Prokaryotic organisms have
No nuclear envelope
A nuclear envelope
Chromosomes
Which of these are examples of oral habitats for microorganisms?
Buccal mucosa
Dorsal surface of tongue
Appliances
Gingival crevice
Tooth surface
Which of these are non-specific defence factors found in saliva?
Lactoferrin
Lysozyme
IgA
HCO3
PO4
Which of these are specific defence factors found in saliva?
Calcineurin
What are the most important buffer systems of saliva?
HPO4
Na
K
Lysozyme functions by cleaving the -1-4 linkage between N-acetylg and N-acetylm acid which is the repeating saccharide unit of cell wall p. This means it can lyse many streptococci.
What pH of saliva promotes growth of some cariogenic bacteria?
Acidic
Neutral
Alkaline
Which of these are functions of GCF?
Flushing out microbes
Buffering
Provision of defence factors
Phagocytosis of bacteria by T cells
Phagocytosis of bacteria by neutrophils
What is an example of a defence factor in GCF?
Interleukin 1 beta
Interferon alpha
Bacteriocin like inhibitory substrate
Gingipains
What is the predominant leukocyte in GCF?
Neutrophils
B cells
T cells
Macrophages
What is an example of a synergistic interaction of bacteria?
Bacteria using metabolic end products as nutrient sources
The production of BLIS by strep salivarius to inhibit strep pyogenes
Occupation of niches to prevent colonisation by new species
Co-aggregation of the same species of bacteria is known as...
Homotypic
Heterotypic
Transience
Coexistence
What does BLIS stand for?
Bacteriocin like inhibitory substance
Bacterial inhibitory substance
Bacterial lysis substance
What is the main prerequisite for host colonisation?
Adherence to oral surfaces
Failure of host immunity
Previous dental caries
Which of these substances are extracellular polysaccharides produced by certain bacteria?
Glucan
Fructan
Levan
Dextran
What species of bacteria predominates in fissures?
Streptococci
Lactobacilli
Actinomyces
Prevotella, Porphyromonas and Spirochaetes tend to colonise the
Teeth
Strep and Actinomyces spp. tend to attach to the
Dorsum of the tongue
Vestibule
Anaerobic bacteria do not tend to appear until adolescence.
Loss of all the teeth (senility) leads to oral microflora similar to..
Those with appliances
Children before eruption
Adults with acute necrotising ulcerative gingivitis
Those found in the gingival crevice
Denture plaque is most similar to...
Enamel plaque
Crevicular plaque
Mucosal plaque
Dental plaque contains...
Dead bacteria
Living bacteria
Host compounds derived mainly from Saliva
Prions
Metabolic end products of bacteria
Organic matrix makes up ___ of plaque
30%
40%
10%
75%
Plaque is the result of mineralisation of calculus
Glucose is a better intracellular store than glycogen for bacteria.
The enzyme(s) involved in extracellular polysaccharide formation is/are...
Fructosyltransferase
Glucosyltransferase
Hexokinase
Fructokinase
Xylitol is fermented but very slowly
Starch is less cariogenic than sucrose
Cooked starch and sucrose is more cariogenic than sucrose alone
____________________ help bacteria to continue to produce acid after dietary sugar is exhausted
Intracellular polysaccharides
Extracellular polysaccharides
Glucosyltransferase and fructokinase
The most important acid resulting in caries is...
Lactic acid
Acetic acid
Propionic acid
Why can sucrose readily diffuse into plaque?
Small molecular size
Lots of energy released upon its breakdown
Bacterial metabolism is rapid
Label the green question mark
Invertase
Sucrase
Label the red question mark
Maltase
Label the purple question mark
Glycogen
Glucose
Label the blue question mark
Dissolution
Remineralisation
Deposition
Glucosyltransferase can break down sucrose.
Fructosyltransferase can break down sucrose.
Glucosyltransferase converts sucrose into fructans and glucans.
Label the diagram
Irreversible short range interactions of plaque involve
Adhesin receptors
Van Der Waals forces
Hydrogen bonding
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