Bacterial Morphology Flashcards
1
Q
This is the Surface Area to Volume Ratio (SA:V) of a bacterium which allows for easy absorption of food
A
3:1
2
Q
This is the Surface Area to Volume Ratio for eukaryotes
A
0.3:1
3
Q
Which cocci bacteria occur in pairs?
A
diplococci
4
Q
Which cocci bacteria occur in chains?
A
streptococci
5
Q
Which cocci bacteria occur in grape-like clusters?
A
staphylococci
6
Q
pertains to cocci bacteria occur in groups of four
A
tetrad
7
Q
pertains to cocci bacteria occur in groups of eight
A
sarcina
8
Q
These pertains to rod-shaped bacteria
A
bacilli
9
Q
This pertains to chain of bacilli
A
streptobacillus
10
Q
This pertains to very short bacilli so as to appear like cocci
A
coccobacilli
11
Q
This pertains to spindle-shaped rod bacilli
A
Fusiform bacillus
12
Q
This pertains to curved, comma-shaped bacilli
A
vibrio
13
Q
This is a bacteria with a single turn which can also be mistaken for sperm when there is a presence of a tail
A
Vibrio
14
Q
These are bacteria that are spiral in shape and rigid
A
spirillum
15
Q
These are bacteria that are spiral in shape and flexible
A
spirochette
16
Q
What are the other two main components of the cytoplasm of bacteria apart from water?
A
Ribosomes - RNA and proteins
Proteins - mostly enzymes
17
Q
What type of ribosomal monomers do bacteria have? (svedberg)
A
70S
18
Q
The 70S ribosomes of bacteria is composed of which subunits?
A
30S and 50S subunits
19
Q
This component of a bacterial cytoplasm serves as nourishment for the bacterium
A
cytoplasmic or storage granules
-consisting of starch, fat, sulfur or phosphate
20
Q
These are small circular DNA molecules carrying extra genes that make the bacteria more resistant to conventional antibiotics used by doctors
A
plasmids
21
Q
Referred to as the chromosome which contains basic genetic information needed by the cell to survive and produce daughter cells
A
Circular genome
22
Q
These are sac-like invagination of the cytoplasmic membrane containing circular or tubular structures attached to DNA chromatin
A
Mesosomes
23
Q
Mesosomes of bacteria are thought to be associated with which function of the cell?
A
cell division
24
Q
Which aquatic bacteria have a nucleoid surrounded by a two-layer nuclear membrane?
A
Planctomycetes
25
These are intracytoplasmic membrane systems that contain photosynthetic pigments like carotenoids and bacteriochlorophyll
Chromatophores
26
These are non-unit membrane-enclosed structures found in some photosynthetic bacteria
Chlorosomes
27
These are multi-layered structures composed of photosynthetic membranes found in cyanobacteria and used for harvesting light energy
Thylakoids
28
These are cytoplasmic granules produced when source of nitrogen, sulfur, or phosphorus is limited, with excess carbon in the medium
poly-beta-hydroxybutyric acid (PHB)
29
These are granules of polyphosphate produced where there are large reserves of inorganic phosphate
Volutin/ Metachromatic/ Babes-Ernst granules
30
Which bacteria demonstrates clubbing at both ends due to the presence of metachromatic granules?
Corynebacterium diphtheriae
31
Which part of the bacteria contains the electron transport chain cytochromes and other enzymes for oxidative phosphorylation, similar to mitochondrial membrane?
cell membrane
32
This bacterial cell component is a constituent of all bacteria
cell wall
33
This is the internal osmotic pressure of most bacteria that would be sufficient to burst the cell were it not for the presence of a high-tensile strength cell wall
5-20atm
34
This is a biopolymer consisting of sugars and amino acids that provides the strength to the cell wall of bacteria
murein, mucopeptide or peptidoglycan
35
This rigid component determines the shape of the bacterium
cell wall
36
What are the 3 essential parts of the peptidoglycan layer?
1. Backbone - composed of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)
2. A set of identical tetrapeptide side chains
3. A set of identical peptide cross-bridges
37
Which parts of the peptidoglycan layer vary from species to species?
Tetrapeptide side chains and peptide cross-bridges
38
Which molecules is the immediate precursor in the bacterial biosynthesis of lysine and is important in the synthesis of new peptidoglycan?
Diaminopimelic acid
39
The cell wall of gram-positive bacteria is almost exclusively composed of:
peptidoglycan layer
40
This component of the gram-positive cell wall is partially responsible for the negative charge of the cell surface
Teichoic acid (antigenic virulence factor responsible for negative charge)
- Forssmann antigen
- Lipoteichoic acid - virulence factor
- water-soluble, anionic polymers of polyol phosphates (ribitol or glycerol phosphates)
41
Teichoic acid bind which minerals for eventual transport into the cell?
Ca2+ and Mg2+
42
This is the antigenic determinant brought by the teichoic acid component of Gram-positive bacterial cell walls
Forssman antigen
43
The type of teichoic acid covalently bonded to muramic acid residues in cell wall peptidoglycan
Wall teichoic acid (WTA)
44
The type of teichoic acid linked to cytoplasmic membrane that may also be a virulence factor
Lipoteichoic acid (LTA)
45
These are polymers that are like teichoic acid, but the repeat units include sugar acids instead of phosphoric acids.
Teichuronic acids
-synthesized in place of teichoic acids when phosphate is limiting
46
Which type of polysaccharides are usually contained by gram-positive walls?
neutral or acidic
47
What are the three components that lie outside of the peptidoglycan layer of the gram-negative cell wall?
