Lecture 6 Flashcards
1
Q
Is the cell wall living or non living?
A
non living
2
Q
is the cell wall extracellular?
A
no
3
Q
Is the cell wall an integral part of the cell
A
yes
4
Q
is the cell wall the same thing as the glycocalyx?
A
no
5
Q
how much of the dry weight of a cell is its cell wall?
A
20-40%
6
Q
what is plasmoptysis?
A
bursting of the cell
osmotic lysis
7
Q
what are the general properties of the cell wall?
A
non living
not extra cellular
is 20-40% of the dry weight of the bacteria
8
Q
What sort of osmotic conditions do bacteria live in?
A
low osmotic conditions
9
Q
Does water flow into or out of the cell?
A
into the cell
10
Q
Use the terms hypertonic, isotonic, and/or hyoptonic to describe a cell and its ideal environment
A
The cell is slightly hypertonic to its environment
the environment is slightly hypotonic to the cell
11
Q
you have 2 samples. sample A is hypertonic to sample b
which has a lower solute concentration?
A
sample b does
12
Q
does the cell wall shrink during plasmolysis?
A
no
13
Q
does the cell membrane shrink during plasmolysis?
A
yes
14
Q
What shape would bacteria be without a cell wall?
A
spheres
15
Q
what are the functions of the cell wall?
A
prevents plasmoptysis
gives shape
provides an anchor for flagella
acts as a sieve
16
Q
what is a sieve?
A
a filter, semipermiable membrane
17
Q
does the cell wall allow things to pass through it?
A
yes but it is selective and won’t let everything through
18
Q
what is murein?
A
a peptido glycan
the backbone of the cell wall
19
Q
What does NAM stand for?
A
N-acetylmuramic acid
20
Q
What does NAG stand for?
A
N-acetylglucosamine
21
Q
Is NAM found in all organisms?
A
only bacteria
22
Q
Is NAG found in all organisms?
A
yes
23
Q
How are NAM and NAG attached?
A
covalent bonds
24
Q
What is attached by peptide inter-bridges?
A
NAMs
25
Name three magic bullets
Pennicillin
Cephalosporins
Lysozomes
26
What is a principle component of chiton?
NAG
27
How are NAM molecules connected?
peptide inter bridges
28
How do cephalosporins work?
targets the murien in the cell walls by breaking the peptide inter-bridges which ultimately destroys the cell wall
29
What color is a G+ organism after staining and counter staining?
purple
30
What color is a G- organism after staining and counter staining?
pink
31
What is the most supported theory as to why G+ and G- bacteria are different?
a permeation phenomenon based on the cell wall thickness
32
Do G+ or G- bacteria have teichoic acid?
G+
33
Do G+ or G- bacteria have O-polysaccharied?
G-
34
Do G+ or G- bacteria have lysine?
G+
35
Do G+ or G- bacteria have Diaminopimelic acid?
G-
36
Do G+ or G- bacteria have an outer 2nd membrane?
G-
37
Do G+ or G- bacteria have porins?
G-
38
Do G+ or G- bacteria have more murien in their wall?
G+ has more
39
what percent murein is a G+ cell wall?
50-90%
40
what percent murein is a G- cell wall?
10-20%
41
Do G+ or G- bacteria have a thicker layer of murein in their wall?
G+ has a thicker layer
42
What thickness of murein does a G- bacteria have?
10nm
43
What thickness of its murein layer does G+ have?
20-80nm
44
Do yeast stain G+ or G-?
G+
45
Do fungi have chitin?
yes
46
Do fungi have murein?
no
47
Do all bacteria have an outer membrane?
no, only G- have an outer membrane
48
What is the outer membrane made of?
lipopolysaccharides (LPS)
49
What happens when G- bacteria die?
their outer membrane breaks down into an endotoxin
50
What happens during gram negative shock?
you go into shock, your blood pressure drops and you get a fever
51
Does the outer membrane let everything into the cell?
no, it is selectively permiable
52
What does the outer membrane use to let things through it?
porins
53
What does the outer membrane protect against?
antibiotics
detergents
bile
54
What does bile do?
it emulsifies lipids
55
How does Smith describe the peptidoglycan layer's position in the cell?
