Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

9. Carbohydrates

Reducing Sugars

Biochemistry

9. Carbohydrates

Reducing Sugars

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Multiple Choice

Which reagent is commonly used to detect the presence of reducing (simple) sugars in a solution?

Iodine solution

Biuret reagent

Sudan III stain

Benedict's reagent

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Verified step by step guidance

Understand the concept of reducing sugars: Reducing sugars are carbohydrates that can donate electrons to other molecules, typically through their free aldehyde or ketone groups. This property allows them to participate in redox reactions.

Learn about Benedict's reagent: Benedict's reagent is a chemical solution containing copper(II) sulfate, sodium citrate, and sodium carbonate. It is specifically designed to detect reducing sugars by undergoing a color change during a redox reaction.

Understand the reaction mechanism: When reducing sugars are heated with Benedict's reagent, the free aldehyde or ketone groups reduce copper(II) ions (Cu²⁺) to copper(I) ions (Cu⁺). This reduction results in the formation of a precipitate of copper(I) oxide (Cu₂O), which changes the solution's color.

Compare Benedict's reagent with other reagents: Iodine solution is used to test for starch, Biuret reagent is used to detect proteins, and Sudan III stain is used to identify lipids. None of these reagents are suitable for detecting reducing sugars.

Conclude the application: Benedict's reagent is the correct choice for detecting reducing sugars because it specifically reacts with the free aldehyde or ketone groups in these sugars, producing a visible color change (e.g., green, yellow, orange, or red) depending on the concentration of reducing sugars.