fatty substance are emulsified by

Options

A. Lipase
B. Bilirubin and biliverdin
C. Hcl
D. Sodium salts of glycocholic and traurocholic

Answer

To answer the question "Fatty substances are emulsified by," we will analyze the options provided and identify the correct one step by step.

### Step-by-Step Solution:

1. **Understanding Emulsification**:
- Emulsification is the process of mixing two immiscible liquids, such as oil and water, to form a stable mixture. In the context of digestion, it refers to the breakdown of fats into smaller droplets, which increases the surface area for enzymes to act upon.

2. **Identifying the Role of Bile Salts**:
- Bile salts, produced by the liver and stored in the gallbladder, play a crucial role in the emulsification of fats. They are composed of sodium salts of bile acids, such as glycocholic acid and taurocholic acid.

3. **Evaluating the Options**:
- **Lipase**: This enzyme is responsible for the digestion of fats by breaking them down into fatty acids and glycerol. However, it does not emulsify fats. Therefore, this option is incorrect.
- **Bilirubin and Biliverdin**: These are pigments produced from the breakdown of hemoglobin in the liver. They do not play a role in fat emulsification. Thus, this option is incorrect.
- **HCl (Hydrochloric Acid)**: This acid is present in gastric juice and aids in digestion but does not emulsify fats. Therefore, this option is also incorrect.
- **Sodium salts of glycocholic and taurocholic acids**: These are the components of bile salts that are specifically involved in the emulsification of fats. This option is correct.

4. **Conclusion**:
- The correct answer to the question "Fatty substances are emulsified by" is **sodium salts of glycocholic and taurocholic acids**.

### Final Answer:
Fatty substances are emulsified by sodium salts of glycocholic and taurocholic acids.