"It is between the cell membrane and the outer membrane"
56
Where in the cell is the periplasmic space?
it is between the outer most wall/membrane and the innermost membrane, it may be divided up into pieces if the peptidoglycan layer is present
57
What does the alcohol do to G- bacteria when gram staining?
it poles holes in the outer membrane
58
What is the first living part of the cell?
the cell membrane
59
What is the living part of the cell called?
the protoplast
60
Is the cell membrane impermeable, selectively permeable, or differentially permeable?
differentially permeable
61
What is the protoplast?
the living part of the cell
62
What does differentially permeable mean?
it regulates what is transferred through the cell, not just based on size like selectively permeable
63
Do bacteria have cholesterol in their cell membrane?
no
64
what makes up the bacteria's cell wall?
enzymes
65
What are the purposes of the bacterial cell membrane?
Respiration and regulation
66
What is the chemical make up of a phospholipid?
1 glycerol
2 fatty acids
1 phosphate
1 organic group
67
What is the chemical make up of glycerol?
a 3 carbon alcohol, 3 alcohol groups
68
At what carbon is the phosphate group
it is at the third carbon
69
What is the fluid mosaic model?
the phospholipid molecules and the proteins in the membrane can move
70
what does amphipathic mean?
a molecule which has both hydrophobic and hydrophilic regions
71
Do bacteria have cholesterol or ergosterol?
no
72
In what organisms can you find ergosterol?
fungi
73
In what organisms can you find cholesterol?
animals
74
Is a phospholipid amphipathic?
yes
75
Which part of the phopholipid is hydrophillic?
the phosphate head
76
Which part of the phospholipid is hydrophobic?
the lipid tail
77
What is a sterol?
a steroid linked to an alcohol group
78
Do bacteria have a nucleus?
no
79
Do bacteria have a nucleoid?
yes
80
how many chromosomes do bacteria have?
1
81
What are plasmids?
additional DNA that are sometimes found in bacteria
82
Do bacteria have extrachromosomal DNA?
yes, plasmids
83
Do humans have extrachromosomal DNA?
yes, in our rhibosomes
84
what do plasmids generally code for?
drug resistance
85
What is the organelle of locomotion?
the flagella
86
Does the flagella affect virulence? how so?
yes, it makes it easier for them to invade the body
87
What is the main way that organisms become drug resistant?
plasmids
88
What stain do you use to stain for flagella?
silver stain
89
Describe a bacterial flagella
a single microfillament that rotates to move and is very long
90
Describe a eukaryotic flagella
In eukaryotes fillaments are in a 9+2 arrangement (9 pairs on the outside, 2 in the center of the microtubules)
91
Which are longer flagella or fimbriae?
flagella
92
What is the purpose of fimbriae?
used for attachment to the host cell
93
Name two organisms which have fimbriae?
Nesseria gonorrhea
| e. coli
94
What is opthalmia neonaterum?
newborns are blinded by passing through their mother's gonorrhea infested vagina during birth
95
How are fimbriae and virulence related?
Organisms that lack fimbriae are less pathogenic
96
What is the plural of pulus?
pili
97
What is conjugation?
sharing/exchange of DNA from the nucleoid or the plasmids using a pilus
98
does conjugation lead to genetic recombination?
yes
99
What does the pilus do?
it attaches conjugating bacteria
100
What causes q fever?
coxiella brybati
101
What do endospores do?
they allow for a species to outlive harsh conditions
102
Are endospores a form of reproduction?
no
103
what is the endospore formed in?
it is formed inside the vegetative cell
104
What is the difference between sterilization and disinfection?
Disinfection kills everything but endospores
| Sterilization kills endospores as well as everything else
105
name 4 organisms that form endospores
bacillus
clostridium
sporosarcinae
coxiella brybati
106
what shape is sporosarcinae?
cocci
107
what disease does sporosarcinae cause?
it causes no disease
108
where is coxiella brybati found?
unpasturized milk
109
What diseases have endospores?
anthrax
tetnus
q-fever
110
how many endospores are there formed per cell?
1
