747894
Beschreibung
Mindmap von bsmith.1994, aktualisiert more than 1 year ago
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Erstellt von bsmith.1994
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Biochemistry
of Nutrition
- 1.5 billion people in the
world obese, meanwhile
925 million underweight
- Vitamins
- Organic compounds
not synthesised in
the body
- required in ug/mg
- deficiency causes disease,
which are treated by restoring
levels through ingestion
- can be water
or fat soluble
- B vitamins and vitamin C
water soluble
- Vitamins E, K, A, D
all fat soluble
- B vitamins and vitamin C
water soluble
- B Vitamins
- Thiamin (B1)
- Converted to thiamin
pyrophosphate (TPP)
- TPP is a vital cofactor used by
pyruvate dehydrogenase
- other enzymes involving
oxidative decarboxylation also
use TPP, such as
a-ketoglutarate dehydrogenase
- TPP is a vital cofactor used by
pyruvate dehydrogenase
- thiamin deficiency
causes beri-beri
- symptoms include muscle
weakness from nerve damage
- symptoms include muscle
weakness from nerve damage
- Converted to thiamin
pyrophosphate (TPP)
- Riboflavin (B2)
- constituent of flavin
coenzymes (FAD/FMN)
- constituent of flavin
coenzymes (FAD/FMN)
- Niacin (B3)
- nicotinamide/nicotinic acid
components of NAD(P)H
- nicotinic acid
lowers LDL-C and
raises HDL-C
- nicotinamide is used
to treat skin and
neurological disorders
- prolonged high
dosage of either can
result in liver damage
- nicotinic acid
lowers LDL-C and
raises HDL-C
- can be synthesised
in the body from
tryptophan
- deficiency causes
pellagra
- symptoms include:
sunburn-like rash,
diarrhoea,
depressive
psychosis,
eventual death
- symptoms include:
sunburn-like rash,
diarrhoea,
depressive
psychosis,
eventual death
- nicotinamide/nicotinic acid
components of NAD(P)H
- Pantothenic acid (B5)
- component of Coenzyme A
- component of Coenzyme A
- Biotin (B7)
- used in either metabolism or
transcription as part of the biotin cycle
- prosthetic group for
carboxylases
- histone proteins in
nuclesomes
- biocytin (biotin covalently bonded to a
lysine) released during protein turnover,
converted back to biotin via biotinidase
- prosthetic group for
carboxylases
- used in either metabolism or
transcription as part of the biotin cycle
- Vitamin B6
(Pyridoxine)
- required in many parts
of metabolism
- converted to
pyridoxal-5'-phosphate (PLP),
which is required for over 100
enzyme functions
- transamination
- glycogen breakdown
- haem synthesis
- neurotransmitter
synthesis
- serotonin
- dopamine
- noradrenalin
- GABA
- serotonin
- modulates action of
steroid hormones
- oestrogen
- testosterone
- oestrogen
- transamination
- required in many parts
of metabolism
- Vitamin B12
- large complex with
cobalt (III) ion
- crucial for 2 enzymes
Anmerkungen:
- methionine synthase L-methylmalonyl-CoA mutase
- found only in
animal sources
- bound in stomach to R-binding
protein, which is degraded as
B12 reaches the duodenum, so
it can be absorbed in the small
intestine via intrinsic factor
- problems with this pathway lead to
macrocytic anaemia and
neurological problems
- problems with this pathway lead to
macrocytic anaemia and
neurological problems
- needed for the recycling of folate
- all linked in pathways
for DNA methylation
- large complex with
cobalt (III) ion
- Folic acid (B9)
- key to 1 carbon
transfers
- tetrahydrofolate is main
molecule involved in this
process
- key to biosynthesis of several
molecules, inlcluding dTMP, that
regenerates folate
Anmerkungen:
- other include serine, methionine, glycine, choline and purine nucleotides
- during this process, THF donates a
methylene and is oxidised to DHF,
dihydrofolate reductase is required to
reduce it back to THF, any absence of
this inhibits DNA synthesis so is a target
for cancer therapy
Anmerkungen:
- methotrexate aminopterin trimethoprim
- tetrahydrofolate is main
molecule involved in this
process
- deficiency leads to
