Iodine Test for Polysaccharides Quiz

What is the primary purpose of the iodine test?

• To measure the acidity of a solution

• To detect and distinguish certain polysaccharides

• To identify proteins in a sample

• To determine the pH level of a substance

Who first described the iodine test?

• Jean Lugol

• J.J. Cullen and H.F. Gottierdo Clubri

• F. Stromer

• Louis Pasteur

What type of linkage results in a helical structure in polysaccharides?

• Beta-1,4 glycosidic bonds

• Alpha-1,4 glycosidic bonds

• Peptide bonds

• Disulfide bonds

Which polysaccharide gives a blue-black color with iodine?

• Amylose

• Dextrin

• Glycogen

• Amylopectin

What is the role of polyiodide ions in the iodine test?

• They act as a catalyst

• They form colored absorption complexes

• They neutralize the solution

• They dissolve the polysaccharides

What factor does NOT affect the resulting color in the iodine test?

• Length of glucose chains

• Temperature

• Amount of sunlight

• Presence of water miscible organic compounds

How is the iodine test used in plant physiology?

• To check for photosynthesis by detecting starch

• To measure plant growth

• To determine the water content in leaves

• To identify plant diseases

What is used as a control sample in the iodine test experiment?

• Cellulose sample

• Sucrose solution

• Distilled water

• Starch solution

Why does cellulose not show a positive iodine test?

• It has beta-1,4 glycosidic linkages forming linear chains

• It is insoluble in water

• It contains no glucose units

• It reacts with iodine to form a different color

What is the main difference between starch and cellulose in the context of the iodine test?

• Starch is a monosaccharide, cellulose is a polysaccharide

• Starch forms a helical structure, cellulose forms linear chains

• Starch is soluble in water, cellulose is not

• Starch is a protein, cellulose is a carbohydrate