acid responsible for mucth tooth decay; produced by anerobic metabolism
primary bacterium responsible for tooth decay
enzyme that splits sucrose
able to survive in an acidic environment
key polymer in tooth biofilm; alpha-1,6-linked D-glucose polymer with some alpha-1,4 or 3 branches
enzyme that converts sucrose to dextran polymers and free fructose; glycosylhydrolase
fructose polymer made by a S. mutans glycosylhydrolase
alpha-1,3-glucose chains by a S. mutans glycoshydrolase
action of biofilm
sequesters bacterial acid from buffers and keeps acid nect to the tooth enamel
identification of S. mutans as responsible bacteria
trial and error testing of different oral bacteria on germ-free mice
is S. mutans needed for all caries?
no, some can form independent of S. mutans in tooth pits and fissure s
does enamel or dentin have faster carie progression?
dentin, has increased sequestering of hydrogen ion and denaturation of collagen
action of fluoride for carie prevention
fluoride replaces OH on hydroxyapatite in enamel, preventing removal by acid
sugar replacements for diet
xylitol, splenda (sucralose), sorbital
5 carbon aldose with aldehyde group converted to OH
chlorinated anallogue of sucrose
glucose with the aldehyde group replaced with OH. Sugar alcohol
how pronated will a weak acid be when pH is two units lower than the pKa
when will a weak acid be 99% depronated
when the pH is two units greater than the pKa
how is carbonic acid-bicarbonate a good blood buffer despite a pKa of 6.1?
when pH acidified, carbonic acid is produced, it further dissociates into CO2 which is removed by the lungs. This removes some of the hydrogen ion and acidity from the blood.
principle blood buffer systems
bicarbonate and phosphate
importance of pH on local anaesthetics
the active state of the molecule is charged which prevents it from crossing cell membranes, thereby having no effect; the ability of the molecule to lose its charged H+ allows it to become nonpolar and enter the membrane; pH impacts how easily the H+ will leave, depending on the pKa of the molecule
local anaesthetic, pKa = 7.9
local anaesthetic, pKa = 9.0
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