Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

microbiology > chapter 3 microscopy > Flashcards

chapter 3 microscopy Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

define light microscope that uses light to observe a specimen

A

light microscope

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

define light microscope

A

uses light to observe a specimen

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

uses two lenses to magnify the image

A

compound microscope

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

define the compound microscope in your words

A

uses two lenses to magnify the image

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

what is a objective lens? and how much does it magnifies?

A

lens closest to the specimen, magnifies between 10x-100x

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

what is ocular lens?

A

it is the eyepiece, magnifies by 10x

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

calculating magnification:
how do you calculate compound microscope

A

total magnification= objective lens x ocular lens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a resolution, define it.
two points can be distinguished if they are how much of a distance apart.

A

ability to distinguish fine detail and structure, and distinguish 2 points a certain distance apart.

  • two points can be distinguished if they are at least 4 nm apart.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

resolution :
True or false.
Light must pass between 2 objects for them to be seen as 2 separate things.

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

resolution:
true or false.
does not need light of a short-enough wavelength to fit between them, as it will automatically appear as 1 objct

A

false

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

what is the resolution general principle

A

the shorter the wavelength, the better the resolution.

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

3 (characteristics ) of electron microscope

A

uses electron instead of light
electrons travel in much shorter waves than light
resolving great power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

this microscope allows us to view viruses and internal cell structures, and allows greater magnification

A

electron microscope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the two types of electron microscope?

A

scanning and transmission

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

transmission

A

to see internal structures
- very thin slices, can be cut from sample- thin sections
-samples generally stained with a metal to make structure opaque to electrons.

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

scanning

A

to see surfaces less powerful

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

what is atomic force and is it a part of electron microscope?

A

atomic force is to see molecules, uses thin metal probe to scan a specimen that has bumps and depressions

and not electron microscope.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

human eye can see an object about ??

A

0.2 mm

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

compound light microscope can view an object about

A

0.2 ûm

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

electron microscope can view an object about

A

2 nm

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

chromophore

A

stains are composed of positively and negatively charged ions, one of which is coloured

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

what is a simple stain

A

only one dye used to highlight the entire microorganism

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

what are the four simple steps (simple stain)

A

1) smear sample on slide
2)fix with heat (heat is added, so the specimen can stick into the glass)
3) add stain
4) wash, dry, and view

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

how do stains work?what is the charge on the outer surface?

A

bacteria have a net negative charge on their outer surface

charge attracts stains with positively charged chromophores, and repels stains with negatively charged chromophores.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

positive stains, define the characteristics

A

stain will bind to the bacterium
bacterium appears coloured
background appears clear
ex: crystal violet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

negative stains, define the characteristics

A

will not bind to the bacterium
bacterium appears clear
background is colored
ex:nigrosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

differential stains, define it

A

react differently with different bacteria, thus can be distinguish between them
ex: gram stain

  • differentiates bacteria based on the structure of the cell wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

bacteria with a thick cell wall retain the primary stain crystal violet an appear purple which is what?

A

gram positive example : streptococcus pyogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

bacteria with a thin cell wall lose crystal violet during destaining, take on the color of the counterstain safranin and appear pink

A

gram negative example: e.coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

define what the definition of spore stain is

A

stains an internal structure of some bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

primary stain colors endospores green

A

spore stain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is the primary stain color of spore stain

A

endospores green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what does counterstain (safranin) colors the rest of the cell? and name an example

A

it colors it pink, an example would be bacillus anthracis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

what is a flagella stain?

A

flagella stain, stains the external structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what does mordant do to flagella?

A

it thicken the flagella so they can be observed under a light microscope.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

acid-fast stain
: define what it does

A

it detects the presence of waxy compound in cell wall and used to identify the genus mycobacterium

such as mycobacterium tuberculosis
mycobacterium leprae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

acid-fast-stain:
mycobacterium cell wall retains the dye _____

A

carbol fuschin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

counterstain with methylene blue stains non- acid bacteria and tissues green

A

false, tissues blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

capsule stain:
define what it is

A

detects a thick layer of polysaccharide outside the cell and this is a capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

capsule stain a negative stain colours the what?