Lipopolysaccharide
Outer membrane
Lipoproteins
48
What are the compositions of the outer leaflet of the outer membrane?
Phospholipids
Porins
Lipopolysaccharides
49
This forms the Outer Membrane Matrix of gram-negative bacteria and contribute to its stabilization
Phospholipids
50
These are protein trimers that form channels, which permit small molecules to diffuse across the membrane
Porins
51
This is the most notable feature of a gram (-) bacterial cell wall
Lipopolysaccharides
52
What type of toxin is the LPS of the outer membrane of gram (-) bacteria?
Endotoxin
53
What are the parts of the LPS of gram-negs?
Lipid A
Polysaccharide core
Repeated unit/ O antigen
54
This is responsible for the toxicity of the LPS and it dictates the disease severity that the gram-neg bacteria can give
Lipid A
55
This confers to the antigenic specificity of the LPS of gram-neg outer membrane
Repeated unit/ O antigen
56
What are the two characteristic sugars of the polysaccharide core of the LPS in gram-negs
Ketodeoxyoctanoid acid (KDO) and a heptose
57
This is the mose abundant protein that compose the inner leaflet of the gram-neg outer membrane
Lipoproteins
?? Broun's lipoprotein ??
58
This anchors the outer membrane to the peptidoglycan layer of gram-neg cell wall, stabilizing it.
Lipoprotein complex
59
This is the space between the inner and outer membrane that contains a gel-like solution of proteins and have enzymes that are responsible for breaking down non-transportable substances to trasportable ones
Periplasmic space
60
Which of the following is present in a gram-positive bacteria?
A. Outer membrane
B. LPS
C. Porin proteins
D. Teichoic acid
E. Periplasm
D. Teichoic acid
**Porin proteins are absent n gram-poss since they are unnecessary due to the absence of outer membrane
61
This is the term used to describe the well-defined mucoid polysaccharide structures that closely surround the cell wall of SOME bacteria.
Capsule
62
This bacterial cell component consisting of sugars (or extracellular polymers) and contributes to the invasiveness of PATHOGENIC BACTERIA since it protects them from phagocytosis
Capsule
63
This is a component of the bacterial cell that is decribed as a long and slender appendage originating from the CYTOPLASMIC MEMBRANE
Flagella
64
This is the protein subunit that makes up the flagella
flagellin
65
What is the antigen of the bacterial flagella?
H antigen
66
Most flagellated pathogens are surrounded by numerous flagella called:
peritrichous
67
Pertains to a bacteria with tuft og flagella at one end
lophotrichous
68
pertains to a bacteria with flagella at both ends
amphitrichous
69
These are mucoid filamentous structures made up of protein that extends from the cell surface; shorter and finer than a flagella
pili
70
What is the structural protein of pili?
pilin
71
The attachment properties of pili is made possible by which minor protein located at their tips?
adhesins
72
This is a class of pili that is hollow and found at random sites in the bacteria, functioning for the attachment of donor and recipient cells and exchange of genetic materials or bacterial conjugation
sex pili
73
This class of pili is more numerous and evenly distributed on the surface of the bacteria, enabling it to stick to surfaces (virulence factor)
Common or Fimbriae
74
This specific component of a bacteria functions for adherence of symbiotic and pathogenic bacteria to host cells and may undergo antigenic variation to evade host immune system
Common or Fimbrae Pili
75
2 most common gram-positive rods that produce endospores:
Aerobic genus Bacillus
Anaerobic genus Clostridium
76
Sporulation results from changes that represent a true process of _________, a series of genes whose products determine the formulation of final composition of the spores
differentiation
77
During sporulation, there are changes in the transcriptional specificity of the RNA polymerase. This is determined by the association of the polymerase core protein with one or another promoter-specific protein called:
sigma factors
78
During vegetative growth of bacteria, the sigma factor that predominates is designated as:
σᴬ
79
The energy-generating system of endospores is ________, occurring in the spore protoplast or core
glycolysis
80
True or False:
In endospores, cytochromes are lacking even in aerobic species.
True
-spores of which rely on shortened electron transport pathway involving flavoproteins
81
The energy of germination of spores is stored as _______ rather than ATP
3-phosphoglycerate
- spores contain no reduced pyridine nucleotides or ATP
82
The heat resistance of spores is partly attributable to their dehydrated state and in part to the presence in the core of substantial amounts of:
Calcium dipicolinate
- confers heat resistance to the spore
83
Calcium dipicolinate of spores is formed from an intermediate of the _________ biosynthetic pathway
lysine
84
This is the thickest layer of the spore enveloped
cortex
85
What is the part of the spore that contains normal peptidoglycan and becomes the cell wall of the germinating vegetative cell?
spore wall
- the innermost layer surrounding the inner spore membrane
86
Since this part of the pore is extremely sensitive to lysozymes, its autolysis plays a role in the spore germination
cortex peptidoglycan
87
This part of the spore is composed of a keratin-like protein containing many intramolecular disulfide bonds, and the IMPERMEABILITY of this layer confers on spores their relative resistance to antibacterial chemical agents
coat
88
What are the 3 stages of spore germination?
Activation
Initiation
Outgrowth
89
The following are some agents that can overcome spore dormancy, except:
A. Heat
B. Abrasion
C. Alkalinity
D. Free sulfhydryl groups from certain compounds
D. should be acidity
90
After activation of spores, initiation is triggered by binding of effector which then activates an _______ that rapidly degrades the cortex peptidoglycan
autolysin
91
The period of active biosynthesis of spores terminating in cell division is called:
Outgrowth
-requires a supply of all nutrients essential for cell growth
