Biochemistry of Nutrition

Question 1

what is the definition of a vitamin

Answer 1

organic compounds required for normal metabolic function which cannot be synthesised by the body

Question 2

what is the definition of a mineral

Answer 2

inorganic elements which have physiological function

Question 3

which vitamines are fat soluble

Answer 3

EKAD

Question 4

what are the majority of vitamins converted into

Answer 4

coenzymes

Question 5

what is thiamin (B1)converted into

Answer 5

thiamin pyrophosphate (TPP)

Question 6

what enyme is tpp a cofactor for

Answer 6

pyruvate dehydrogenase

a-ketoglutarate dehydrogenase

Question 7

what diseas does thiamin deficiency result in

Answer 7

beri-beri

Question 8

what is riboflavin (B2) a constituent of

Answer 8

FAD and FMN

Question 9

whatcomponent of niacin (B3) a is used as part of NAD(P)H

Answer 9

nicotinic acid

Question 10

what can nicotinic acid be syntheised from in the body

Answer 10

tryptophan

Question 11

what does deficiency in niacin lead to

Answer 11

pellagra

Question 12

what is the funstion of niacin

Answer 12

lowers LDH-C and triglycerides and raises levels of HDL-C

Question 13

what is nicotinamide used at pharmacological doses to treat

Answer 13

skin and neurological disorders

Question 14

what is pantothenic acid used as

Answer 14

a component of coenzyme-A

Question 15

what is biotin used in

Answer 15

prosthetic group for carboxylases acting as CO2 carrier

Question 16

what is biotin deficiency linked wiht

Answer 16

birth defects

Question 17

what enzyme is biotin remade using

Answer 17

biotinidase

Question 18

whatis B6 converted to

Answer 18

PLP

Question 19

what sort of reactions is PLP involved in

Answer 19

transamination and glycogen breakdown
haem synthesis
neurotransmitter synthesis
modulation of steroid hormones actions

Question 20

what can excess PLP cause

Answer 20

nerve damage

Question 21

what metal ion does B12 contain

Answer 21

Cobalt (III)

Question 22

which reactions is B12 involved in

Answer 22

methionine synthase

L-mythylmalonyl-CoA synthase

Question 23

where is B12 found

Answer 23

animal food sources

Question 24

what does deficiency of B12 lead to

Answer 24

pernicious anaemia, eventually macrocytic anaemia and neurlogical symptoms

Question 25

which part of folic acid (B9) is mostly responsible for its activity

Answer 25

pteridine ring

Question 26

what is the main type of reactions is folic acid involved in

Answer 26

one carbon transfers

Question 27

what is folic acid required for biosynthesis of

Answer 27

serine, methionine,glycine,choline,purine nucleotides, dTMP

Question 28

what is the result of deciciency

Answer 28

megaloblastic anaemia and neural tube defects/spina bifida

Question 29

what step of folate recycling is B12 required for

Answer 29

homocysteine + 5-methyltetrahydrofolate--> methionine + tetrahydrofolate

Question 30

what are B12, folate and B6 all required for

Answer 30

DNA methylation

Question 31

what is vit c required for

Answer 31

coenzyme for prolyl hydroxylase and lysyl hydroxylase during collagen synthesis, bile acid synthesis, adrenaline synthesis

Question 32

how is it potentially linked to vit E

Answer 32

required for regeneration of reduced form of vit e

Question 33

what does vit C deficiency lead to

Answer 33

scurvy

Question 34

what is the role of vitamin e

Answer 34

protects from free radicals and lipid peroxidation in membranes

Question 35

what is vit a derived from

Answer 35

b caroteen

Question 36

what does deficiency of vit a lead to

Answer 36

poor vision/blindness death

Question 37

what is vit K required for

Answer 37

coaggulation

Question 38

what are the 2 forms of vit K

Answer 38

phylloquinone and menaquinone

Question 39

what is vit k required for

Answer 39

k dependant carboxylases which convert glutamate to g-carboxyglutamate in clotting factors

Question 40

what is g-carboxyglutamate residues required for in clotting factors

Answer 40

binding calcium

Question 41

what does warfarin do

Answer 41

acts as anticoagulant by preventing regeneration of vit k

Question 42

what is the precursor to vit d synthesis

Answer 42

cholesterol

Question 43

what is required for vit d synthesis

Answer 43

uv light

Question 44

whats the result of lack of vit d

Answer 44

osteomalacia or rickeys

Question 45

what is vit d involved in

Answer 45

``` transcription regulation calcium homeostasis bone growth/maintenance cell proliferation, differentiation and apoptosis immune system skeletal muscle function ```

Question 46

how does vit d effect calcium homestasis

Answer 46

binds receptorsin nucleus increases ca and phosphate absorption from intestine can also mobilise ca from bones if supply insufficient

Question 47

what occurs from lack of iron

Answer 47

anaemia

Question 48

what is iron involved in

Answer 48

electron carrier eg in cytochromes and haem

Question 49

what is the effect of anaemia on rbcs

Answer 49

smaller and paler

Question 50

what is calcium involved in

Answer 50

``` cell signallin neural transmission muscle function blood coagulation secretion biomeneralisation membrane and cytoskeletal functions ```

Question 51

what is the result of deficience of calcium

Answer 51

muscle cramps and spasms | increased risk of osteoperosis

Question 52

how are ca levels controlled

Answer 52

when drop, pth is release promoting release of ca from bone, increase resorption by kidneys and activation of vit D vit d increases absorption from intestines, reguates pth release and increase response of bone to pth