Question

Describe the reactions of L-Fructose with the following test.

Tollen's test

Benedict's reagent

Seliwanoff's reagent

Yeast

Iodine

Answer 1

Structure of L-fructose

1. L-fructose contain ketone group, while Benedict's reagent test is only given by aldose sugars. So it will not give Benedict's reagent test .

2.L-fructose contain ketone group, while Benedict's reagent test is only given by aldose sugars. So it will not give Benedict's reagent test .

3. L-fructose contain ketone group, while Seliwanoff's reagent test is given by ketoses, reagent dehydrates ketohexoses to form 5-hydroxymethylfurfural having red colour.

4. It ferments L-fructose.

5. L-fructose is monosaccharide while Iodine test is given by only polysaccharides so it will not give this test.

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