Microbial Cell Structure and Function Flashcards
1
Q
pneumonic device for Gram-negative and Gram-positive bacteria & their structure:
A
LONG PPT
2
Q
what does LONG PPT stand for?
A
Lipopolysaccharide
Outer membrane
Negative
Gram?
Positive
Peptidoglycan (thick)
Teichoic acid
3
Q
Common bacterial structures (11):
A
- plasma membrane
- gas vacuole
- ribosomes
- inclusions
- nucleoid
- periplasmic space
- cell wall
- capsules + slime layers
- fimbriae + pili
- flagella
- endospore
4
Q
type of common bacterial structure: selectively permeable barrier, mechanical boundary of cell, nutrient and waste transport, location of many metabolic processes (respiration, photosynthesis), detection of environmental cues for chemotaxis
A
plasma membrane
5
Q
type of common bacterial structure: an inclusion that provides buoyancy for floating in aquatic environments
A
gas vacuole
6
Q
type of common bacterial structure: protein synthesis
A
ribosomes
7
Q
type of common bacterial structure: storage of carbon, phosphate, and other substances
A
inclusions
8
Q
type of common bacterial structure: localization of genetic material (DNA)
A
nucleoid
9
Q
type of common bacterial structure: in typical Gram-negative bacteria, contains hydrolytic enzymes and binding proteins for nutrient processing and uptake; in typical Gram-positive bacteria, may be smaller or absent
A
periplasmic space
10
Q
type of common bacterial structure: protection from osmotic stress, helps maintain cell shape
A
cell wall
11
Q
type of common bacterial structure: resistance to phagocytosis, adherence to surfaces
A
capsuoles and slime layers
12
Q
type of common bacterial structure: attachment to surfaces, bacterial conjugation and transformation, twitching and gliding motility
A
fimbriae and pili
13
Q
type of common bacterial structure: swimming ang swarming motility
A
flagella
14
Q
type of common bacterial structure: survival under harsh environmental conditions
A
endospore
15
Q
T/F: all bacteria has all of the common bacterial strucutres at one time
A
false
16
Q
archaea are very similar to bacteria and their structures — the only unique bacteria HAVE that archaea dont is what?
A
capsules + slime layers
17
Q
the cytoplasm is full of ______
A
proteins
18
Q
inclusions look like _____
A
popcorn
19
Q
T/F: inclusions are organelles
A
false!
20
Q
hairs; attaches to surface
A
fimbriae
21
Q
thin structure that separates cytoplasm from the environment
A
cytoplasmic membrane (or plasma or cell membrane)
22
Q
functions of the cell membrane (3):
A
1) permeablility barrier (includes secretion, excretion, and translocation)
2) protein anchor
3) energy conservations
23
Q
function of cell membrane: prevents leakage and functions as a gateway for transport of nutrients into, and wastes out of, the cell
A
permeability barrier
24
Q
function of cell membrane: site of proteins that participate in transport, bioenergetics, and chemotaxis — aka transport, energy, and signals
A
protein anchor
25
function of cell membrane: site of generation and dissipation of the proton motive force; can be used to make ATP through ATP-synthase; separateps charge
energy conservation
26
the cell membrane separates charges, where _____ charges are on the inside and ______ are on the outside
negative; postive
27
the separation of charge by the cell membrane is a form of ____ _____
potential energy
28
permeability barrier of cell membrane: make something insdie (ex: toxin) and release it to the environment with a purpose
secretion
29
permeability barrier of cell membrane: getting rid of waste
excretion
30
permeability barrier of cell membrane: moving things from one part of the cell to another
translocation
31
bacteria do NOT use _____ or ________; everything has to go in/out via the cell membrane
endocytosis or exocytosis
32
most mitochondria use membranes like ______ do
bacteria
33
cell membrane can add structural ________
stability
34
most bacteria DONT use _______
sterols
35
what is the cytoplasmic membrane made out of?
lipid bilayer composed of phospholipids
36
the cell membrane is termed "_______;" means its both polar and non-polar
amphipathic
37
polar ends are _______
hydrophilic
38
non-polar tails are ______
hydrophobic
39
_______ levels of the cell membrane reflect the environment
saturation
40
membranes with ________ fatty acids are much more common in HOT temperatures
saturated
41
membranes with ________ fatty acids are much more common in COLD termperatures
unsaturated
42
which is more flexible? membranes with saturated or unsaturated fatty acid components?
unsaturated!
