Which of the following carbohydrates is not a sugar ?

Options

A. Glucose
B. Fructose
C. Lactose
D. Cellulose

Answer

To determine which carbohydrate is not a sugar, we need to understand the classification of carbohydrates. Carbohydrates can be classified into two main categories: simple carbohydrates (sugars) and complex carbohydrates (polysaccharides).

### Step-by-Step Solution:

1. **Define Carbohydrates**: Carbohydrates are organic compounds made up of carbon, hydrogen, and oxygen. They can be classified into simple carbohydrates (monosaccharides and disaccharides) and complex carbohydrates (polysaccharides).

2. **Identify Simple Carbohydrates (Sugars)**: Simple carbohydrates include monosaccharides like glucose and fructose, and disaccharides like sucrose and lactose. These are often referred to as sugars because they are sweet and soluble in water.

3. **Identify Complex Carbohydrates**: Complex carbohydrates, or polysaccharides, include starch, glycogen, and cellulose. These are made up of long chains of monosaccharide units and are usually not sweet.

4. **Analyze the Options**: If given a list of carbohydrates, we need to identify which one is a polysaccharide. For example, if the options include glucose, fructose, lactose, and cellulose, we can analyze them:
- Glucose: A monosaccharide (sugar).
- Fructose: A monosaccharide (sugar).
- Lactose: A disaccharide (sugar).
- Cellulose: A polysaccharide (not a sugar).

5. **Conclusion**: Among the given options, cellulose is the carbohydrate that is not a sugar. It is a complex carbohydrate made up of glucose units but does not exhibit the properties of sugars.

### Final Answer:
Cellulose is the carbohydrate that is not a sugar.

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