A

background

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

capsule stain:
the positive stain colors the what?

A

cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

the capsules does not take up most dyes and remains ______

A

colorless

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

define the characteristics of prokaryotes

A

dna is not enclosed within a nucleus
one circular chromosome
they lack membrane-enclosed organelles
single celled organisms such as bacteria and archae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

define the characteristics of eukaryortes

A

dna is found in the nucleus :surrounded by a nuclear membrane
Dna is arranged as multiple chromosomes
they have membrane-enclosed organelles
examples are protozoa,fungi,animals,plants,algae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

the bacteria morphology (shape)
coccus
bacillus
vibrio
spirillum
spirochete

A

coccus- cocci- spherical
bacillus- rod shaped
vibrio- curved
spirillum- spiral shaped
spirochete- corkscrew shaped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

external structures
capsules and slime layers
sticky, gelatinous layer is what to the cell?

A

it is external to the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

capsules and slime layers are composed of what?

A

polysaccharide, protein or both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

what is the definition of capsule

A

if the layer is organized and firmly attached to the cell wall it is known as a capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

if the layer is organized and firmly attached to the cell wall it is a

A

capsule

50
Q

if the layer is unorganized and loosely attached to the cell wall it is known as a

A

slime layer

51
Q

define what a slime layer is

A

if the layer is unorganized and loosely attached to the cell wall

52
Q

in some bacteria capsules a play a role in virulence which is a protection against

A

phagocytosis

53
Q

protection against phagocytosis example is streptococcus pneumoniae, with a capsule and without capsule causes what

A

with a capsule,it causes a disease, without a capsule causes no disease

54
Q

True or false.
slime layers often allow bacteria to attach to surfaces, such as medical implants, water pipes and teeth

A

true

55
Q

how are polysaccharide slime made?and what happens when it attaches to teeth ?

A

from sucrose , attaches to teeth which can lead to cavities

56
Q

what are the four bacterial cells typical arrangements of flagella

A

monotrichous
Lophotrichous
amphitrichous
peritrichous

57
Q

define what these terms mean
1)monotrichous
2)Lophotrichous
3)amphitrichous
4)peritrichous

A

1) a single polar flagellum
2) two or more flagellum originating from one pole
3) tufts of flagella originating from opposite poles
4) flagella distributed all over the cell

58
Q

Flagellar motility:
flagella turn causing cell to move in one direction, which is also referred to as

A

run

59
Q

periodically flagella reverse direction causing a random change in direction which is also referred to as

A

tumble

60
Q

when a cell senses it is moving toward an attractant, it ___ less frequently, so the ___ in the direction of the attractant are longer.

A

tumble and run

61
Q

flagella allow chemotaxis:
movement toward or away from a stimulant
toward a nutrient is called what
away from a toxin

A

is called an attractant
repellent

62
Q

define what fimbriae and pili are

A

short, hair like appendages and hollow

63
Q

what is a fimbriae, name an example

A

allow the cell to adhere to surfaces
contribute to pathogenecity (the possibility to cause a disease)
some strains of E.coli have fimbriae that allow them to attach to the intestinal wall

64
Q

define what pili means

A

allows attatchment of two bacteria to each other
involved in transfer of genetic material between bacteria
example would be e.coli sex pilus

65
Q

true or false:
bacterial cell wall:
-semi-rigid structure giving shape to the cell
major function is rupture the cell-protecting it against environmental changes
useful in the identification of bacteria, for example: the gram stain

A

point number 2 is wrong, the major function is to prevent the rupture of the cell.

66
Q

what is the bacterial cell wall composed of?

