Which of the following statements is not incorrect ?

Options

A. Ovalbumin is a simple food reserve in egg - white
B. Blood proteins thrombin and fibrinogen are involved in blood clotting
C. Denaturation makes the proteins more active
D. Insulin maintains sugar level in the blood of a human body

Answer

To determine which of the following statements is not incorrect, we need to analyze each statement one by one:

1. **Statement 1**: "Ovalbumin is a simple food reserve in egg white."
- **Analysis**: Ovalbumin is indeed the main protein found in egg white and serves as a food reserve for the developing embryo. Therefore, this statement is correct.

2. **Statement 2**: "Blood proteins thrombin and fibrinogen are involved in blood clotting."
- **Analysis**: Thrombin and fibrinogen are both essential proteins in the blood clotting process. Thrombin converts fibrinogen into fibrin, which helps form blood clots. Hence, this statement is also correct.

3. **Statement 3**: "Denaturation makes the proteins more active."
- **Analysis**: Denaturation refers to the process where proteins lose their native structure due to the breaking of weak linkages (like hydrogen bonds). This process typically results in a loss of biological activity. Therefore, this statement is incorrect.

4. **Statement 4**: "Insulin maintains sugar level."
- **Analysis**: Insulin is a hormone produced by the pancreas that helps regulate blood sugar levels. When blood sugar levels rise, insulin facilitates the uptake of glucose by cells, thereby maintaining sugar levels in the blood. This statement is correct.

Now, summarizing the analysis:
- Statements 1, 2, and 4 are correct (not incorrect).
- Statement 3 is incorrect.

Thus, the statements that are not incorrect are 1, 2, and 4.

**Final Answer**: Statements 1, 2, and 4 are not incorrect.