Zinc revision - week 12

Question 1

Absorbed

Answer 1

• Better absorbed in small amounts
• 20-33% absorbed
• High amounts of non-heme iron impairs
• Alcohol impairs
• When sborbed – promotes synthesis of metallothionen in enterocytes to bind Zn and keep it there for controlled release

Question 2

Transported

Answer 2

• Bound to proteins in blood e.g. albumin

- Taken to liver and repackaged with other proteins

Question 3

Stored

Answer 3

no main storage site

zinc pool - exchanged between liver, bone, pancreas, kidney and blood

Question 4

Excreted

Answer 4

excess excreted in faeces, some in urine and sweat

Question 5

Food source

Answer 5

seafood e.g. oyster, meat, whole grain

Question 6

deficiency

Answer 6

• Anorexia
• Dermatitis
• Impaired vit A , D and thyroid hormone function

Question 7

toxicity

Answer 7

• Decreased copper absorption
• Diarrhea
• Nausea
• Cramps

Question 8

Main function

Answer 8

• catalytic - cofactor to enzymes (e.g. alcohol metabolism cofactor for alcohol dehydrogenase)
• structural - stability of protein structure (e.g. stabilization of Vit A, D, thyroid hormone receptors and stabilization of protein in bone formation
• regulatory – transcription factor to regulation gene expression (e.g. hormone signally and nerve impulse transmissions)