bioinorganic chem Flashcards
where are the elements necessary for life found?
-in the first 4 periods of the periodic table
what are the 4 main categories the elements necessary for life are in?
-bulk elements
-macro-minerals and ions
-trace elements
-ultra trace elements
what are the bulk elements?
-H,C,N,O,P,S
what are the macro minerals and ions?
-Na,K,Mg,Ca,Cl,Po4^-3
what are the trace elements?
-Fe,Zn,Cu
that are the ultra trace elements?
-non metals=F,I,Se,Si,As,B
-metals-Mn,Mo,Co,Cr,V,Ni,Cd,Sn,Pb,Li
why are these elements and ions essential for humans?
-on removal of these elements from your diets physiological deficiency appears
-the symptoms are relieved by addition of the element to the diet
-the specific biological function is associated with the element
what dose the dose-response curve show?
-the essential element dosage needs to be optimal, any lower and deficiency can occur, any higher and toxicity can occur
how much iron does the average adult body contain?
3.5-4.5g of iron
-there is 70% in haemoglobin,3% in myoglobin and 1% in blood plasma
-the remaining is in protein-iron storage complex ferritin and haemoglobin
what do iron complexes have in common?
-tweo common oxidation Staes Fe III (ferric iron) and Fe II (ferrous iron)
what is most of the iron in our food?
-most of the iron in our food is ferric iron and it is converted by reducing agent such as vitamin C into ferrous iron that is of more use in the body
how can iron be lost from the body?
-it can be lost in small quantities through sweating the urine and faeces
why do women iron levels tend to be much lower than mens?
-menstruation in women results in the major loss of iron from the body
what is the link between iron and haemoglobin?
-iron is an essential element in the production of haemoglobin
what is the structure of iron and how does this help us?
-it is present as Fe II and has an octahedral shape that can bind to 6 ligands
-in haemoglobin, 5 of the ligand spaces are already occupied but the 6th can be used to bind other ligands such as molecular oxygen and this enables oxygen to be transported around the body in red blood cells which are packed with haemoglobin
what can cause iron deficiency?
-low level of iron in the diet (iron is mainly found in red meat but also in some green veg)
-excessive bleeding (pile, duodenal ulcers)-this is a sign of internal bleeding
what can a deficiency in iron result in?
-a fall in the conc of haemoglobin
-reduction of red blood cells circulating the body-this is anaemia and results is feeling fatigue or apathy
what can an excess uptake of iron cause?
-haemochromatosis
-iron compounds are regularly used as iron supplements e.g iron II sulphate,these often have side effects such as nausea,vomiting,constipation,diarrhoea and blackening of teeth and faces
what is haemochromatosis?
-a general depositing of iron that leads to tissue damage.This can lead to liver and pancreas damage resulting in diabetes mellitus and heart failure
how much magnesium does the human body contain?
-around 25g, there is around 50% in bones
what is the functions of magnesium in the human body?
-It is a co factor for many enzymes and hormones (DNA polyerases have an active site requiring Mg2+ to be bound for them to function)
-Regulates nerve function,muscle contractions
-Stabilises bio-molecules such as DNA,RNA and proteins
what can a deficiency in magnesium cause?
-loss of appetite
-convulsions/epilepsy
-muscle tremors
-constipation
-changes in heart rhythm
what can an excess of magnesium cause?
-a decrease in muscle response, this makes it act as a laxative
what are the different magnesium drugs?
–Mg supplements
-antacids (magnesium carbonate)
-laxatives (magnesium hydroxide)
