Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Hsci 212 > Week 2 > Flashcards

Week 2 Flashcards

1
Q

How is microbiology defined

A

-by organisms studied
Or
-by the techniques used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What types of organisms are studied in microbiology

A

Microscopic
-bacteria
-viruses
-yeasts (fungi)
-protozoans
Macroscopic
-worms
-moulds (fungi)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Before germ theory people thought disease was spread through…

A

Miasma theory
-bad air/ harmful vapours carried disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Who is Antoni van Leeuwenhoek

A

-Dutch
-made simple microscopes
-examined water and saw fungi, algae, and single cell protozoa which he called animacules
-these were later called microorganisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Who is Joseph lister

A

-British surgeon
-believed sepsis was caused from pollen like dust
-used disinfectant to improve survival after surgery
-disinfect skin and surgical tools

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 4 of Koch’s postulates

A
  1. Suspected agent must be present in every case of the disease
  2. The agent must be isolated and grown in a pure culture
  3. The cultured agent must cause disease in a healthy experimental host
  4. The same agent must be resonated from the experimental host
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some faulty assumptions of Koch’s postulates

A
  • pathogens are only found in diseased individuals
  • all healthy subjects are equally susceptible to disease
  • all pathogens can be grown in a pure culture
  • animals are reliable human model
  • pathogens tend to cause same disease presentations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the molecular Koch’s postulates

A
  1. The phenotype should be associated only with pathogenic strains of a species
  2. Inactivation of suspected genes associated with pathogenicity should result in measurable loss of pahogenicity
  3. Reactivation of gene should restore phenotype
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

List the microbes we are studying and their respective treatment

A
  • viruses - antivirals
  • bacteria - antibiotics
  • fungi - antifungal
  • parasites - antipatasitics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the two types of parasites

A

Protozoa and Helminths(worms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Tell me about bacteria

A

-About 1um
- prokaryotes
- many are good some are bad
- make ought, cheese, and keep intestines happy
- food poisoning among other diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Tell me about viruses

A
  • 10-100 nm
  • many shapes
  • acellular
  • rely on host cell for survival/replication
  • can infect bacteria (bacteriophage)
  • many serious infectious diseases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Tell me about fungi

A
  • many different sizes from a few um to several cm
  • different shapes (single cell yeasts or multicellular molds)
  • Eukaryotic
  • Heterotrophic: dependent on organic matter for nutrition
  • important for decomposition and fermentation
  • many diseases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tell me about parasites

A

-Size varies
- different shapes (unicellular Protozoa or multicellular helminths)
- eukaryotic
- often rely on host for survival
- often complex lifecycles, may have multiple hosts
- cause many mild and severe diseases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Tell me about Ignaz Semmelweis

A

-Hungarian doctor
-noticed larger death rate where physicians and med students assisted with birth compared to the midwife ward
-friend got what appeared to be childbed fever after getting cut during autopsy
-believed something was transmitted which caused the illness
-made doctors wash hands before childbirth
- deaths went down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Pathogen

A

A microbe that can cause an infectious disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Steps for a pathogen to cause an ID

A
  1. Maintain a reservoir
  2. Be transported to and enter host
  3. Adhere to, colonize, and/or invade host cells or tissue
  4. Initially evade host defenses
  5. Multiply and complete life cycle
  6. Mechanically or chemically damage host
  7. Leave host and return to reservoir or new host
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does it mean for a pathogen to maintain a reservoir

A

To circulate at low levels in a susceptible host like influenza
Or to maintain population in a non-susceptible host (a zoonotic host for example)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Ticks are hosts for

A

Lyme disease and Rocky Mountain fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Bats are hosts for

A

Rabies, Ebola, nipah, sars-cov

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Rats are hosts for

A

Hanta virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How can a pathogen be transported to and enter a host

A

Direct contact
- fecal-oral
- droplet
- aerosols
- sexual contact

Indirect contact
- Fomites: inanimate objects that can harbour pathogens

Vectors
- insect vectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are adhesins on bacteria

A

Molecules that help them attach to tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Do ALL pathogens enter cells

