Module 1: History of Microbiology and Microscopy Flashcards

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1
Q

what are Eukaryokes

A

large multicelluar microorganisms

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2
Q

what is microbiome

A

coexisting vast number of colonizing microorganisms
- vast majority are not harmful to us but play essential roles in providing nutrients, carrying out essential transitions and cycling of nutrients

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3
Q

what is the average size of microorganisms

A

0.2 mm and smaller

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4
Q

are paracites considered microorganisms

A

yes

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5
Q

what other entitities are considered micro organisms even though they cant live on their own

A

viruses and prions

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6
Q

how do we know that cellular life on earth is all related to one another

A

DNA sequencing analysis allows for comparisons of the DNA sequence changes between each species
- many scienctists have worked to obtain sequences from the same gene From every known organism and shared it on a data base

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7
Q

what is is called to obtain sequences from the same gene?

A

phylogenetic analysis

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8
Q

what are the three domains of life

A

bacteria, archaea, and eukarya

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9
Q

what are viruses

A
  • the smallest of the microbs
  • they cannot replicate on their own, they require host cells to replicate
  • they can encode their own genetic DNA or RNA
  • we cannot determine how related they are to cellular life becasue they do not share genes that are consistenly in other life forms
  • viruses can cause a number of human diseases and cancers
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10
Q

what are viroids

A
  • require host cells to replicate
  • they replicate their genomes (single stranded RNA)
  • spread from cell to cell
  • they are limited to plants
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11
Q

what are satellites

A
  • a defective virus
  • they encode a nucliec acid enclosed in a protein shell and infect new cells on their own
  • they cant replicate themselves unless the cell they are in is coeffected with a specific virus that provides enzymatic help to complete their life cycle
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12
Q

what is a prion

A
  • proteins encoded by the host
  • infectious variants of this protein misfold to create a new form that has a tendency to bind to other copies of the normal protein and cause them to misfold
  • this can cause normal copies to fold
  • this can effect foods and if foods are consumed by humans it can begin the process in a human host
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13
Q

what was a major player of early life

A

RNA - serving as both a genetic informer and carrying on essential catalytic functions

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14
Q

all living cells have a collective set of atributes

A
  • they are made up of cells
  • ability to respond to environmental changes
  • ability to grow and develop
  • use energy and undergo metabolism
  • regulate cellular metabolic activites
  • reproduce
  • undergo biological evolution
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15
Q

which of the collective set of attributes is most important

A

biological evolution

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16
Q

what can all life forms be traced back to?

A

LUCA
L last
U universal
C common
A ancestor

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17
Q

what was the first domain to exsist

A

evidence points to Bacteria and Archaea
with eukaryotes developing later
- both cells are similar with lack of internal structure
lack defiend nucleus - prokaryotic cells

18
Q

what do eukaryotic cells contain

A
  • membrane enclosed nuclei
  • mitochondria and endoplasmic reticulum golgi apparatus chloroplasts
  • evolved from common ancestor of archaea
  • likely caused from relationship between archaea ancestors and bacteria
  • protists, algae, slime, molds water molds and fungi
19
Q

what was the ealiest microscope able to see

A

single celled organisms

20
Q

what created the earliest microscop

A

Antony Van Leeuwenhoek
- not a trained scientist and took the world a long time to take him seriously

21
Q

what were two major milestones in microbiology

A
  1. the development of a systematic set of proofs for determining whether a specific organism was responsible for specific disease - robert koch
  2. development of a series of effective vaccines - Louis pateur
22
Q

what did the need to obtain pure culture do for microbiology

A

development of newer and more refined media growth tequnics

23
Q

what did louis Pasteur do

A
  • disproved spontaneous generation
  • created succeful anthrax vaccine
  • described chirality of chemical bonds
  • developed pasteurization to preserve french wine
  • developed germ theory
  • developed attenuated
  • developed vaccine for rabies
24
Q

what is the light microscope

A
  • the first created
  • utilize lenses to bend light beams and focus and magnify samples
  • different lenses will have different focuses and magnifications
  • general sizes - 10x 40x and 100x
25
Q

what are bright field microscopes

A

most common light microscopes
- source of light shines through the bottom through the sample and image is visible by contrast background

26
Q

what is resolution

A

the ability to distinguish a point from a neightbourhouring point
- poor resolution means that objects bluur together
- for light miscroscopes the resolution is indicatied wavelength of light
- 0.2 um

27
Q

what is contrast

A
  • distinguishing the object from surrounding ones
  • treat the sample with a stain or combination of stains
  • the stain needs to be able to bind to specific parts of the sample to make it stand out
  • one downside is it often kills the sample being stained
28
Q

what is dark feild microscopy

A

imaging on a dark feild microscope
- dark background
- light is shinning on the sample instead of up through the sample

29
Q

what is phase contrast microscopy

A

light passes through a living cell but will be slightly delayed
- amplifies small differenced so that light passing through an object will not cancel out light that didnt pass through

30
Q

what is differential interference contrast microscope

A

uses differences in refractice indices and thickness of different parts of specimen to create an image
- use two beamd with right angeled lights
- one light passes through specimen while the other passes through delayed
- goes through prism to create three d object

31
Q

flourescent microscopes

A
  • some materials can absorb energy from one source and become excited and emit light
  • illuminate the object with defined wavelength light beam
  • flourescent dyes excite sample and they emit their own colour
32
Q

confocal microscopy

A

creates shape 3d images
computer collects image data
scanning laser produces an image
- creates a series of flat images and stacks them to create 3d object

33
Q

fixation and staining

A
  • often stuck on glass slides to allow flooding and washing steps
  • heat and chemical fixation are most common
  • heat dries the sugars and sticks cells to glass
  • chemicals imobolize samples (fermaldehyde)
34
Q

staining has two dyes

A

basics - positively charged groups - bind to negatives
acidic dyes - negatively charged sticks to positive groups

35
Q

what is the most used stain

A

gram stain
- used to differentiate gram positive and gram negative

36
Q

electronic microscopes

A

beams of electrons are used instead of light beams
- electrons travel in waves
- wavelength is shorter than visible light
- 1000x better than light
-

37
Q

transmission electron microscopes

A

shoot beams through the sample and image is viewed by its ability to block out electrons, much like bright feild light microscopes

38
Q

staining in electron microscopes

A
  • uses heavy metals because they are sufficient at blocking electrons and are often sprayed into other sampled to show them better
39
Q

what are potential draw backs of electron microscopy

A

samples must be viewed in a vaccum as electrons do not travel through air
so the samples need to be dehydrated
-

40
Q

scanning electron microscopy

A

electrons are bounced off at an angle
the electron beams scans focuse on beams of electrons along the samples and image is generated

41
Q

scanning probe microscopy

A
  • small prob scans along the surface of the sample specimen
  • the prob is designed to move up or down in response to the contours or other properties on the surface
  • scans to create a contour map = atomic force microscope
  • does not require dehydrated samples or use of high vaccuum environement