Chemistry - part4 Flashcards
Name some of the trace elements
- Baron. - Silicon
- Chromium
- Cobalt
- Copper
- Fluorine
- Iodine
- Iron
- -maganese
Iron (Ferrous Fe2+ and Ferric Fe3+)
- key role in the metabolism
- one of the most abundant mineral on earth (most is in the insoluble form) (non-harm / Fe3+)
- iron from animal sources more easily absorbed (haem / Fe2+)
Iron that is more easily absorbed is from
animal sources
What help convert plant source iron (Fe3+) to the more easily absorbed form iron (Fe2+)?
Vitamin c
Where does iron get absorbed most effectively in human body?
first section of small intestine (duodenum)
iron absorb % by
- healthy people
- deficient people
healthy - 5-10%
efficient - 10-20%
Periodic table detail of Iron
- no of proton
- symbol
- atomic mass
- 26
- Fe
- 55.85
What are the two forms of Iron that gets stored in our body?
- ferritin (iron storing protein-40% in the liver)
2. haemosiderin- only found in cells.
how does iron is transported in the plasma
by transferrin the iron transport protein
Essential organ for normal iron homeostasis in the body is
The liver
how does liver help maintain normal iron homeostasis?
regulates iron movement through hepcidin* synthesis and synthesizes major proteins of iron metabolism such as transferrin and ceruloplasmin
Roles of iron
- needed in red blood cells (carries 70% of iron) to form haemoglobin
- haemoglobin carries oxygen to all the body tissues
- haemoglobin carries some of the carbon dioxide from the tissues back to the lungs
- in muscles (in myoglobin cells) iron provides oxygen for activity
- involved in chemical reactions for respiration and producing energy, synthesis of some neurotransmitters and collagen (6%)
- Levels of iron tightly regulated
one haemoglobin molecules can build up to ________ molecules
four oxygen
Sources of iron
Animal/fish sources:
- oysters, liver, kidney, chicken leg, lamp chops, pork roast, sardines, etc..
Plant sources:
- Lentils, tofu, weet-bix, dried peaches, dried beans-kidney, backed beans
milk and dairy products are poor source of iron.
Daily requirement of iron
- 18mg/day for women 19-50
after menopause-and other adults about 8mg/day
amount of iron stored in average adult male?
1000 mg (enough for 3 days)
amount of iron stored in average adult women?
300 mg
Factors which decrease iron absorption
- rapid transit time (diarrhoea)
- absence of hydrochloric acid and enzymes in the gastric secretions
- malabsorption syndromes
- precipitation by use of an alkali product e.g. anti-acid preparations
- phosphates (often in soft drinks)
- Phytate* (bran, maize, rice and nuts)
- milk products and soy proteins
- tea and coffee (60% tea, 40% by coffee)
- zinc salts (medicines)
iron deficiency can lead to
- anaemia with substantial reduction in work capacity
- impaired temperature regulation
- impaired psychomotor development and intellectual performance (memory and learning)
- changes to behaviour
- less resistance to infection
- increased risk of lead poisoning, as iron deficient individuals absorb more lead.
three factors that can affect low iron
- Demographic factors (Elderly, teenager, female, immigrants, widower)
- dietary factors (low iron, low vitamin c, excess tea/coffee, etc..)
- Social/physical factors (poverty, poor detention, depression, alcohol abuse)
Zinc
- an element in m any enzymes
- helps maintain structural integrity of proteins
- regulate gene expression, reduces tumour growth
- regulate cell signalling pathways
- low in NZ soil
- abundant in nervous system, 86% in muscle and bone
Ros full form
reactive oxygen species
oxLDL
oxidised low density lipoprotein
What is NF-kB and its role
protein complex. plays key role in regulating the immune response to infection
what is PPAR
major regulator of lipid metabolism
Daily requirement of Zinc for both men and women
Adult women - 8mg/day
Adult men. - 14mg/day
Factors that influence the absorption of zinc
- fermentation of leavened bread and porridges reduces the phytate content and improves zinc absorption.
- zinc absorption is maximum when taken by itself in an aqueous solution in a fasting state
- food sources easily extracted in the acidic conditions of the stomach
- high phytate content of diet blunts Zn absorption significantly
Absorption site of zinc
small intestine (the jejunum)
sources of zinc
meat, liver, eggs and seafood
Organ that maintain homeostasis of whole body zinc content is…
The gastrointestinal tract
Zinc deficiency leads to
- growth retardation
- delayed puberty
- poor appetite, impaired taste, appetite and food intake
- diarrhoea, intestinal inflammation
- hypogonadism
- alopecia (hair loss)
- skin lesions, glossitis, nail malformation
- immune dysfunction and susceptibility to infection*
- behaviour disturbance
- delayed wound healing of wounds, burns decubitus ulcers
- photophobia, night blindness
Excessive zinc supplements leads to
- copper deficiency
- low serum HDL level (high density lipoproteins: good cholesterol)
- gastric distress, dizziness and nausea.
