biochem 7B mineralization

Question 1

what area of the tooth does not demonstrate mienralization

Answer 1

pulp

Question 2

what are the hardest tissues of the tooth

Answer 2

enamel and dentin

Question 3

hardness in biologyical systems is related to what

Answer 3

the ability to form calcium salts

Question 4

mineral in the teeth is what and what is the formula

Answer 4

hydroxyapatite
Ca10(PO4)6(OH2)
it is a dimer

Question 5

dentin breakdown

Answer 5

70% mineral, 30% protein

Question 6

enamel breakdown

Answer 6

97% mineral, less than 1% protein

Question 7

enamel is formed on extracellular matrix involving what organizing proteins by what

Answer 7

organizing proteins - enamelins and amelogenins
by ameloblasts

Question 8

what are ameloblasts

Answer 8

cells which secrete the enamel protein enamelin and amelogenin which will later mineralize to form enamel on teeth, the hardest substance in the human body

Question 9

when are ameloblasts present

Answer 9

only during tooth development

Question 10

where is dentin formed and how is it form

Answer 10

formed by odontoblasts
formed around the pulp on an extracellular matrix of collagen and non-collagenous proteins

Question 11

what are apatities

Answer 11

phosphorylated minerals that typically contain calcium

Question 12

what is the most common apatite

Answer 12

hydroxyapatite Ca10(PO4)OH2

Question 13

when OH is replaced by fluoride in hydroxyapatite what does it become

Answer 13

fluoroapatite
Ca10(PO4)6(F2)

Question 14

calcium phosphates (hydroxyapatite) is very insoluable or soluable

Answer 14

highly insoluable

Question 15

what is nucleation and when does it occur

Answer 15

nucleation - when theres the right environemnt (includes scaffolding proteins) and right factors (high concentration of ions) mineral will form

Question 16

what mineralizes dentin and what scaffolding protein does it need

Answer 16

odontoblasts, collagen

Question 17

what minearlizes enamel and what scaffolding proteins does it need

Answer 17

ameloblasts, amelogenins

Question 18

what is exuded by odontoblasts which line the pulp cavity purgest the enaml of bacterial waste

Answer 18

dentinal fluid

Question 19

primary function of dental pulp is what

Answer 19

to form dentin (by the odontoblasts)

Question 20

saliva is supersaturated with what ions and buffers around what pH

Answer 20

calcium and phosphate ions, around pH7

Question 21

what are the bacterial waste products

Answer 21

-bacteria metabolizing aerobically excude CO2 and H2O
-bacteria metabolizing anaerobically excude acids (lactic acid)

Question 22

enamel beings to dissolve and dimineralize at what pH

Answer 22

5.5

Question 23

what in the saliva helps resist the loss of mienral

Answer 23

calcium and phosphate

Question 24

what helps neutralize acid and wash out waste

Answer 24

fluid flowing from the pulp

Question 25

what stabilizes crystallites

Answer 25

anionic proline-rich proteins and statherin

Question 26

what does aniomic proline rich proteins do

Answer 26

bind to calcium

Question 27

what does statherin do

Answer 27

maintains high calcium level in saliva, which prevents teeth from dissolving

Question 28

what does saliva do to pH

Answer 28

neutralizes H+

Question 29

adding fluoride forms what

Answer 29

fluorapatite

Question 30

fluorapatite is insoluable or soluable and how does it compare to fluorapatite

Answer 30

insoluable
fluorapatite is severla times less soluable

Question 31

is fluorapatite more or less resistant to demineralization by acid than hydroxypatite

Answer 31

more resistant to demineralization by acid

Question 32

how does fluoride help

Answer 32

inhibit bacterial metabolism lowering acid excretion by plaque bacteria

Question 33

what amound of fluoride in water is optimal for cavity protection

Answer 33

1 ppm

Question 34

greater the floride, greater the index of what

Answer 34

fluorosis (white or brown specs on ur teeth)
8-10ppm

Question 35

is fluoroapatite more resistant or less resistant to demineralization by acid than hydroxapatite

Answer 35

more resistant

Question 36

what happens in fluoride poisoning

Answer 36

associated w lack of energy due to its inhibiting enolase and therefore glycolysis

Question 37

if flouride is taken at high levels to control osteoporosis, what is the result and does it inhibit osteoblast or osteoclast more

Answer 37

inhibits osteoblast activity more than osteoclast activity, resulting in an increased frequency of bone fractures

Question 38

flouride inhibits what at 50-100ppm and how

Answer 38

inhibits gluconeogenesis by binding to Mg2+ ions that activity fructose 1,6 diphosphate
inhibits ROS elimination by binding iron, selenium and molybdenum at catalytic centers of catalase, peroxidase, and superoxide dismutase