**Question:** Complex polysaccharides are converted to glucose and absorbed by the help of-

**Core Concept:** Complex polysaccharides are large carbohydrate molecules that cannot be absorbed directly by the small intestine without the help of specific enzymes and transporters. The conversion of complex polysaccharides to glucose allows for efficient absorption in the small intestine.

**Why the Correct Answer is Right:** Glucose is the primary energy source for the body, and its absorption is facilitated by specific transporters, such as SGLT1 (Sodium-Glucose Linked Transporter 1) and GLUT2 (Glucose Transporter Type 2). These transporters enable the passive transport of glucose across the intestinal cell membrane, ensuring efficient absorption.

**Why Each Wrong Option is Incorrect:**

A. **Incorrect:** Option A (Lactase) is not relevant as lactase is an enzyme responsible for breaking down lactose (a disaccharide) into glucose and galactose, not complex polysaccharides.

B. **Incorrect:** Option B (Maltase) is also not involved in the absorption of complex polysaccharides. Maltase is an enzyme responsible for breaking down maltose (a disaccharide) into glucose, not complex polysaccharides.

C. **Incorrect:** Option C (Sucrase) is an enzyme responsible for breaking down sucrose (a disaccharide) into glucose and fructose, not complex polysaccharides.

D. **Correct:** Option D (α-Amylase) is an enzyme responsible for breaking down complex polysaccharides (starch) into مالتوز (maltose) and other smaller oligosaccharides. Further digestion of these oligosaccharides by maltase, isomaltase, and sucrase leads to the conversion of complex polysaccharides into glucose, which is then absorbed by SGLT1 and GLUT2 transporters.

**Core Concept:** The correct answer (Option D) explains the sequential breakdown of complex polysaccharides into smaller molecules like maltose and then into glucose, which is transported across the intestinal cell membrane.

**Why Each Wrong Option is Incorrect:** Options A, B, and C are incorrect because they involve enzymes for disaccharide digestion, not polysaccharide digestion.

**Clinical Pearls:** The understanding of carbohydrate digestion and absorption is crucial for clinical practice, as impaired carbohydrate digestion can lead to malabsorption syndromes, such as lactose intolerance or malabsorption of lactose due to lack of lactase enzyme. Correct understanding of the process ensures proper diagnosis and management of such conditions.