43
some bacteria have _____ within their lipid bilayer, which adds STRUCTURAL STABLILITY
hopanoids
44
what types of bacteris have hopanoids (2):
- cyanobacteria
- bacteria in warmer environments
45
the head groups of the lipid bilayer are _______ and ______
hydrophilic (water loving) + polar
46
the fatty acid tails of the lipid bilayer are _______ and ______
hydrophobic (water-hating) + nonpolar
47
unsaturated fats have _____ double bonds
2
48
T/F: all proteins within the cytoplasmic membrane are involved in some sort of transport
false
49
membrane protein: embedded within the membrane (AMPHIPATHIC - may or may not go all the way through the membrane); comprise 70-80% of the membrane proteins; carry out important function (transport, secretion, energy conservation)
integral membrane proteins
50
membrane protein: proteins only on one side of the plasma membrane; loosely connected to membrane; comprise 20 to 30% of the membrane proteins
peripheral protein
51
integral proteins comprise ____-____% of the membrane proteins
70 - 80%
52
peripheral proteins comprise ____-____% of the membrane proteins
20 - 30%
53
The bacterial cytoplasmic membrane is all of these EXCEPT:
a) selectively permeable phospholipid bilayer
b) amphipathic
c) a possible site for ATP production
d) used for endocytosis
e) structurally weak in most bacteria
d) used for endocytosis
54
important functions of INTEGRAL proteins (3):
- transport
- secretion and excretion
- energy conservation
55
rigid structure that lies outside the plasma membrane; can contain peptidoglycan (only in bacteria)
cell wall
56
peptidoglycan is only found in the cell wall of what domain of microorganisms?
BACTERIA
57
_____ _______ is created in bacterial cells due to the rigidness of the cell wall
turgid pressure
58
functions of the cell wall (4 - in both gram+ and gram-)
1) provides shape to cell
2) protects from osmotic lysis
3) may contribute to pathogenenicity
4) protects from toxic substances
59
when too much water comes into the cell and bursts the cell wall
osmotic lysis
60
cell walls can be _______ -- helps it to attach from tissue and prevent toxins from coming in
inflammatory
61
in Gram-positive cells, ____% of the cell wall is peptidoglycan; "peptidoglycan sack"
90%
62
Gram-positive or Gram-negative? : TINY periplasmic space; some argue its not even there
Gram-positive
63
Gram-positive or Gram-negative? : periplasmic space is FULL of enzymes
Gram- negative
64
the outer membrane in Gram-negative bacteria helps with _______
stability
65
important component of BOTH gram-postive and gram-negative bacteria; made of sugars and amino-acids; unique for domain bacteria
peptidoglycan
66
peptidoglycan is a ______ polymer
meshlike
67
two _____ ______ form the backbone of peptidoglycan
alternating sugars
68
2 alternating sugars that form the backbone of peptidoglycan =
- N-acetylglucosamine (NAG)
- N-acetylmuramic acid (NAM)
69
NAG =
N-acetylglucosamine
70
NAM =
N-acetylmuramic acid
71
along with alternating sugars, the meshlike polymer of peptidoglycan is also made of alternating ____ and ____ ______ _______
D- and L- amino acids
72
____ _____ occurs with amino acids in peptidoglycan
cross-linking
73
does diversity within peptidoglycan come from the alternating sugars or alternating amino acids?
amino acids
74
NAG and NAM are always linked where?
beta (1,4) glycotic bond
75
NAM is linked to a ________; can break
lysozyme
76
found in saliva, tears, and sweat; can kill bacteria
lysozyme
77
amino acids ALWAYS hang off the ______ in peptidoglycan
NAM
78
how many amino acids come off of NAM?
4
79
a lot of antibiotics target the ____ _____
cell wall
80
prevents peptides from linking up; transpeptidation; affects gram-POSTIVE
penicillin
81
in E. coli, there is a ______ linkage between peptides
direct
82
in S. aureus, there is a ______ linkage between peptides
indirect (has an interbridge between them)
83
in S. aureus, there is an _______ between peptides
interbridge
84
what is the interbridge in S. aureus composed of?
5 glycines
85
gram-positive cell walls are composed primarily of _______ (up to 90% of wall / 15 layers)
peptidoglycan
86
gram-positive cell walls may also contain ________ acids (neg. charged)
teichoic acids
87
teichoic acids are ______ charged
negatively charged
88
functions of teichoic acids in Gram+ cell walls (4):
1) bind Ca+ and Mg2+
2) help maintain strucutre of the cell wall (covalently bonded)
3) protect from harmful substances
4) role in pathogensis
89
glycerol/ribital phosphates; poly-alcohols; ONLY in Gram(+) and gives it a NEG. charge
teichoic acids
90
teichoic acids attached to membrane lipids
lipoteiochoic acids
91
some Gram(+) bacteria have a layer of _____ on the surface of peptidoglycan -- helps with interactions with the ENVIRONMENT
proteins
92
the cell wall is a lot less ______ compared to the membrane but still filters through
selective (termed "sive")
93
negatively charged acids on gram(+) bacteria); do NOT go all the way through the cell wall
teiochoic acid
94
negatively charged acids on gram(+) bacteria); do go ALL the way through the cell wall
lipoteiochoic acids
95
along with teichoic and lipoteichoic acids in the cell wall, gram(+) cell walls also have _____ ______ ______
wall-associated proteins
96
detect nutrients, motility, etc. in the cell wall of gram(+) bacteria
wall-associated protein
97
consist of a thin layer of peptidoglycan surrounded by an outer membrane
gram-negative cell wall
98
gram-negative outer membranes are composed of what 3 things?
