minerals Flashcards
What does angiotensin do?
Causes vasoconstriction of the blood vessels (which activates the kidney)
Name the two main functions of Na+?
- maintains electric potential in the membrane and conducts nerve impulses
- absorption of nutrients
What symptoms does hypo-na-tremia show?
Headache, seizure, confusion and coma
What symptoms does hyper-na-tremia show?
Odema, thirst, high blood pressure
How is hypo-na-tremia caused?
Vomiting, sweating, diahorrea
How is hyper-na-tremia caused? (3)
Excessive fluid loss via. vomiting etc.
Renal failure - too much Na+ absorption
Not enough water
Main role of Iodine?
Homornal synthesis in the thyroid of thyroxine (T4) and its active from T3
What form is Iodine uptaken and what does it get converted too + how?
I- ions, combine with H2O2 to form I2 which forms tyrosine
Where is Iodine levels the highest?
Thyroid gland, salivary and then gastric glands
How is excess Iodine excreted?
Excreted through our urine
Name 4 roles of the thyroid gland
- Metabolic function
- Growth and development
- RBC cell synthesis
- Thermogenesis
What is the thyroid gland crucial too?
Development of the central nervous system in children and foetus
Three symptoms of hypo-thyroidism (aka. Iodine deficiency)?
- Weight gain
- High cholesterol levels
- Reduced lypolysis, gluconeogenesis
Called hypo-metabolism
Three symptoms of hyper-thyroidism (aka. Iodine deficiency)?
- Weight loss
- Low cholesterol levels
- Increased lypolysis, gluconeogenesis
Called hypo-metabolism
Severe case of Iodine defiency? (Name and symptom)
Goitre - irreversible mental retardation and cretinism (non reversible) - especially if during key growth development in children
How have the public health tried to increase Iodine levels?
Iodization of oil, salt and water
Environmental factors of autoimmune thyroid diseases? (4)
- Naturally occurring goitrogens reduce I2 bioavailability
- Heavy metal ions (e.g. Lead)
- Polychlorinated biphenyls
- Organochlorine compounds (man-made) found in pesticides
Main role of Se?
Incorporated into amino acids to make proteins
Sources of Se?
=crops - low conc. as not essential for their growth
How do plants uptake Se?
Se-methionine, Selenite/Selenate
How do animals uptake Se? and why do they vary?
Se-methionine, Selenite/Selenate, Secys and because of diet
What atom does Se replace and how does it change the protein functionality?
Sulphur, makes the proteins more reactive
Which has more Se bioavailability plants or animals?
Plants
Which is absorbed more readily, inorganic or organic forms of Se?
Organic
What is the central species for Se utilization and excretion and how is it made?
Se reduced to H2Se
What vitamin is mainly associated with Se?
Vitamin E- recycled after e- donated to free radical (anti-oxidant), then Glutathione is regenerated by vitamin C
What is the enzyme associated with Vitamin E recycling?
Glutathione peroxidase
Which two countries have low Se soil?
China and UK
Two conditions of Se deficiency?
- Keshan - heart disease
2. Keshin-Beck - joint deterioration
Symptoms of Keshan?
Cardiomyopathy, fatal heart muscle disease - 2-10years
Symptoms of Keshin-Beck?
osteoarthritis - joint muscle degeneration and death - 5-13years
What is Zn main function?
Incorporated into proteins:
structural, catabolic (enzymes), co-factors, intracellular and extracellular cell signalling
How does Zn exist?
Zn2+
How is Zn different to the other micro elements?
It isn’t redox active
Name 4 elements Zn deficiency or excess can effect?
- Growth
- Morphentic functions
- Immune response
- Neuro-sensory and endocrine functions.
When is Zn requirement higher?
During pregnancy, lactaction and during puberty
How many enzymes require zinc?
300
How many transcription factors require zinc?
2000
Name 3 roles that Zn is important for?
- Anti-inflammatory
- Anti-oxidant
- Cell-mediated immunity
Are there stores of Zn
no
Are low or higher intakes of Zn easier to absorb
lower
Name two zinc transporters?
- Zrt or Znt
2. ZIP
How does the absorption of Zn differ
There is a differential expression of the sub-cellular location of transporters, eg. some on membrane and some associated with organelle systems
What symptoms can Zn deficiency cause? (5)
- Cold - lower immune system
- Growth retardation
- Increased oxidative stress
- Testicular hypofunction
- Increased generation of inflammatory cytokines
How much Zinc should we have a day
5-10mg
Which diet is best for Zn defiency?
Low in phytates and high in animal protein
What do phytates do?
Lower bioavailability of minerals
What is special about Zn deficiency source
It isn’t necessarily linked to low Zn levels in food
