presentation problem: the lethality of cassava hypothesis :treating cassava with radiation can avoid...
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PRESENTATION
Problem: the lethality of cassavaHypothesis :Treating cassava with radiation
can avoid that.Aim is to decompose proteins enzymes that
cause the decomposition of cyanoglycosides.
Project : pesticide manufacturing
Contents.
• Introduction• Chemical description of( hydrogen cyanide and its
derivatives).• Industrial & laboratory production of HCN.• Uses of HCN.• Physiological description of Hydrogen cyanide
intoxication.• Antidote of HCN intoxication.• Different ways of preparing cassava tubers and leaves
in order to avoid their toxicity.• My project
Introduction
Cassava tubers and leaves are edible
Cassava plant & HCN
• Cassava plant is among major plants that are mostly cultivated in some tropical regions and it becomes the frequent food for population of those regions , NIGERIA is the first country that cultivate cassava in the world . Its tubers and leaves are edible either by direct consumption or after the transformations .thereby to get different food like Eba,fufu,..
• The tubers are potentially made of carbohydrates as the main source of nutrient rather than protein,but also the there exist small proportion of Cyanide compounds ,that exit in two carbohydrates forms(cyanogenic glucosides):LINAMARIN &LAUTOSTRALIN.
Chemical description of HCN
This is chemical structures of HCNHCN is easily dissociate in water or basic medium
HCN(aq) + H2O(l) = CN-(aq) + H3O+(aq).The anion CN- is the strongest nucleophile in all
substitution organic reactions or complex formation, as it is so-electronic with CO(carbon monoxide)
Industrial & laboratory preparations.
Industry scale[Andrussow process]
I)2CH4(g)+2NH3(g)+3 O2(g)/Pt → 2HCN+6H2O
Laboratory scale
H++NaCN→HCN+Na+aq
Uses of HCN
It is used as precursor of NaCN and KCN that are used in gold and silver mining .
HCN allows chemists to have CYNOHYDRIN as the intermediate compound in formation of many
important organic compound.
Physiological effect of Cynides(partI)
When CN- get into body by inhaling HCH or CN- in solution,it spread quickly in human body after the intake,
As we said in the root of cassava plant there exist two forms of cyanogenic gycosides that are decomposed naturally byenzyme called LINAMARASE,to give HCN which very toxic to human
and animalOnly 40mg of pure cyanogenic gycoside can directly kill a cow,as the concentration of that compound vary from[…………]according to the types of cassava plant and theirs seasons in
which they were planted.The bitter cassavas have much HCN,sweeter have less HCN.
The cassava of dry seasons have much HCN that of rainy seasons
Physiological effect of cyanides(partII)
When CN-get into body ,especial in blood system,as said above CN- is the strongest nucleophile ,it replace other nucleophiles attached on copper ion that makes respiration enzyme reason
why it impair the respiration by inhibiting the CYTOCROME OXIDASE,which is the respiratory enzyme in elecrton chain
transport ( important step of cellular respiration in ATP production).
As result man or animal can get in coma(ataxia), or death due to lack of ATP and oxygen cellular intake
ANTIDOTE OF HCNHydroxocobalamin is used as an antidote in order to
react with it and form cynocobalamin which non harmful,but after few minutes of intake.
(cynokit brandname).
+ -
Radiation cassava treatment.
1)Pre-plantation methods(genetic transformation)
2)Pre-consumption method(protein decomposition)
Pre-plantation radiation step
As the genes producing enzymes in cassava plant cells are able to be modified into
other genes,It is possible to shift the bitter
type into sweet one ,using genetic transformation( radiating these genes) for the plantation to
be introduced or Transforming them in the best type that can not produce any
enzyme among those that cause the HCN formation from
cynoglycosides.
Pre-consumption radiating method
The harvested tubers ,and leaves may be treated by radiation so that the unused enzymes that
transform glucosides into HCN , can be the antidote by neutralizing CN- physiological effect.
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