Minerals Flashcards
What are the dietary requirements for iron (Fe), copper (Cu) and zinc (Zn)?
Adults:
Fe = 18mg
Cu = 2mg
Zn = 15mg
What is a trace element?
Essential nutrient only required in very small amounts compared to vitmains and minerals.
Name 3 trace elements.
Cobalt - in cobalamin
Molybdenum - in co-factor
Manganese - needed for metabolism
What is the body’s daily need for cobalt and why is it important?
Present in cobalamin (B12)
Important for metabolism of odd chain fatty acids.
Total in body = 1mg
Requirement = 2micrograms/day
What is the body’s daily need for molybdenum and its importance?
Present in co-factor.
Only needed for 4 enzymes in body.
Easily acquired in the diet.
Is excess manganese toxic?
Yes - leads to manganism (form of parkinsonism)
Newborns require only 3micrograms/day
What is the importance of iron in the body?
Required in many proteins:
- haem proteins
- non-haem proteins: ribonucleotide reductase, transferrin, ferritin.
- iron-sulphur proteins - aconitase, succinate, dehydrogenase.
How iron uptaken and transported in the body?
- Fe3+ must be reduced to Fe2+ for uptake via DMT1.
- Fe2+ is stored in ferritin as Fe3+ as iron oxide
- Feraportin exports iron(II) out of the intestinal cell along with hephaestin.
- Fe2+ is then oxidised to Fe3+.
- Fe3+ is transported in transferrin to wherever its needed.
What form of iron is uptaken by DMT1 into cells?
Fe2+.
What protein stores iron?
Ferritin
What protein transports iron out of the cell and in what oxidation state?
Feraportin - exports Fe2+ along with hephaestin.
In what oxidation state is iron transported around the body?
Fe3+ in transferrin
What protein transports iron around the body?
Transferrin
How is transferrin (iron) uptaken into cells?
- Transferrin binds to specidic receptor on the cell surface.
- Endocytosis form endosome containing transferrin.
- Endosome is acidified to cleave Fe from the protein.
- Empty transferrin is recycled to the cell surface.
How is iron released from transferrin in a target cell?
The endosome containing transferrin is acidified - causing iron to be cleaved from the protein.
What is iron deficiency?
Iron deficiency anaemia - insufficient amount of haemoglobin produced.
Blood cannot carry enough oxygen - usually become tired and short of breath.
What is iron overload?
Hemochromatosis (type 1):
- mutated protein which takes up too much iron.
- treated with phlebotomy.
- excess iron is deposited inorgans throughout the body causing damage to the organs.
What is the functions of zinc in the body?
Involved in basically all cellular processes:
- brain function (neurotransmitter)
- immunity
- provides protection against environmental toxins and toxicants.
What is the total amount of zinc in the body?
2-3g
What is zinc deficiency?
Causes stunted growth.
- suppressed immunity
- Dermatitis
-Poor wound healing
- delayed sexual maturation
- Impaired cerebral and peripheral nerve function.
5TH LEADING CAUSE OF MORTALITY AND MORBIDITY IN DEVELOPING COUNTRIES.
Give 2 genetic diseases associated with zinc deficiency.
Acrodermatitis enteropathica - severe skin lesions, completely curable with zinc.
Trnasient neonatal zinc deficiency - child who does not obtain enough zinc from mothers milk. Curable with Zn given to child.
Name 3 copper proteins and their functions.
Ceraloplasmin - ferroxidase
Cytochrome C oxidase - terminal electron acceptor for O2.
Tyrosine - melanin production
How is copper transported in the body?
Cu is chaperoned within the cell and transported by Cu-ATPase
What is copper deficiency?
Menkes disease (genetic) - NO CURE
- defective absorption of copper in th eintestines
- hair depigmentation, deterioration of the nervous system.
