Which of the following is a polysaccharide?

1. Analyze the question You are asked to pick the carbohydrate that is a polysaccharide, meaning a carbohydrate made of many (poly = many) sugar units joined together.

2. Explain the concept Carbohydrates fall into three groups:

• Monosaccharides are single sugar units, e.g. glucose, fructose, galactose.
• Disaccharides are two monosaccharides joined together, e.g. sucrose, maltose, lactose.
• Polysaccharides are many monosaccharides joined in long chains, e.g. starch, glycogen, cellulose.

3. Solution, option by option

• A. Glucose is a monosaccharide (C₆H₁₂O₆), a single sugar unit. ❌
• B. Sucrose is a disaccharide (glucose + fructose). ❌
• C. Maltose is a disaccharide (glucose + glucose). ❌
• D. Cellulose is a polysaccharide made of thousands of glucose units joined by β-1,4 glycosidic bonds. It forms plant cell walls. ✅

4. Answer The correct option is D. Cellulose.

5. Exam tip Remember: "-ose" ending = sugar, but check the size:

• Names of one unit are short and simple (glucose, fructose).
• Two units: sucrose, maltose, lactose. Think "SML" for the common disaccharides.
• Many units: starch, glycogen, cellulose. Think "plants store starch, animals store glycogen, plants build walls with cellulose."