Glucose in the lumen of gut is absorbed:

Options

A. Mainly by active absorption & some by passive absorption
B. Mainly by passive absorption & some by active absorption .
C. Only by active absorption
D. Only by active absorption absorption

Answer

To solve the question about how glucose in the lumen of the gut is absorbed, we can break down the process into clear steps:

### Step-by-Step Solution:

1. **Understanding Glucose Absorption**: Glucose absorption occurs in the small intestine, where glucose from the lumen needs to cross the intestinal epithelium to enter the bloodstream.

2. **Transport Mechanisms**: There are two primary mechanisms for glucose transport across the intestinal epithelium:
- **Active Transport**: This process requires energy (ATP) and is mediated by specific transport proteins. The main transporter involved in glucose absorption is SGLT1 (Sodium-Glucose Linked Transporter 1). This transporter uses the sodium gradient to co-transport glucose against its concentration gradient.
- **Facilitated Diffusion**: This process does not require energy and allows glucose to move down its concentration gradient through specific transporter proteins, such as GLUT2. This is known as passive transport.

3. **Proportions of Transport Mechanisms**: In the gut, approximately 90% of glucose absorption occurs via active transport (SGLT1), while about 10% occurs through facilitated diffusion (GLUT2).

4. **Conclusion**: Based on the mechanisms and their proportions, we can conclude that glucose in the lumen of the gut is absorbed mainly by active transport, with some contribution from passive transport.

5. **Final Answer**: The correct statement regarding glucose absorption in the gut is that it is mainly absorbed by active transport and some by passive transport.