Minerals Flashcards
a bronsted-lowry acid is…
a proton (H+) donor
a bronsted-lowry base is…
a proton (H+) acceptor
a lewis acid is
an electron pair acceptor
a lewis base is
an electron pair donor
what is a coordinate covalent bond?
both electrons are supplied by one of the atoms of the bond
what is a coordination complex?
a metal (lewis acid) and ligands bound to it (lewis bases)
what is the coordination number?
the number of donor atoms bonded to metal atom or ion in the complex, most common is 4 or 6
what are chelating agents?
ligands/lewis bases with 2 or more donor atoms = molecules that have the ability to form more than one bond to a metal ion
what is a chelate?
a chemical compound composed of a metal ion and a chelating agent
what is a commonly occuring chelate agent?
porphyrin is the chelating agent in many chelates, like heme and chlorophyll
why are chelates important in biological function?
naturally-occuring chelates transport important nutrients throughout plants and animals, and they are important in many life-sustaining reactions
what is formed of positive metal ions in aqueous solution?
H2O molecules bind to the positively charged metal ion, forming the first coordination sphere (first solvation shell). these molecules can then attract more H2O molecules which form the second coordination sphere (second coordination shell)
what is the classification of trace or major minerals based on?
amounts present in and needed for the human body. major = present in amounts larger than 5g in an adult
what are the biological functions of calcium?
structural role in bones (skeletal strength and Ca storage to maintain calcium pools) - transmission of nerve impulses - maintains cellular structure - essential for muscle contraction
what are symptoms of calcium deficiency?
stunted growth, osteoporosis
where in the body is calcium found?
99% is in the bone matrix. the other 1% is in the body fluids (extracellular fluid, blood, cellular fluid)
calcium in body fluids exist in three forms, which?
50% free cation Ca2+ - 40% bound to proteins - 10% complexed with other ions
what part of calcium homeostasis is the most important to regulate?
blood levels! this is carefully regulated by hormonal systems interacting between thyroid, parathyroid, bone, kidney and gut.
calcium deficiency is handled by the body in what way?
Calcium receptors on the parathyroid gland are inactivated when Ca levels fall, and parathyroid hormone is released. Receptors in bone structure react to PTH and cause release of calcium from bone to blood. Receptors in the kidney decrease calcium secreiton. Kidney produces more vitamin D which signals to the intestines to absorb more calcium.
why could calcium be added in cheese manufacture?
it reduces the rennet coagulation time of milk due to the neutralization of negatively charged residues of the casein leading to the increase of the renneted micelles
what are the biological functions of phosphorous?
component of bones and teeth - cell membrane in phospholipid - acid-base balance - DNA/RNA structure - ATP - nerve transmission
what are symptoms of phosphorous deficiency?
muscle weakness. P deficiency is rare!
how much of dietary phosphorous can the body take up?
dietary phosphorous is easily absorbed, about 50%.
where do phosphorous and calcium interact?
in bone, a large molecular unit called hydroxyapatite is very important and contains both calcium and phosphorous
what are the biological functions of magnesium?
bone structure - protein synthesis - energy metabolism - muscle contraction - critical to heart function
what are symptoms of magnesium deficiency?
hypocalcaemia(reduced effect of PTH give lower calcium levels), cardiac and neurological manifestations. diabetes, hypertension, coronary heart disease, osteoporosis. magnesium is a very important cofactor in many processes in the body.
why is magnesium important for energy metabolism?
it stabilizes stored ATP which otherwise easily falls apart to ADP+P
magnesium has two functions in bones, which?
70% is in the bones and give physical structure, 30% are on the bone surface and act as a storage site for magnesium
how do magnesium and calcium interact?
they are antagonists! overlapping transport system in kidney and gut mean that they compete for absorption and re-absorption. magnesium decreases calcium flux across cell membranes causing muscles to relax. also competes with calcium for non-specific binding sites on troponin C, one of the proteins involved in muscle contraction
why do calcium, phosphorous and magnesium need to be regulated?
concentration in blood needs to be stable due to being involved in nerve signaling and muscle contraction
what is an electrolyte?
a mineral that dissolves in water and carries an electrical charge
where are electrolytes found in the body?
everywhere - inside the cells, between cells, in blood, lymph glands and everywhere else since they are important in fluid balance and osmosis
what are the biological functions of sodium?
it is the principal electrolyte in animals. it is important in fluid volume and the ionic balance.
sodium deficiency shows as
muscle cramps, mental apathy, loss of appetite
sodium toxicity shows as
edema and hypertension
what are some food industry advantages of sodium?
