Qualitative tests of functional groups in carbohydrates, proteins

 Aim:-   Detection of  Protein /Carbohydrates

Preliminary test for identification of unknown substance from sample 

 

	Test	Observation	Inference
(1)       (2)       (3)	Preliminary Test       Heat test→ O.S heat in a.t.t     Biurate test O.S+few drop+10% CuSo4+10% NaOH +alkaline	Co-agulation        Violet colour       No violet colour	Protein  may be present carbohydrates may be present.     Protein may be present.       Carbohydrate may be present.

 

 

Test for Protein

 

	Test	Observation	Inference
(1)             (2)         (3)       (4)	Precipitation of proteins with heavy metals  O.S+Hgcl2 drop by drop + lead acetate       Colour reaction +proteins O.S+ 2ml of 40% NaOH +2ml 0.5%.CuSo4.        Xantho protein Recn  O.S + 1ml HNO3(conc.) & then boil     Million test:- o.s. +2ml HgSo4 boil cocl+ few drops of NaNO2 then heat	White ppt.              Violet colouration         White ppt turns Yellow after boiling        Yellow to dark red ppt	Protein present           Protein may be present.            Protein confirmed          Protein confirmed

 

Result: The given  sample is protein.

 

 

Test for carbohydrates

 

	Test	Observation	Inference
(1)       (2)       (3)           (4)	Preliminary Test       Heat test→ O.S heat in a.t.t     Biurate test O.S+fewdrop+10% CuSo4+10% NaOH +alkaline      Iodian test:- O.S+ 3 to 4 drops of I2 soln	Co-agulation        Violet colour         No violet colour            Blue colour No blue colour	Protein  may be present carbohydrates may be present.     Protein may be present.     Carbohydrate may be present.              Starch may be present reducing or non reducing sugar may be present.

 

Result: The given  sample is carbohydrate.