What color indicates a positive result for ketoses in Seliwanoff’s test?
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Red color.
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What color indicates a positive result for ketoses in Seliwanoff’s test?
Red color.
What does the Ninhydrin Test detect?
The presence of ammonia, primary/secondary amines, or amino acids.
What is the expected result of Fehling's test for reducing sugars?
Red precipitate for Glucose, Fructose, Xylose, Lactose, Maltose.
What does Tollen's test detect?
Aldehydes (reducing sugars) based on the reduction of silver ions to metallic silver.
What is the expected result of Barfoed's test for disaccharides?
Little to no precipitate for Lactose, Maltose.
What happens to cottonseed oil when mixed with distilled water?
Cottonseed oil will not dissolve and remains on top because it is non-polar.
How does bromine water react with unsaturated fatty acids?
Bromine water reacts by breaking the double bonds in unsaturated fatty acids.
What gas is released when proteins are heated with soda lime?
Ammonia gas (NH₃).
What color change occurs in the Salkowski test for cholesterol?
Cholesterol reacts with sulfuric acid to produce a red or pink color.
What color indicates the presence of pentoses in Bial’s orcinol test?
Blue-green complex.
What is the expected result of the Lead Acetate Test for sulfur-containing amino acids?
Formation of a black precipitate of lead sulfide.
What is the expected result of Millon’s Test?
Formation of a red solution or precipitate.
What is the primary element detected in proteins during the nitrogen detection test?
Nitrogen in their amino groups.
What color change indicates the presence of cholesterol in the Liebermann-Burchard test?
The formation of a blue-green color upon acid addition indicates cholesterol presence.
What does Bial’s orcinol test detect?
Pentoses and pentosans.
What is the expected result of reducing sugars in Benedict's test?
Red or orange precipitate for Glucose, Fructose, Xylose, Lactose, Maltose.
What characteristic odor indicates the presence of ammonia during the nitrogen detection test?
Pungent, sharp ammonia smell.
What does Seliwanoff’s test distinguish between?
Aldoses and ketoses.
What effect do mineral acids have on proteins?
Cause protein precipitation by neutralizing charges.
What is the expected result of Barfoed's test for monosaccharides?
Red precipitate for Glucose, Fructose, Xylose.
What does a semi-translucent spot on paper indicate?
It indicates the presence of fats and oils.
How do proteins behave in distilled water during solubility tests?
Soluble.
What is the expected result of the Xanthoproteic Test for albumin?
Formation of a yellow precipitate, which turns orange with NH₄OH.
What is the purpose of Barfoed's test?
To differentiate between monosaccharides and disaccharides.
What types of sugars can be detected by the Molisch test?
Monosaccharides, disaccharides, and polysaccharides.
What is the expected result when cottonseed oil is tested with Hanus iodine solution?
The iodine color fades faster due to a higher number of double bonds in cottonseed oil.
What is the purpose of Benedict’s test?
To detect reducing sugars in a solution.
What does Fehling's test detect?
Reducing sugars by the reduction of copper(II) ions to copper(I) oxide.
What is the general solubility characteristic of lipids?
Lipids are generally hydrophobic (insoluble in water) and soluble in organic solvents.
What happens to pH paper when ammonia gas is present?
Turns blue due to its basic nature.
What is the result of protein coagulation when alcohol is added?
Formation of a precipitate.
What color indicates the presence of proteins in the Biuret test?
Violet color.
What does the Sakaguchi Test specifically detect?
Arginine.
What is the expected result of the Anthrone test?
A blue-green complex indicating the presence of carbohydrates.
What is the expected result for glycine in the Biuret test?
No color change.
What is the expected result of the Sakaguchi Test for arginine?
Strong red color forms.
What is the expected result when cottonseed oil is mixed with ether?
Cottonseed oil dissolves completely, forming a larger translucent spot.
How does the Anthrone test work?
It hydrolyzes carbohydrates into monosaccharides and then catalyzes their dehydration to form furfural derivatives.
What does the Xanthoproteic Test detect?
Amino acids containing phenolic or indolic groups like phenylalanine, tyrosine, and tryptophan.
What is a false-positive result in the context of reducing sugar tests?
Reactions with drugs like penicillin, isoniazid, streptomycin, salicylates, and p-aminosalicylic acid.
What is the expected result of Tollen's test for reducing sugars?
Silver mirror for Glucose, Xylose, Lactose.
What color indicates a positive result in the Molisch test?
A violet or purple ring at the interface.
What is the expected odor when proteins are burned?
Burning hair or feathers, characteristic of nitrogenous compounds.
What is the expected result of heating proteins?
Formation of a white solid (coagulated protein).
What color indicates a positive result in the Ninhydrin Test?
Purple or blue-violet color (Ruhemann’s purple).
What does Millon’s Test specifically react with?
Tyrosine, an amino acid with a phenolic group.
What does the Molisch test detect?
The presence of carbohydrates based on the dehydration of sugars by sulfuric acid.