it enhances other flavors, salty taste, raises boiling point of liquids (cooking pasta), masks bitter taste, used in food safety for its water binding properties
what are the biological functions of potassium?
electrolyte - fluid balance - protein synthesis - nerve transmission - contraction of muscles
potassium deficiency shows as
muscle weakness - paralysis - confusion
potassium toxicity shows as
muscle weakness
how well is potassium absorbed by the body?
well absorbed from the small intestine, about 90% absorption, although it is very soluble and thus easily lost in cooking
what are the biological functions of chloride?
electrolyte - assists in conduction of electrical impulses - fluid balance - protein synthesis - nerve transmission - contraction of muscles - HCl in stomach
what are the biological functions of sulfur?
important for protein structure . part of biotin (b7) and thiamin (b1) and of insulin (disulfide bridges between alfa- and beta-chain of insulin)
what are symptoms of sulfur deficiency?
none known because protein deficiency would occur first
what are the biological functions of zink?
part of metalloenzymes - stabilisation of molecular structure of cellular components and membranes contributing to the maintenance of cell and organ integrity - immune function
what are symptoms of zink deficiency?
growth retardation - delayed sexual and bone maturation - skin lesions - diarrhoea - impaired appetite - increased susceptibility to infections - behavioural changes
where in the body is zink found?
57% in skeletal muscle, 29% in bone
what are the biological functions of copper?
part of metalloenzymes like superoxide dismutase (handles ROS), synthesis of hemoglobin and collagen, production and activation of neutrophils (vita blodkroppar)
what are symptoms of copper deficiency?
it is rare. neurological problems - poor temperature control - connective tissue degeneration - bone mineral loss - anemia - poor hair and skin quality. probably has a role in diabetes and CVD
how do zink and copper interact?
they have both synergistic and antagonistic relationships. zink reduces copper uptake which weakens neutrophil action.
what are the biological functions of manganese?
activates many enzymes in cell metabolism - in vitamin utilization - protein digestion
what are the biological functions of iodine?
none as ion, but: part of thyroid hormones and thus energy metabolism - body temperature regulation - reproduction and growth - nerve and muscle function
what are symptoms of iodine deficiency?
decreased function of thyroxin and enlargement of thyroid glands
what are the biological functions of selenium?
involved in activation of thyroid hormone conversion of T4 to T3 - antioxidant
what are the biological functions of cobolt?
as chelate forming vitamin B12
what are the biological functions of iron?
involved in oxygen transport via hemoglobin - essential component of many enzymes including toxic/foreign substance metabolizer cytochrome P450 - regulation of cell growth and differentiation - immune function - brain function
what are symptoms of iron deficiency?
deficiency limits oxygen delivery to cells causing fatigue, poor work performance, decreased immunity
where in the body is iron found?
2/3 is in hemoglobin
what is the difference between heme and nonheme iron?
heme iron is well absorbed (about 25%). nonheme iron in other compounds is less well absorbed (17%)
how is iron transported in the blood?
bound to the glycoprotein transferrin which only can bind two iron atoms. normally 20-45% of transferrin binding sites are filled. in excess of dietary iron, the body responds by producing more ferritin (a storage protein containing iron).
which maintains normal fluid and electrolyte balance? P, Cl, Zn or Ca?
Cl!
heme iron is found in
meat
magnesium is important for which of the following? energy production, enzyme activity, muscle contraction and relaxation, all of the above
all of the above
how are minerals affected by heat?
they are generally not sensitive to heat during processing but are susceptible to leaching into the processing or cooking water.
how much manganese, cobalt and zinc may be lost during canning of spinach, beans and tomatoes?
more than 50% if the liquid is not consumed
how much manganese, iron, copper, phosphorous, zinc, calcium could be lost in pasta cooking?
86,5-100%
in which steps of processing and digestion do we talk about bioavailability?
intestinal absorption, cellular absorption and functional material. not in processing or digestion
what dietary factors affect bioavailability?
physicochemical form of the minerals - presence of enhancers like vit C for iron - presence of inhibitors like polyphenols - competitive inhibitors for transport protein binding or adsorption sites
what physiological factors affect bioavailability?
gastric acidity and intestinal secretion - body status - anabolic demands like infant growth, pregnancy, lactation - infections and stress - genetic influences, metabolic degeneration and errors - gut microflora
what is the action of phytic acid?
it is a sugar (inositol) with six phosphate groups. these phosphate groups give very strong negative charges (depending on pH) that can bind to positively charged metals like Zn, iron and Ca.
what are universally harmful trace elements?
arsenic (heart function), cadmium (kidneys, skeletal growth), lead (kidneys, fertility, nervous system and heart), mercury (nervous system and fertility), aluminum (nervous system and skeleton)
