True statement for cellulose molecule is

Options

A. `beta-1-4` linkage, unbranched
B. `beta-1-4` linkage, branched
C. `alpha-1-4` linkage, branched
D. `beta-1-6` linkage, unbranched

Answer

To determine the true statement about cellulose, we can analyze the properties and structure of cellulose step by step.

### Step-by-Step Solution:

1. **Understanding Cellulose**:
- Cellulose is a polysaccharide that is the primary component of the cell wall in plants. It is also found in some fungi.
- It consists of long chains of glucose units.

**Hint**: Remember that cellulose is a structural polysaccharide primarily found in plant cell walls.

2. **Composition of Cellulose**:
- Cellulose is made up of approximately 6000 or more glucose units linked together.
- These glucose units are linked by specific types of glycosidic bonds.

**Hint**: Think about how glucose units are connected in polysaccharides and the significance of the type of linkage.

3. **Type of Linkage**:
- The linkage in cellulose is specifically a **beta-1,4 glycosidic linkage**. This means that the first carbon (C1) of one glucose molecule is linked to the fourth carbon (C4) of the next glucose molecule.
- This type of linkage is crucial as it determines the structure and properties of cellulose.

**Hint**: Focus on the specific type of glycosidic bond and its implications on the structure of cellulose.

4. **Structure of Cellulose**:
- Cellulose has an **unbranched structure**. Unlike starch and glycogen, which have branched structures, cellulose chains run parallel to each other and are held together by hydrogen bonds.
- This unbranched nature contributes to the rigidity and strength of plant cell walls.

**Hint**: Compare the structure of cellulose with that of starch and glycogen to understand the differences.

5. **Evaluating the Options**:
- Based on the above points, we can evaluate the given options:
- **Option 1**: Correctly states that cellulose has beta-1,4 linkages and is unbranched.
- **Option 2**: Incorrectly states that cellulose is branched.
- **Option 3**: Incorrectly mentions alpha-1,4 linkages, which are found in starch.
- **Option 4**: Incorrectly states beta-1,6 linkages, which are associated with glycogen.

**Hint**: Cross-check each option with the characteristics of cellulose to identify the true statement.

### Conclusion:
The true statement for cellulose is that it has **beta-1,4 linkages and is unbranched**. Therefore, the correct answer is **Option 1**.