zinc and copper Flashcards
zinc is essential in the function of what enzymes
carbonic anhydrase
superoxide dismutase
polymerases
kinases
nucleases
transferases
phosphorylases
transcriptases
what is zinc essential for
growth
cell division
bone formation
integrity of skin (collagen)
immunity
synthesis of lean tissue
appropriate insulin response
what percentage of zinc is in our body pool
60%
how many grams of zinc are in skeletal muscle
2g
what percentage of zinc in our body is in bone
30%
what percentage of our zinc is in our skin
5%
what are sources of zinc
Red meat
Seafood (oysters; mussels)
Poultry
Dairy products
Leafy and root vegetables
Wholegrains
whats the EAR for men and women for zinc
Males 7.3 mg/d
Females 5.5 mg/d
whats the RNI for men and women of zinc
Males 9.5 mg/d
Females 7.0 mg/d
how much of the zinc we consume is absorbed
30%
what can a lack of zinc in diet lead to
Genetic disorder:
acrodermatitis enteropatica
zinc deficiency
what are symptoms of zinc deficiency
Skin lesions (infected; skin; knees; buttocks)
Impaired growth
Poor sexual development
Impaired glucose tolerance
what are some inhibitors of zinc absorption
Phytate
Oxalate
Polyphenols
Folate
Iron
Copper
Calcium
explain zincs interaction with vit A
metabolism of retinol to retinal (alcohol dehydrogenase) hepatic synthesis of retinol binding protein (Zn deficiency)
what can zinc supplementation lead to
copper deficiency (metallothionein)
what is the tolerable upper limit of zinc per day
40 mg/d
what are the 2 forms of copper
(cuprous [Cu1+] and cupric [Cu2+])
what is copper required for
superoxide dismutase
lysyl oxidase cytochrome c oxidase (ETC) amine metabolism (tyramine,histamine, dopamine, 5-HT, polyamines) Synthesis of noradrenaline from dopamine
what is Superoxide dismutase in terms of copper
anti-oxidant enzyme removing superoxide radical (O2-) with protons to form O2 and H2O2
what is lysyl oxidase in terms of copper
crosslinks connective tissue proteins e.g collagen, elastin
what is tyrosinase for, in terms of copper
Synthesis of melatonin
what are some more roles of copper
immune system
nerve myelination angiogenesis transcription regulation
what are some sources of copper
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)
what is the RNI for copper
1.2 mg/d
where is the active carrier mediated for copper absorption
principally in small intestine; more in cuprous (Cu1+) form
what percentage of copper is absorbed
50%
what enhances copper absorption
some amino acids
eg histidine, methionine, cysteine
what are inhibitors of copper absorption
phytate, zinc, iron, calcium, phosphorus, ascorbic acid
whats menkes disorder cause by in terms of copper
X-linked disorder of transport between intestine and peripheral tissues
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)
what are some copper deficiencies
Anaemia (poor mobilisation of iron)
Osteoporosis (demineralisation)
Low pigmentation (melatonin)
Poor immune function
Neurological, cardiovascular and respiratory abnormalities