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How do viruses enter their hosts
Specific receptors
26
Some bacteria pathogens attach to each other to form a…
Biofilm
27
Ways pathogens can evade host defenses
Capsules - polysaccharide coat in bacteria which decreases probability of being eaten by immune cells Reproducing inside host cells Changing surface antigens to stay ahead of detection
28
How do viruses multiply
Hijacking cell machinery to produce new virus
29
How do bacteria multiply
Binary fission
30
How do Protozoa multiply
Both sexually and asexually
31
How do pathogens damage hosts
Toxins
32
The 2 types of toxins we know
Endo and exotoxin
33
What is an exotoxin
Small protein toxins which damage hosts and are actively released
34
What is an endotoxin
Part of bacterial cell wall which is generally released when the cell dies, elicits strong immune response which damages hosts
35
Reservoirs of IDs
Animal reservoirs - zoonosis: disease spread from animal to human - acquired from direct contact with animal, waste, or product. As well as blood sucking arthropods Human carriers -asymptomatic individuals Nonliving reservoirs - soil, water, food….
36
Is pathogenicity the rule or the exception for bacteria
The exception, we have many bacteria that live inside us and coexist and help, also tons of bacteria assist with food.
37
What is microbiota
Community of microbes in different sites of an individual
38
What is a microbiome
Aggregate of genomes and genes of microbiota
39
What is dysbiosis
Change in structural or functional configuration of the microbiota that disrupts homeostasis with host and microbial community and leads to adverse affects for host
40
What makes something a prokaryote
Lack of nucleus, single circular chromosome in nucleoid, smaller, usually lack membrane bound organelles, may have plasmids (extrachromosomal DNA)
41
How do bacteria transfer genes
Vertically: to the next generation through asexual reproduction Horizontally: transferring genetic info to other organisms in the same generation through the use of plasmids.
42
What is the bacteria cell wall made of primarily
Peptidoglycan
43
What is peptidoglycan made of
Proteins(peptide) and sugars(glycan)
44
What is the difference between gram-negative and gram-positive cell walls
Gram positive have a thick peptidoglycan wall and gram negative have a thin peptidoglycan layer behind the outer cell membrane
45
Bacteria are often categorized based on what
The nature of their cell wall
46
Gram stains are what
A process which stains an organism based on the characteristics of their cell wall
47
A gram-negative bacteria will stain what colour after a gram stain
Pink or red
48
A gram-positive cell will stain what colour after a gram stain
Purple or blue
49
What are the different shapes of bacteria
Coccus, bacillus, vibrio, coccobacillus, spirillum, spirochete
50
Coccus has what shape
Sphere
51
Bacillus has what shape
Pill
52
Vibrio has what shape
Comma
53
Coccobacillus has what shape
Combination of spheres and rods
54
Spirillum and spirochete have what shape
Spirals
55
A single spherical bacteria would be called a
Coccus
56
A bacteria which looks like a pair of spheres would have the prefix followed by
Diplo- coccus
57
A bacteria which looks like a group of four spheres would be called a
Tetrad
58
A bacteria which looks like a chain of spheres would have the prefix followed by coccus
Strepto-
59
A bacteria which looks like a cluster of spheres would have the prefix followed by coccus
Staphylo-
60
what is pathogenicity
Ability of a microorganism to cause disease
61
What is virulence
The degree of pathogenicity
62
2 factors which affect the outcome of the host-pathogen interaction
State of host health - age - nutrition - immune systems Virulence of pathogen - infectivity - invasiveness - toxigenicity
63
What is the ID50
Median infectious dose - number of pathogen cells or visions required to cause active infection in 50% of “infected” -is an indicator of virulence
64
What is the LD50
Median lethal dose -number of pathogen cells or virions required to kill 50% of infected animals
65
Can a bacteria be virulent but not pathogenic
No since to be virulent you must be pathogenic
66
Can bacteria with low infectivity be virulent
Yes since virulence is just the degree of pathogenicity, it doesn’t need to be high just needs to be there
67
List some general virulence factors
Extracellular enzymes Toxins Factors which prevent phagocytosis
68
What are extracellular enzymes with examples
Secreted by pathogen Dissolve structural chemicals in body Eg -hyaluronidase and collagenase — break down epithelial cells and collagen - coagulase and kinase — form clot and dissolve clot
69
Toxins are
Chemicals that harm tissues or trigger immune response which causes damage 2 types exo and endotoxins Toxemia
70
Toxemia refers to
Toxins in the bloodstream that are carried beyond the site of infection
71
Factors which prevent phagocytosis are
Bacterial capsules - not recognized as foreign - difficult to engulf Antiphagocytic chemicals -prevent fusion of lysosomes and phagocytic vesicles -Leukocidins directly destroy phagocytes
72
What is an Endospore
A dormant tough non-reproductive structure which allows bacteria to survive harsh conditions
73
What are biofilms
Structured communities of microorganisms that are embedded in an extracellular matrix and adhere to a surface -can form on tissues and foreign bodies -allows bacteria to withstand environmental stresses and antimicrobial agents

Hsci 212 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions