Which of the following IS INCORRECT about glycogen ?

Options

A. It is a stored form of glucose in animals
B. In glycogen , right end is reducing and left end is non-reducing
C. It is a branched polymer of glucose
D. It is a good reducing agent

Answer

To determine which statement about glycogen is incorrect, we need to analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Glycogen**:
Glycogen is a polysaccharide that serves as a form of energy storage in animals. It is primarily composed of glucose units linked together.

2. **Evaluating the Statements**:
- **Statement A**: "It is a stored form of glucose in animals."
- This statement is **correct**. Glycogen is indeed the primary storage form of glucose in animals, mainly found in the liver and muscles.

- **Statement B**: "In glycogen, the right end is reducing and the left end is non-reducing."
- This statement is **correct**. In glycogen, the reducing end (which has a free aldehyde group) is at one end, while the other end is a non-reducing end (where the glucose unit is linked to another glucose unit).

- **Statement C**: "It is a branched polymer of glucose."
- This statement is also **correct**. Glycogen is a highly branched polymer of glucose, with branches occurring at intervals due to α(1→6) glycosidic bonds, while the main chain is formed by α(1→4) glycosidic bonds.

- **Statement D**: "It is a good reducing agent."
- This statement is **incorrect**. Glycogen, being a polysaccharide, is generally considered a non-reducing sugar. Reducing agents are typically monosaccharides or certain disaccharides that have free aldehyde or ketone groups.

3. **Conclusion**:
The statement that is incorrect about glycogen is **"It is a good reducing agent."** Therefore, the answer is **Option D**.