megaloblastic anaemia
and neural tube defects
(spinal bifida)
- key to 1 carbon
transfers
- water soluble
- Thiamin (B1)
- Vitamin C
(ascorbic acid)
- large role in collagen synthesis,
coenzyme for prolyl hydroxylase and
lysyl hydroxylase
- prolyl hydroxylase involved in
hydroxyproline synthesis, which
stabilises the collagen triple helix
- lysyl hydroxylase involved in
hydroxylysine synthesis, which aids
cross-linking between chains
- prolyl hydroxylase involved in
hydroxyproline synthesis, which
stabilises the collagen triple helix
- deficiency leads to scurvy,
which results in weak collagen
- symptoms include
fatigue, joint pain,
muscle weakness,
haemhorrhages,
gum disease
- symptoms include
fatigue, joint pain,
muscle weakness,
haemhorrhages,
gum disease
- excess vitamin C
consumption can
cause kidney stones
- large role in collagen synthesis,
coenzyme for prolyl hydroxylase and
lysyl hydroxylase
- Vitamin E
(a-Tocopherol)
- protect from free
radicals - antioxidant
- protect from lipid
peroxidation in membranes
- fat soluble
- protect from free
radicals - antioxidant
- Vitamin A
- derived from dietary
B-carotene
- B-carotene dioxygenase in
intestines cleaves to form
retinal
- retinaldehyde reductase forms
retinol using NADPH
- esterified to palmitic acid
- in to chylomicrons, which
transport it to liver, retinol is
taken up in the liver by RBP
- in to chylomicrons, which
transport it to liver, retinol is
taken up in the liver by RBP
- esterified to palmitic acid
- retinaldehyde reductase forms
retinol using NADPH
- retinol condenses with
a lysine on opsin in rod
cells to form rhodopsin
- deficiency leads to
poor vision then
blindness
- derived from dietary
B-carotene
- Vitamin K
- phylloquinone in plants
- menaquinone in
intestinal bacteria
- coenzyme for carboxylases, forming
y-carboxyglutamate from glutamate
- factors requiring vitamin K
involved in coagulation
- Warfarin is an anticoagulant
that prevents regeneration of
active vitamin K
- phylloquinone in plants
- Vitamin D
- cholesterol is a precursor for
vitamin D synthesis
- 7-dehydrocholesterol is converted
to cholecalciferol (D3) on the skin
through the action of UV radiation
- cholecalciferol is converted
to 25-hydroxyvitamin D3
(calcidiol) in the liver
- calcidiol is converted to 1,
25-dihydroxyvitamin D3
(calcitriol) in the kidney, this is
the biologically active form
- circulates as a
hormone in the blood
- regulates
calcium/phosphate in
bloodstream
- circulates as a
hormone in the blood
- calcidiol is converted to 1,
25-dihydroxyvitamin D3
(calcitriol) in the kidney, this is
the biologically active form
- cholecalciferol is converted
to 25-hydroxyvitamin D3
(calcidiol) in the liver
- deficiency causes bone
disease (osteomalacia/rickets)
- also linked to cancer risk
- also linked to cancer risk
- cholesterol is a precursor for
vitamin D synthesis
- Organic compounds
not synthesised in
the body
- Minerals
- inorganic elements with
physiological function
- required in
varying amounts
- ug of 'trace'
elements
- g of Na/Ca/K/P
- ug of 'trace'
elements
- Iron
- found in haem proteins
and electron carriers
(cytochrome)
- deficiency leads to anaemia
- binds to oxygen
- found in haem proteins
and electron carriers
(cytochrome)
- Calcium
- involved in several processes
- cell signalling
- neural transmission
- muscle function
- membrane/cytoskeletal function
- blood coagulation
- cell signalling
- hypocalcaemia leads to
muscle cramps/spasms
- calcium levels controlled
by parathyroid hormone
- involved in several processes
- Iodine
- vital for thyroid hormones function
- inadequate iodine during
pregnancy affects cognitive
development of foetus
- vital for thyroid hormones function
- Cobalt in nitrile hydratase
- Copper in oxidoreductases
- Zinc in proteases
- Selenium in glutathione peroxidase
- inorganic elements with
physiological function
Medienanhänge
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