Vitamins

Question 1

which vit can be synthesised by the body

Answer 1

Vit D via sun/UV

B and K from gut bacteria

Question 2

vitamins are

Answer 2

chemically dispartate

Question 3

functions of Vit

Answer 3

co enzymes
hormones
cell signalling
antioxidant
regulators of growth and differentaiton

Question 4

lack of absorption of vitamin may depend on

Answer 4

• reduced absorption can lead to deficiency
• properties of the food
• pre existing disease (impaired fat absorption, low acid in stomach can also affect, B12 cannot be absorpted unless in low acid)
• drugs may compete for absorption, kill bacteria

Question 5

foetus is senstive to

Answer 5

high amounts of Vitamin A

Question 6

Recommended daily allowance

Answer 6

intake that is adequate to ensure all requirements of all healthy people are met

Question 7

fat soluble vitamins

Answer 7

• A
• D
• E
• K

Question 8

water soluble vitamins

Answer 8

B

C

Question 9

which type of vitamins can we store

Answer 9

fat soluble

cannot store water

Question 10

Vitamin A

Answer 10

retinoids (Active form(

carotenoid pigments in plants cleaved to yield retenoids

Question 11

functions of Vitamin A

Answer 11

1. binds to proteins (opsin) in the cells of the retina to form visual pigments
2. nuclear modulator of gene expression
   - lipid souble factor that can pass through cell membrane as it is hydrophobic
   - can then bind to an intracellular receptor
   - then translocated to nucleus
   - associated with an area of the DNA to influence transcription/translation
   Through this mechanism vit a can influence
   - cell proliferation
   - differentiation (especially epithelia)
   - development

Question 12

vit A deficiency

Answer 12

blindness
impaired resistance to infection (lymphocytes and neutrophils affected)
Metaplasia and keratinisation of the conjunctiva epithelial cells

Question 13

Vit D active formes

Answer 13

• Vitamin D3 Calciol/cholecalciferol
• Vitamin D2 ercalciol/ergocalciferol

hormone precusor

Question 14

functions of vit D

Answer 14

• maintenance of plasma calcium concentration (along with parathyroid hormone and calcitonin
• Steroid hormone activating nuclear receptors and influencing over 50 genes

Question 15

bone metabolisms

Answer 15

Vit D stimulated phosphate and calcium absorption in gut
renal absorption of Ca
-osteobalst have receptors for calcitriol
osteoclast activity/num increased
promotes formation and mineralisation of bone

Question 16

vit D deficiency

Answer 16

rickets and osteomalacia
failure of bone mineralisation
impaired immune system

Question 17

vit E

Answer 17

lipid soluble

free radical trapping

Question 18

Vit K

Answer 18

• Coenzyme in posttranslational carboxylation (adding another carboxyl group) of glutamate to Y carboxyl glutamate (gla) (modification of proteins)
• allows it to coordinate with calcium
• allows binding of proteins to membrane phospholipids
• clotting

Question 19

Vit K and clotting

Answer 19

involved in blood coagulation

- thrombin factor 7 and 10 protein C S Z required vitamin K for funciton

Question 20

where does clotting occur

Answer 20

phospholipid surfaces

Question 21

Vit B

Answer 21

allco enzymes
bind to protein/enszymes
requires proteins for biological activity

Question 22

types of Vitamin B

Answer 22

vit B12 and b9
niacin (b3)
riboflavin (b2)
Thiamin B1

Question 23

Thiamin

Answer 23

co enzyme in central energy yielding pathways (pyruvate and kept glutamate
these produce ATP
co enzyme in pentose phosphate pathway (synthesis for nucleotides)

Question 24

what is acetyl Co A used to make

Answer 24

myelin and acetyl choline

neurotransmitters, myelin

Question 25

Riboflavin B2

Answer 25

electron carriers in metabolism reactions (mitochondrial electron transport chain) bound to enzyme

Question 26

niacin b3

Answer 26

precursor of co enzymes NAD and NADP | electron carries in metabolic redox reactions

Question 27

what is niacin b3 synthesised from

Answer 27

dietary trytophan

Question 28

vit B6

Answer 28

pyridoxal phosphate | co factor in transamination reaction in aa metabolisms

Question 29

vit B12 and b9

Answer 29

co enymes | involved in DNA and myelin synthesis

Question 30

vit b12 and 9 defificney

Answer 30

anaemia and neurological damage

Question 31

vit C

Answer 31

reducing sugar and antioxidant

Question 32

role of Fit C

Answer 32

role in enzyme classes - dopamine B hydroxylase: synthesis of adrenaline and noradrenaline (Cu+ dependant, vit keeps copper + not 2+) - Lysine and proline hydrolases: maturation of connective tissue (collagen) Involved in Iron uptake - keeps iron as Fe2+ (not 3+)by chelating it and reducing it which increases absorption

Question 33

vitamins are involved in and relate to dentistry by

Answer 33

wound heeling bleeding resistance to infection bone/tooth Ca2+