Reducing sugars are simple carbohydrates having

Options

A. free aldose group
B. free ketose group
C. free aldose of free ketose group
D. no free aldose / ketose group

Answer

To solve the question regarding reducing sugars, we will analyze the characteristics of reducing sugars and their functional groups step by step.

### Step-by-Step Solution:

1. **Understanding Reducing Sugars**:
- Reducing sugars are a type of simple carbohydrate that can donate electrons to another molecule, thus reducing it. This property is due to the presence of certain functional groups.

2. **Identifying Functional Groups**:
- Reducing sugars typically contain a free aldehyde group (in aldoses) or a free ketone group (in ketoses). These groups are capable of participating in redox reactions.

3. **Types of Reducing Sugars**:
- Monosaccharides, such as glucose (an aldose) and fructose (a ketose), are examples of reducing sugars. They have either a free aldehyde or a free ketone group that allows them to act as reducing agents.

4. **Analyzing the Options**:
- A. Free aldose group: This option is partially correct but does not include ketoses.
- B. Free ketose group: This option is also partially correct but does not include aldoses.
- C. Free aldose or free ketose group: This option correctly encompasses both types of reducing sugars.
- D. No free aldose or free ketose group: This option is incorrect as reducing sugars must have one of these groups.

5. **Conclusion**:
- Based on the analysis, the correct answer is **C: free aldose or free ketose group**.