory (TRUE/FALSE)
A
True
15
Q
what experiment did Pasteur use to disprove spontaneous generation in 1862?
A
the swan-neck flask experiment
15
Q
what antiseptic techniques did joseph Lister begin using in 1867?
A
Carbolic acid as a disinfectant during surgery
16
Q
who determined that microbes cause many bacteria infections between 1876 and 1906?
A
Robert Koch and his workers
17
Q
Robert Hooke was the first to observe living microorganisms (TRUE/FALSE)
A
FALSE van leeuwenhoek observe living microorganisms
18
Q
John Snow’s findings helped advance modern epidemiology first (TRUE/FALSE)
A
TRUE
19
Q
Who is considered the father of microbiology?
A
Anthony van Leeuwenhoek
20
what was Anthony van Leeuwenhoek's major discovery?
He was the first to observe and describe microorganisms
(animalcules) using single lens microscope
21
what improvement did Anthony van Leeuwenhoek make to microscopy?
he developped lenses with up to 300x magnification
22
what was the significance of Francesco Reddy experiment with maggots?
It disproved spontaneous generation by showing that maggots arise from flies, not spontaneously from meat
23
what was Francesco Redi trying to disprove with his experiment?
The theory of spontaneous generation
24
what was the purpose of Redi first experiment?
To observe if maggots appeared on uncovered meat
25
what happened to the meat in the uncovered jar after 24 hrs?
Maggots appeared on the surface of the meat
26
what was different in Redi's second experiment?
The meat was covered with wire gauze
26
what was the result of covering the meat with wire gauze?
No maggots appeared on the meat
26
what conclusion did Redi draw from his experiment?
Maggot do not arise spontaneously; they come from fly eggs
27
what was the significance of Redi's experiment in scientific history?
It provided the first experimental evidence against spontaneous generation
27
What was Lazzaro Spallanzani trying to disprove with his experiment?
The theory of spontaneous generation
27
what did Spallanzani do in his experiment with infusions?
He boiled the infusions and placed it in a closed flask
28
what happened when Spallanzani incubated the boiled infusion in a closed flask for 24 hrs?
No microorganisms (animacules) were present
29
what happened when the infusion was placed in an open flask and incubated for 24hrs?
Microorganisms appeared
30
what conclusion did Spallanzani draw from his experiment?
Microorganisms come from the air and do not spontaneously generation
31
how did Spallanzani's experiment build upon Redi's work?
He extended the idea that life does not spontaneously arise, applying it to microscopic organisms
32
Why did Spallanzani boil the infusion in his experiment?
To kill any preexisting microorganisms
33
Who later improved upon Spallanzani's experiment to definitively disprove spontaneous generation?
Louis Pasteur
34
How did critics of spallanzani's experiment argue against its conclusion?
They claimed that boiling destroyed the vital force needed for spontaneous generation
35
Who developed the first air tight food preservation technique?
Nicolas Appert
36
Who was Francois Appert?
He was the originator of the canning process for food preservation
37
what method did François Appert use for food preservation?
He used airtight containers and heat to prevent the presence of microorganisms (animacules)
38
Why airtight sealing important in canning?
It prevents the entry of microorganisms, keeping the food preserved
39
what is an example of product that cannot be sterilized at high temperature?
Some heat -sensitive food products
40
how does the principle of canning relate to modern food preservation methods?
modern techniques use similar principles but with more discipline and precision
41
what gas did Priestly, Cavendish and lavoisier study?
Oxygen
42
Why is oxygen essential for life?
Microbes rely on oxygen for growth and its presence or absence affects fermentation processess
43
How does heating and sealing food containers prevent spoilage?
Heating kills microorganisms and sealing prevent new ones from entering
44
What principle did these scientists explain?
The principle behind microbial growth, fermentation, and chemical reactions involving gases
45
What did the demonstration involving aspirating air through a cotton tube show?
It showed that microorganisms from the air could be trapped in cotton and observed under microscope
46
What happened when the cotton was placed in alcohol and observed under a microscope?
Microscopic "organized bodies" (microorganisms) were found
47
What conclusion was drawn from this experiment?
Microorganisms come from the air
48
What was the purpose of boiling the broth in Pasteur's experiment?
To kill any pre existing microorganisms
48
What was the role of the swan-neck flask in Pasteur's experiment?
It allowed air to enter but prevented microorganisms from reaching the broth
49
What theory did Pasteur's experiment disprove?
The theory of Spontaneous generation
49
What happened when the broth was left in an intact swan-neck for three days?
No microorganisms appeared in the broth
50
What happened when the swan-neck was broken off?
Microorganisms entered and the broth became contaminated
51
What key idea did Pasteur's experiment support?