A

it is composed of the complex macromolecule which is called peptidoglycan

  • it is a mesh like structure composed of polysaccharide and amino acids
    -polysaccharide portion is composed of two alternating monosaccharides

N-acetyl glucosamine (NAG )
N-acetyl muramic acid (NAM)

peptide portion composed of short chains of amino acids

67
Q

a generalized view of peptidoglycan

A

polysaccharide chains run parallel
peptide chains link polysaccharides together
forms a mesh-like net surrounding the cell

68
Q

the gram positive cell wall is made of what?

A

made of peptidoglycan outside the plasma membrane and they also contain teichoic acids

69
Q

wall teichoic acids in gram positive cell wall is attached to what

A

peptidoglycan

70
Q

lipoteichoic acids in gram positive cell wall is attached

A

attached to plasma membrane and extend through the peptidoglycan

71
Q

Can gram positive bacteria have only one or two membrane

A

one membrane which is the cytoplasmic membrane

72
Q

describe what the gram negative cell wall is

A

thin peptidoglycan layer that is sandwiched between two membranes
outer membrane made of lipids (phospholipids),proteins, and lipopolysaccharides(LPS)

73
Q

Polysaccharide portion of LPS is composed of O-sugars in gram negative cell wall? which is useful for establishing gram negative bacteria

A

true

74
Q

Lipid portion of LPS is toxic, true or false

A

true

75
Q

the gram negative cell wall is also reffered to as

A

endotoxin

76
Q

what does exotoxin mean and endotoxin?

A

exo is meant to do harm while endo is not meant to do harm

77
Q

how does gram stain work?
gram positive cells explain…
gram negative cells explain…

A

thick peptidoglycan traps the crystal violet and appears purple

thin peptidoglycan does not trap Crystal violet and the other membrane gets disrupted by alcohol and the crystal violet is washed away, safranin counterstain stains the cell pink.

78
Q

what are the components of peptidoglycan that makes them special?

A

completely different from anything found in animal cells
many antibiotics have been discovered that act against peptidoglycan

example is penicillin which inhibits products of peptidoglycan
also degraded by one of our natural diseases:lysozyme
-found in tears , saliva, mucous

79
Q

plasma membrane is composed of what

A

phospholipid bilayer

80
Q

what does the cell membrane do(name one )

A

seperate the interior (cytoplasm) from the outside environment
- serves as a semi-permeable barrier
-selectively allows inflows and outflows of the materials
exists in a semi fluid state

81
Q

antimicrobial agents define them

A

alcohols disrupt the membrane
can be used as a disinfectant

82
Q

internal components:
Cytoplasm define the characteristics of it

A

the substance inside the plasma membrane
about 80% water
contains most of the stuff needed for life such as suhar,amino acids, nucelotides,enzyms, and some structional structures

83
Q

this contains the bacterial chromosome

A

the nucleotid

84
Q

all genetic information required for cell’s structures and functions

A

the nucleoid

85
Q

this internal component is not surrounded by a nuclear membrane

A

the nucleoid

86
Q

Define the characteristics

  • this may also contain plasmids, which smaller double stranded dna molecules, also contain non-essential-genes like antibiotic resistance
A

the nucleoid

87
Q

define the definition of ribosomes

A

the site of protein synthesis (translation)

88
Q

is ribosome only made of protein?

A

no, it is also made of ribosomal RNA (rRNA)

89
Q

what are the two parts of ribosomes ? and how much does it complete together ?

