Exp. 1 Extra Flashcards
Protein is linked together with peptide bonds with a positive charged_______-containing group at one end and a negatively charged ________-group.
nitrogen
carboxyl
Biuret test is conveniently used to detect the presence of_______ or_______ in biological fluids.
It produces a_______ color.
proteins or peptide bonds
purple
Ninhydrin Test is to detect the presence of free alpha-____acids,_____,__________ and_______
amino
proline
hydroxyproline
asparagine
Ninhydrin test
It produces:
deep violet/blue color = _______
yellow-orange = for _______ and _______
brown color = for________
free amino acids
proline and hydroxyproline
asparagine
Hopkins- Cole
Test detect the presence of ______.
It produces a_____ color.
tryptophan
violet
Sakaguchi test
To detect the presence of______ in either free form or in proteins.
It produces a______ color.
No red-color means presence of ______ or ________.
arginine
red
glycine or albumin
Xanthoproteic
To detect the presence of _____, ______, and _______.
tryptophan, tyrosine and phenylalanine
Xanthoproteic It produces:
yellow color to _________ and;
orange with the presence of an____.
nitro derivatives
alkali
Biuret is a compound formed by heating____ at 1800 which results in the condensation of 2 molecules of urea
urea
It is considered as a general test for compounds (proteins and peptides) having two or more peptide (CO-NH) bonds
Biuret
This test is a general test and is thus given by all amino acids
Ninhydrin
is a powerful oxidizing agent and its presence, amino acid undergoes oxidative deamination liberating ammonia, CO2, a corresponding aldehyde, and a reduced form of ninhydrin (hydrindantin)
Ninhydrin
The NH3 formed from an amino group reacts with another molecule of ninhydrin and is a reduced product (hydrindantin) to give a deep blue or purple substance diketohydrin (_________purple).
Rheumanns
In ninhydrin test:________, which has a free amide group, reacts to give a brown-colored product.
Asparagine
ninhydrin does not react strongly with
tyrosine, tryptophan, and phenylalanine.
The indole group of_______ reacts with glyoxylic acid in the presence of conc. H2SO4 to give a purple colour.
tryptophan
Glyoxylic acid is prepared by reducing_______ with ________ or _________.
oxalic acid
magnesium powder or sodium amalgam
Sakaguchi test is based on the principle of reaction between 1-naphthol and the______ groups in arginine, in the presence of an oxidizing agent.
guanidinium
Xanthoproteic test is based on the fact that aromatic groups in the amino acids are nitrated by heating with____________ to yield intensely yellow-colored nitro derivative.
concentrated HNO3
Xanthoproteic: On the addition of______, however, the residue turns orange due to the formation of a salt of the tautomeric form of the nitro compound.
alkali
Benzene ring-containing amino acids like phenylalanine don’t give a positive test to this test because the phenyl group in phenylalanine is very stable, which doesn’t react with nitric acid in the conditions of this test.
Xanthoproteic