- depressed immune function
Safe does of zinc per day
<50mg/day
name two families of zinc transporter proteins
- ZnT - (SLC30A): 10 mammalian- facilitate zinc out of the cell membrane.
- ZIP (SLC39A) 14 mammalian-facilitate zinc entry from cells or from vesicles.
Genetic disease associated with these transporters
ZnT2 – low zinc in breast milk
ZnT8- type 1 and 2 Diabetes
ZIP1, ZIP4, ZIP6 ZIP7, ZIP10, ZIP14 –prostrate, pancreatic, colon, or breast cancers
ZIP4 - acrodermatitis enteropathica* – zinc malabsorption
ZIP13 Ehlers syndrome+
ZIP14 –iron overload
Selenium
- discovered by Jons Jacob Berzelius, in 1817
- in 1957 found essential to all mammalian life
- Is an antioxidant
use of selenium
- good electric conductor and used in many electronic device e.g. photo cell
- Used for removing or adding stain in glass or enamel (red)
- A catalyst for the production of active thyroid hormone
- Important to the immune system
- May inhibit HIV progression to AIDS
- May reduce the risk of miscarriage
- Low selenium levels in NZ men associated with prostate cancer
- Selenium in NZ soils is low
what are the two main forms of selenium ingested.
selenomethionine and selenocysteine
where does homeostatic mechanisms regulate the selenium
in the cell
The amount of selenium absorbed depending on
nutrients in the diet and intestinal factors
sources of sodium
animal: poultry, eggs, seafood and meat
plant: grains, Brazil nuts
chives, garlic and onion, Indian mustard and canola - rape seed oil and some mushroom
Daily requirement of selenium
adult males 70ug/day
adult women 60ug/day
factors that influence absorption of selenium
- Minerals soil content
- how the food is processed (boiled - mushroom and asparagus gets reduced by 40%)
- adding salt and vinegar to food contribute to selenium loss
- The antioxidant level of the diet can change the amount of selenium needed
- individual needs: may vary according to -lifestyle, degree of activity and whether they smoke.
Selenium deficiency linked to
- deficiency disease in livestock e.g. sheep and cattle
- low survival rate in people with HIV
- number of disease linked with low selenium level e.g. prostate cancer
- neurological disorder associated with old age and seizure in both children and adults
- male infertility
- depression and anxiety
who’s work provided the first evidence that Se may reduce the incidence of prostate, lung and colon cancers
Larry clark
Selenium intake of ____ or above is toxic
400ug/dau
Selenium toxicity symptoms
- garlic breath
- hair loss
- brittle nails
- gastrointestinal symptoms
- skin rash
- fatigue and irritability
Iodine
- important constituent of thyroid hormones
what is responsible for regulating the iodine metabolism
thyroid glands which produce thyroid hormones knows as T3 and T4
deficiency of iodine leads to….
- decreed production of T3 and T4
- this enlarges the thyroid gland i.e simple goitre
Daily requirement of iodine
adult men and women 150ug/day
Dietary sources of iodine
- seafood (fish, shellfish and seaweed)
- commercially prepared bread
- iodised salt
- milk and eggs
Factors that influence the availability of iodine
- iodine content of NZ soil is low, so local vegetables, fruits and grains has low iodine
- animal feed iodine content will reflect in meat, chicken, eggs and dairy
- requirement of iodine increase during pregnancy and breastfeeding.
iodine deficiency
- goitre, increased susceptibility of the thyroid gland to nuclear radiation. (all ages)
- Abortion, stillbirth, congenital anomalies, perinatal mortality (fetuses)
- impaired mental function, delayed physical development, reduced work productivity, etc…
very high intakes of iodine may inhabit__________ production
thyroid hormone
where do you find fluoride
in the earth crust
fluorine is the most electronegative element T/F
true
fluorine is extremely reactive T/F
true
level fo fluoride in water depends on which factors
- on the type of water (surface or groundwater)
- types of rocks and mineral the water contacts.
source of fluoride in NZ
Volcanic rocks and soils, geothermal fluids
which contain more naturally occuring fluoride surface water or ground water?
ground water
NZ recommended level for fluoridating drinking water is____
0.7-1.0 mg/L
High concentrations of fluoride in groundwater associated with _____.
natural fluoride levels?
- granites and gneisses
- 0.2-20mg/L
recommended intake of fluoride per person per day is___
4.0 mg
if fluoride reaches concentration of ___ it is toxic
250-450mg/L
excess fluoride leads to
- mild to severe dental fluorosis (staining or pitting of the teeth)
- skeletal fluorosis (accumulation of fluoride in the bone)
- non-skeletal fluorosis (the soft tissues and organs) e.g renal, gonadal
sign and symptoms of excess fluoride
pain in stomach, loss of appetite, polyuria, muscle weakness, constipation followed by diarrhoea
benefit of fluoridated water within intake limit
- reduced severity of tooth decay
- better teeth
- Low concentrations of fluoride in the saliva decrease the rate of demineralization
- Fluoride has an antimicrobial effect on the bacteria in plaque
- Fluoride in low concentrations inhibits the bacterial enzymes, reduces acid production that causes tooth decay
