Minerals
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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