Statistics for forensic toxicology - plant toxins - glycosides

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Answer Stats

Hint	Answer	% Correct
what is cyanide?	a glycoside with the aglycone cyanide (HCN) - a cyanogenic glycoside	100%
what are glycosides?	any molecule in which a sugar is bound to another functional group via a glycosidic bond	100%
what is the LD50 of cyanide?	1.5mg/kg	0%
what are saponin glycosides?	amphipathic molecules consisting of a hydrophilic glycoside coupled to a hydrophobic aglycone (they are detergents)	0%
what have cardiac glycoside drugs been used to treat?	arrhythmias and congestive heart failure	0%
how can this lead to a toxic effect?	because the cells are unable to use oxygen for metabolism, they essentially die through hypoxia	0%
	can also block acetylcholinesterase	0%
what are the types of glycosides we're interested in for this unit?	cardiac (steroidal) glycosides	0%
	CN- attaches to the iron in cytochrome c oxidase (a+a3)	0%
	cyanogenic glycosides	0%
what is an example of a cardiac glycoside drug?	digoxin	0%
	final symptoms: seizures and cardiac arrest	0%
	increased Na+ levels also inhibits the NCX pump, which brings Na+ in and moves Ca2+ out	0%
what are the physiological consequences of cyanide toxicity?	initial symptoms: weakness, confusion, dizziness, headache, and cherry-red skin	0%
how has the mechanism of action of cardiac glycosides allowed them to be developed into a therapeutic medication?	in low doses, it helps the heart muscle to contract	0%
what is the mechanism of action of cyanide?	in solution HCN produces cyanide ions (CN-)	0%
	saponin glycosides	0%
what is a aglycone?	the non-sugar part of a glycoside	0%
what is their toxic action?	they are haemolytic and cause lysis of red blood cells if injected	0%
	they bind to the pump and stabilise it in a transitional state (meaning it can no longer move Na+ out of the cell, so concentration in the cell decreases	0%
what is the mechanism of action of cardiac glycosides?	they target Na+/K+ pumps in cell membranes	0%
	this binding prevents the transfer of electrons from cytochrome c to oxygen	0%
	this is followed by loss of consciousness	0%
	this means Ca2+ level in the cell also increase, which is taken up by the sarcoplasmic reticulum	0%
	this shuts down the mitochondrial electron transport chain	0%
	toxic action is primarily through membrane disruption	0%
	when Ca2+ is release, myocyte contraction is faster and more powerful	0%
	which means the cell is no longer capable of aerobic respiration	0%