zinc and copper Flashcards

1
Q

zinc is essential in the function of what enzymes

A

carbonic anhydrase
superoxide dismutase
polymerases
kinases
nucleases
transferases
phosphorylases
transcriptases

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2
Q

what is zinc essential for

A

growth
cell division
bone formation
integrity of skin (collagen)
immunity
synthesis of lean tissue
appropriate insulin response

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3
Q

what percentage of zinc is in our body pool

A

60%

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4
Q

how many grams of zinc are in skeletal muscle

A

2g

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5
Q

what percentage of zinc in our body is in bone

A

30%

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6
Q

what percentage of our zinc is in our skin

A

5%

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7
Q

what are sources of zinc

A

Red meat
Seafood (oysters; mussels)
Poultry
Dairy products
Leafy and root vegetables
Wholegrains

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8
Q

whats the EAR for men and women for zinc

A

Males 7.3 mg/d
Females 5.5 mg/d

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9
Q

whats the RNI for men and women of zinc

A

Males 9.5 mg/d
Females 7.0 mg/d

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10
Q

how much of the zinc we consume is absorbed

A

30%

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11
Q

what can a lack of zinc in diet lead to

A

Genetic disorder:
acrodermatitis enteropatica
zinc deficiency

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12
Q

what are symptoms of zinc deficiency

A

Skin lesions (infected; skin; knees; buttocks)

Impaired growth

Poor sexual development

Impaired glucose tolerance

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13
Q

what are some inhibitors of zinc absorption

A

Phytate
Oxalate
Polyphenols
Folate
Iron
Copper
Calcium

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14
Q

explain zincs interaction with vit A

A

metabolism of retinol to retinal (alcohol dehydrogenase) hepatic synthesis of retinol binding protein (Zn deficiency)

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15
Q

what can zinc supplementation lead to

A

copper deficiency (metallothionein)

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16
Q

what is the tolerable upper limit of zinc per day

17
Q

what are the 2 forms of copper

A

(cuprous [Cu1+] and cupric [Cu2+])

18
Q

what is copper required for

A

superoxide dismutase

lysyl oxidase

cytochrome c oxidase (ETC)

amine metabolism (tyramine,histamine, dopamine, 5-HT, polyamines)

Synthesis of noradrenaline from dopamine
19
Q

what is Superoxide dismutase in terms of copper

A

anti-oxidant enzyme removing superoxide radical (O2-) with protons to form O2 and H2O2

20
Q

what is lysyl oxidase in terms of copper

A

crosslinks connective tissue proteins e.g collagen, elastin

21
Q

what is tyrosinase for, in terms of copper

A

Synthesis of melatonin

22
Q

what are some more roles of copper

A

immune system

nerve myelination

angiogenesis

transcription regulation
23
Q

what are some sources of copper

A

Seafood (shellfish; 0.3-4.4 mg/100 g)
Liver (4.5 mg/100 g)
Red meat (0.1 mg/100 g)

Nuts and seeds (1.1-2.2 mg/100 g)
Legumes (0.25 mg/100 g)
Dried fruits (0. 3 mg/100 g)

note: low in milk (premature babies)

24
Q

what is the RNI for copper

25
where is the active carrier mediated for copper absorption
principally in small intestine; more in cuprous (Cu1+) form
26
what percentage of copper is absorbed
50%
27
what enhances copper absorption
some amino acids eg histidine, methionine, cysteine
28
what are inhibitors of copper absorption
phytate, zinc, iron, calcium, phosphorus, ascorbic acid
29
whats menkes disorder cause by in terms of copper
X-linked disorder of transport between intestine and peripheral tissues
30
how is copper transported
Transported in blood attached to ceruloplasmin (liver; ferroxidase I): Also oxidase and anti-oxidant, involved in oxidation of minerals e.g ferrous (Fe2+) to ferric (Fe3+) Also acute phase protein involved in scavenging free radicals of oxygen (inflammation)
31
what are some copper deficiencies
Anaemia (poor mobilisation of iron) Osteoporosis (demineralisation) Low pigmentation (melatonin) Poor immune function Neurological, cardiovascular and respiratory abnormalities