Microorganisms come from other microorganisms in the air, not from spontaneous generation
52
What role did Louis Pasteur play in fermentation?
He studied fermentation and discovered the importance of electing proper microbes for beer and wine production
53
Why is heating juices important in food production?
It removes undesirable microbes
53
What disease affected silkworms and what was its cause?
Pebrine caused by protozoa
53
What is the ideal temperature and duration for pasteurization?
62.8 oC for 30 minutes
53
How is pasteurisation widely used today?
Modern pasteurisation involves ultra-pressure techniques at 142 oC for 0.5 sec
53
What was the conclusion regarding controlling Pebrine?
Use disease-free caterpillars for breeding stock
53
What is anthrax and which organisms does it affect?
A disease affecting cattle and sheep caused by Bacillus anthracis
53
How was Bacillus anthracis identified as the cause of anthrax?
The bacteria were isolated from the blood of diseased animals
54
What important discovery did Ignaz Semmelweis' discovery?
He discovered that handwashing drastically reduced the incidence of puerperal fever in obstetrical clinics
55
What was the significance of Semmelweis' discovery?
It supported the Germ Theory and led to the development of aseptic techniques
56
Why was germ theory not widely accepted at the time of Semmelweis' discovery?
It has not yet gained popularity in the medical community
56
How was puerperal fever transmitted in hospitals?
Through medical personnel using unhygienic practices
57
What was Joseph Lister's contribution to medical science?
He developed antiseptic techniques using chemical disinfection to prevent infections
58
How did Joseph Lister's work build upon that of Ignaz Semmelweis?
He expanded Semmelweis's ideas by developing sterilization techniques and antiseptic surgery
59
What product was named in honor of Joseph Lister?
Listerine, an antiseptic mouthwash
60
Why is Robert Koch known as the "founder of bacteriology"?
He provided experimental evidence proving the existence of bacteria as disease-causing agents
61
What prestigious award did Robert Koch receive for his work?
Nobel prize for his research on tuberculosis
62
What was the first step in Koch's Postulates?
The suspected microorganism must be found in all diseased organisms but absent in healthy ones
63
Why must the microorganism be absent in healthy organisms in koch 's experiment?
To confirm that the microorganism is specifically associated with the disease and not a normal part of healthy organisms
64
What is the purpose of isolating the microorganism in pure culture?
To ensure that only a single type of microorganism is studied and to confirm its role in causing disease
64
What happens when the cultured microorganism is introduced into a healthy organisms?
The previously healthy organism should develop the same disease as the original infected host
65
Why is it important to re-isolate the microorganism from the newly infected host?
To verify the same microorganism caused the disease, confirming its role as the infectious agent
65
What are some limitations of Koch's postulates?
some microorganisms cannot be cultured in a lab
some diseases have multiple causative agents
some infected individuals remain asymptomatic
65
How does Koch's experiment using rats help prove the germ theory of disease?
It demonstrates that specific microorganisms cause specific diseases by fulfilling all four postulates
66
what diseases did Robert Koch use his postulates to study?
Tuberculosis, cholera and anthrax
66
How do Koch's postulates establish a cause and effect relationship between microbes and disease?
By systematically proving that a specific microorganism is responsible for a disease through isolation, culturing, inoculation and re-isolation
66
what role does inoculation play in the rat experiment
Inoculation introduces the isolated microorganism into a healthy organism to observe whether it causes the same disease
67
How did Pasteur attenuate the bacteria in his experiment?
By isolating the bacteria in the lab for 8 weeks
67
What disease did Louis Pasteur study in his immunization experiment?
Chicken cholera
68
what happened when healthy chickens were infected with aged bacterial culture?
They remained healthy, despite expectations of death
69
What was the outcome when the experiment was repeated using freshly isolated bacteria?
chickens previously exposed to the old culture remained healthy, while new healthy chickens died
70
what was the main conclusion from Pasteur's experiment?
Attenuated bacteria lose virulence but retain antigenicity, leading to immunity
71
what other diseases did Pasteur apply this principle to?
Anthrax and Rabies
72
What is the significance of Pasteur's experiment in modern medicine?
It led to the development of vaccines using attenuated culture
73
What is Tyndallization?
A method of fractional sterilization using repeated heating and cooling
74
what did John Tyndall's experiment demonstrate?
Some bacteria exist in 2 phases: Thermoresistant (spores) and thermolabile (vegetative cells)
75
why did sterilization fail in some cases during Tyndall's experiment?
Because spores survived initial heating and later germinated
76
what type of bacteria did Tyndall observe as thermoresistant?
Bacillus spp and Clostridium spp
