Which of the following statement is not true abount glucose?

Options

A. It is an aldohexose
B. It contains five hydroxyl groups
C. It is a reducing sugar
D. It is an aldopentose

Answer

To determine which statement about glucose is not true, we need to analyze the properties and characteristics of glucose.

### Step-by-Step Solution:

1. **Identify the Chemical Structure of Glucose**:
- The chemical formula of glucose is \( C_6H_{12}O_6 \).
- Glucose is a simple sugar (monosaccharide) that contains six carbon atoms.

2. **Understanding the Classification of Glucose**:
- Glucose is classified as an **aldohexose** because it has an aldehyde group (-CHO) and contains six carbon atoms. This classification is important in understanding its chemical behavior.

3. **Count the Hydroxyl Groups**:
- In the structure of glucose, there are five hydroxyl groups (-OH) attached to the carbon atoms. This can be confirmed by drawing the structure of glucose.

4. **Determine if Glucose is a Reducing Sugar**:
- Glucose has a free aldehyde group, which allows it to act as a reducing sugar. Reducing sugars can donate electrons to other molecules, which is a key characteristic of glucose.

5. **Evaluate the Given Statements**:
- Now, we need to evaluate the statements provided in the question. The statements typically include:
- Glucose is an aldohexose.
- Glucose contains five hydroxyl groups.
- Glucose is a reducing sugar.
- Glucose is an aldo-pento (which is incorrect as it is an aldohexose).

6. **Identify the Incorrect Statement**:
- Among the options, the statement that glucose is an "aldo-pento" is not true because glucose is classified as an aldohexose, not an aldo-pento.

### Conclusion:
The statement that is not true about glucose is that it is an "aldo-pento".

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