- lipids
- lipoproteins
- lipopolysaccharide (LPS)
99
T/F: gram-negative bacteria have teoichoic acids in their cell wall
false
100
another lipid bilayer; more porous; a lot of lipids are replaced with this, so much that some call the outermembrane the ____ layer; only in gram-negative bacteria
LPS (lipopolysacchardides)
101
how many layers of peptidoglycan are in gram-negative cells?
1-3 layers
102
components of gram-negative cell walls (4):
- peptidoglycan
- periplasm
- outer membrane
- Braun's lipoproteins
103
component of gram-negative cell wall: up to 10% of the cell wall
peptidoglycan
104
component of gram-negative cell wall: HUGE; may consitute 20-40% of cell volume
periplasm
105
the periplasm of gram-negative cell walls may constitute ____-____% of the cell's volume
20-40%
106
there are many _____ present in the periplasm in gram(-) bacteria
enzymes
107
what kind of enzymes are present in the periplasm within gram(-) bacteria (3)?
- hydrolytic enzymes
- binding proteins
- chemoreceptors
108
component of gram-negative cell wall: lies outside the thin peptidoglycan layer; includes PORINS
outer membrane
109
channels through qhich small, hydrophilic molecules (like sugars) can pass; 3 tubes stuck together; lined with water; all HYDROPHILIC substancces, neutral, and small substances pass
porins
110
waht kind of substances can pass through porins in gram(-)'s outer membrane (3)?
- HYDROPHILIC substancces
- neutral
- small substances pass
111
component of gram-negative cell wall: connect outer membrane to peptidoglycan; ANCHORS
Braun's lipoproteins
112
3 parts of LPS (lipopolysaccharide):
1) lipid A
2) core polysaccharide
3) O-specific polysaccharide
113
lipid A is termed an _______
endotoxin
114
part of LPS: varies depending on species; usually the same for the same species
core polysaccharide
115
different names for O-specific polysaccharide (2):
- O antigen (stimulate immune responses)
- O-side chain
116
part of LPS: varies based on the STRAIN
O-specific polysaccharide
117
why is the O-specific polysaccharide sometimes called the "O-antigen"?
it can stimulate immune responses
118
in LPS, the _____ _______ and ____ _____ ____ extend OUT from the cell
core polysaccharide + O side chain
119
severity of salmonella is due to what part of LPS?
lipid A (endotoxin)
120
importance/part of LPS: contributes NEGATIVE charge on cell surface =
core polysaccharide
121
importance/part of LPS: helps stablize outer membrane structure; replaces phospholipids =
lipid A
122
importance of LPS: may contribute to attachment to surfaces and ______ formation; uses sugars sticking out helps attach bacteria to other bacteria
biofilm
123
groups of bacteria sticking together
biofilm
124
importance of LPS: creates a ________ barrier
permeability
125
importance/part of LPS: may mutate to protect from host defenses =
O-antigen
126
why is it good for the O antigen of LPS to be able to mutate easily?
immune systems arent able to recognize them; protects them from host defenses
127
importance/part of LPS: acts as an "endotoxin" --- AKA POISON
lipid A
128
a toxin inside out body that colonizes
endotoxin
129
If you only had access to the cell wall of a bacterium, how would you determine if it was gram(+) or gram(-)?
look for presence/absence of teichoic acids AND LPS
130
components of Osmotic Protection (2):
- hypotonic environments
- hypertonic environments
131
component of Osmotic Protection: solute OUTSIDE the cell > solute INSIDE the cell
hypotonic
132
component of Osmotic Protection: solute INSIDE the cell > solute OUTSIDE the cell
hypertonic
133
component of Osmotic Protection: water moves INTO the cell and cell swells; cell wall protects from lysis
hypotonic environment
134
component of Osmotic Protection: water LEAVES the cell; plasmolysis occurs
hypertonic environment
135
where do bacteria want to be --- hypo or hypertponic environments?
hypotonic
136
if the cell wall is compromised, the cell could _____ if it is in a hypotonic environment
lyse
137
process of a cell shriveling up in a hypertonic environment
plasmolysis
138
T/F: fungi can withstand hypertonic environments better than bacteria mostly
T (ex: jelly)
139
evidence of protective nature of cell wall: breaks the bond between NAG and NAM
lysozyme
140
what bond does lysozyme break the bond between NAG and NAM?
Beta (1,4)
141
evidence of protective nature of cell wall: _______ inhibits peptidoglycan synthesis; messes up peptide bonds between layers
penicillin
142
if cells are treated with _____ or _____, they will lyse if they are put in a HYPOTONIC solution
lysozyme or penicillin
143
what organisms do NOT have a cell wall and can survive in isotonic environments (2)?
- protoplasts
- spheroplasts
144
survive in isotonic environments; Gram-POSITIVE cell with its wall removed
protoplasts
145
survive in isotonic environments; Gram-NEGATIVE cell with its wall removed
spheroplasts
146
no cell wall; plasma membrane more resistant to osmotic pressure; some are pathogenic; SMALLEST BACTERIA; have sterols
Mycoplasma
147
what is typically rare for prokaryotes, used to stablize the cell membrane, and MYCOPLAMSA have them ?
sterols
148
example of a sterol
cholesterol
