Medicinal Inorganic Chemistry 3 Flashcards
Name 3 alkali metals
Lithium
Sodium
Potassium
Where are alkali metals found in the periodic table?
First vertical column
= s block metals
Describe the structure of alkali metals
Only 1 electron in their outer shell = outer electron of an s-orbital type
Low ionisation energy
Most compounds of group 1 elements tend to be ionic in nature
Which alkali metal has the greatest ionisation energy?
Lithium
Which alkali metal has the lowest ionisation energy
Francium
Which element has the lowest melting and boiling point?
Francium
Which element has the highest melting and boiling point?
Lithium
Which element has the greatest atomic radius?
Francium
What state are alkali metals found in?
As salts, not in elemental state
How are alkali metals extracted from salts?
Electrolysis starting from NaCl
What is oxidation?
Loss of electrons
What is reduction?
Gain of electrons
Give an example of a reduction equation, oxidation equation and its overall redox reaction
Reduction: Fe –> Fe(2+) + 2e-
Oxidation: Cu(2+) –> Cu +2e-
Overall redox: Fe + Cu(2+) –> Fe(2+) + Cu
What does an increase of oxidation state imply about the gain or loss of electrons?
Increase in oxidation state = loss of electrons
What is the general reduction equation?
Oxidant + e- –> Product
i.e. gain of electrons
What is the general oxidation equation?
Reductant –> product +e-
i.e. loss of electrons
Describe 3 properties of alkali metals
Very reactive
Soft
Storage under oil or oxygen free atmosphere
Name 2 industrial uses of lithium
Batteries
Glass manufacture
Name 2 clinical uses of lithium
Manic depression
Bipolar disorder
What form is lithium in so it can be taken orally?
Li2CO3 - least irritating to GI tract
Total dose of up to 30 mmol/day
Very narrow therapeutic index
How does lithium act in the body?
Alters magnesium balance in blood and urine - Li+ displaces it
Lithium not soluble in lipids so will not cross plasma membrane
Exchange into cells by lithium-sodium counter-transport and anion exchange
List 3 side effects of taking Lithium
Tremors - usually in fingers
Memory problems
Weight gain
Why should NSAIDs and lithium not be taken concurrently?
NSAIDs cause reduced clearance of lithium through kidneys - lithium poisoning possible
Why should diuretics and lithium not be taken concurrently?
Sodium depletion makes lithium toxicity worse = hazardous
List 3 biological roles of sodium
Osmoregulation = maintenance of body fluids
Functioning of neurons and transmission of nerve impulses via build up of electrostatic potential across cell membranes
Passive transport mechanism
Define: Osmosis
The physical process of diffusion of a solvent (water) through a semi-permeable membrane towards an area of high solute (salt) concentration
= Equalises the concentrations
Define: Hypertonic solution
The solution has a higher concentration of solutes than the surrounding area
This area will gain water through osmosis
Define: Isotonic solution
The solution has the same concentration of solutes as the surrounding area
No movement of water will occur
Define: Hypotonic solution
The solution has a lower concentration of solutes than the surrounding area
This area will lose water through osmosis
Define: Hypernatraemia
High plasma concentration of sodium
>145 mmol/L
Name a consequence of hypernatraemia
CV disorders e.g. hypertension
Define: Hyponatraemia
Low plasma concentration of sodium
Result of dysfunctional kidneys or sodium loss in bowels
How does hyponatraemia harm the body?
Causes damage to the body via osmotic imbalances
List 3 signs of sodium deficiency (hyponatraemia)
Low blood pressure
Dehydration
Muscle cramps
List 3 symptoms of sodium overdose
Vomiting
Ulceration of GI tract
Renal damage
How does potassium enable cell-cell communication?
Causes a short-lasting change of the membrane potential
What are the 2 types of action potential that occur in animal cells?
Opening of calcium ion channels = longer lasting
Sodium/potassium-based action potential = shorter lasting
Where is the sodium/potassium-based action potential found?
Mostly found in the brain and nerve cells
Because it is so short-lived
Explain the Na+/K+ -based action potential
The osmotic balance between the cells and the interstitial fluid is altered
K+ concentration in and outside the cells is regulated by the Na+/K+-ATPase pump
3 Na+ ions are pumped outside the cell, 2K+ ions are actively transported into the cell using ATP
Therefore an electrochemical gradient over the cell membrane is created = resting potential
List 2 symptoms of hyperkalaemia
Nausea and vomiting
List 3 treatment options for acute hyperkalaemia
Diuretics
Dialysis
Calcium gluconate IV
List 3 causes of hypokalaemia
Reduced potassium intake
Increased excretion
Diuretics treatment
