Carrier ions like `Na^(+)` facilitate the absorption of substance like

Options

A. Fructose and some amino acids
B. Amino acids and glucose
C. Glucose and fatty acids
D. Fatty acids and glycerol

Answer

**Step-by-Step Text Solution:**

1. **Understanding Carrier Ions**: Carrier ions, such as sodium ions (Na+), play a crucial role in the absorption of nutrients in the small intestine.

2. **Role of the Small Intestine**: The primary function of the small intestine is to absorb simple substances that are derived from the digestion of complex food. These simple substances include carbohydrates, proteins, and fats.

3. **Identifying Simple Substances**: The simplest forms of carbohydrates are sugars, and the simplest forms of proteins are amino acids. In the small intestine, glucose (a simple sugar) and amino acids (the building blocks of proteins) are the key products that need to be absorbed.

4. **Co-Transport Mechanism**: Sodium ions facilitate the absorption of glucose and amino acids through a co-transport mechanism. This means that glucose and amino acids are transported together with sodium ions across the epithelial cells of the small intestine.

5. **Specific Co-Transporters**: There are specific co-transporters responsible for this process:
- **Na-glucose co-transporter**: This transporter helps in the absorption of glucose.
- **Na-amino acid co-transporter**: This transporter aids in the absorption of amino acids.

6. **Evaluating Options**: When considering the absorption facilitated by sodium ions, the correct substances are glucose and amino acids. Other options, such as fructose or fatty acids, do not utilize sodium ions in the same way for absorption.

7. **Conclusion**: Therefore, the correct answer to the question is that carrier ions like Na+ facilitate the absorption of substances like amino acids and glucose in the small intestine.