A

the two parts of ribosomes are 30S subunit and 50S subunit, together they make 70S ribosome

90
Q

Ribosomes of bacteria differ from Eukaryotic ribosomes

A

yes they do differ as, eukaryotes have 80 ribosomes, several antibiotics target bacterial ribosomes

91
Q

several antibiotics target bacterial ribosomes

A

prevent the bacteria from making new proteins

92
Q

define storage granules (inclusion bodies)

A

usually deposits or granules of nutrients, stored for later use

examples :
-sulfur granules
-polysaccharides
-lipid inclusions
-enzymes
-magnetite

93
Q

variety of inclusion bodies occur in different bacterial species- can serve as a basis for identification

A

storage granules (inclusion bodies)

94
Q

define what endospores

A

formed only by some Gram positive bacteria

95
Q

special resting structure-allows bacteria to enter dormant state

A

endospores

96
Q

endospores

A

extremely durable (resists heat, desiccation, chemicals, radiation, etc)
- some endospores can survive in boiling water for hours
remains dormant until good growth conditions occur- can form a new population

97
Q

what does bacillus anthracis cause?

A

causes anthrax

98
Q

what does clostridium botulinum cause?

A

causes the food borne illness botulism

99
Q

name the steps of sporulation

A
  1. cell replicates its DNA
  2. septum forms, dividing the cell into unequal compartments
    3.larger compartments engulfs the smaller
    4.peptidoglycan and other protective material forms around the forespore (spore coat)
    5.finished spore is freed from the mother cell as the mother cell dies.
100
Q

what are the internal components?

A

cytoplasm
the nucleoid
ribosomes
storage granules
endospores
sporulation

101
Q

define the characteristics of eukaryotic cell structure
includes microorganisms
higher organisms

A

includes microorganisms : Algae, fungi, protozoa
Higher organisms : Plants and animals, larger and more complex than prokaryotes , genetic material is housed in a nucleus
-membrane bound organelles

102
Q

is the cytoplasmic membrane the same basic structure as in prokaryotic cells?

A

yes they do have the same cytoplasmic membrane

103
Q

what does cytoplasmic membrane contain?

A

contains phospholipids, proteins, and sterols, sterols make membrane relatively rigid compared to bacteria

104
Q

true or false.
Not all eukaryotes have a cell wall?

A

true

105
Q

define the characteristics of cell wall

A

not all eukaryotes have a cell wall
- allows endocytosis
it is simple structure compared to bacteria made of cellulose (algae,plants)
and chitin (fungi)

106
Q

define the characteristics of cytoplasm.

A

substance inside the plasma membrane, but outside the nuclear membrane

107
Q

cytoplasm has complex internal structure, what is it called?

A

cytoskeleton

108
Q

protein filaments on the inside of the plasma membrane, provides support and shape & transports substances through the cell

A

cytoskeleton

109
Q

Ribosomes:
- larger and heavier than bacterial ribosomes (eukaryotes)

A

80s

110
Q

made of strands of the protein actin, often interact with strands of other proteins

A

microfilaments

111
Q

long, hollow cylinders made up of many molecules of the protein tubulin. Tubulin consists of two subunits, x tubuin , and b tubulin.

A

microtubules

112
Q

intermediate filaments

A

made up of fibrous proteins organized into tough, ropelike assemblies that stabilize a cells’ strcuture and help maintain its shape

113
Q

membrane bound organelles

A

structures with specialized functions and not present in bacteria

114
Q

what are some-examples of membrane bound organelles

A

nucleus, mitochondria, chloroplasts

115
Q

what is a nucelus?

A

compartment holding genetic material

116
Q

what is mitochondria?

A

site of energy producion

117
Q

what is chloroplasts?

A

site of photosynthesis in algae and plant cells

118
Q

appendages external to the cell are

A

flagellum and cilia

119
Q

what is a flagellum and cilia?

A

long flexible projections that contain protein and cytoplasm

-move in whipped likefashion which can be used in motility and sweeping material past stationary cells

120
Q

define the characteristics of prokaryotic vs eukaryotic flagella , distinguish between the two

A

prokaryotic flagella:
- made of protein subunits
-protrude through the cell wall and cell membrane
-stiff, twirl like propeller

eukaryotic flagella:
covered by cell membrane
whipping action
a bundle (9+2) of microtubules (made of protein)

microbiology (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions