Lecture On Protein Digestion & Absorption: Enzymes, Mechanisms & Clinical Insights | MBBS

Описание: In this high-yield lecture for the MBBS 2025-26 batch at Santiniketan Medical College, we break down how the body transforms complex proteins into absorbable amino acids.

This session is a "must-watch" for medical students (MBBS), NEET-PG/NEXT aspirants, and healthcare professionals, covering the entire pathway from the stomach to the portal circulation.

In this lecture, you will master:

Stomach Phase of Digestion: The critical role of HCl and Pepsinogen. Learn how the "Auto-catalytic" activation of Pepsin initiates the breakdown of large polypeptide chains [18:44].

Pancreatic Proteases: A detailed look at the inactive zymogens—Trypsinogen, Chymotrypsinogen, Procarboxypeptidase, and Proelastase—and their activation by Enterokinase [23:48].

Enzyme Specificity: Why we need multiple enzymes. Understanding where Trypsin (Arginine/Lysine) and Chymotrypsin (Aromatic amino acids) cut the peptide bonds [30:55].

Brush Border Digestion: The final step where Aminopeptidases and dipeptidases reduce molecules to single amino acids, dipeptides, and tripeptides [41:00].

Absorption Mechanisms: Exploring the Sodium-Amino Acid Symporter and the H+-Peptide Symporter (PEPT1) that drive nutrient uptake into the enterocytes [42:53].

Clinical Correlations: Differentiating between Malabsorption and Maldigestion, with insights into Celiac Disease and Pancreatic Insufficiency [03:49].

Key Timestamps for Quick Reference:

[01:31] - Review: Enzymes for Carbohydrate Digestion.

[03:49] - Maldigestion vs. Malabsorption: Where is the defect?

[07:27] - Fat vs. Carbohydrate Absorption: The role of Lacteals.

[09:50] - Introduction to Protein Digestion (Polypeptide Chains).

[15:22] - Role of Gastrin and Parietal cells (HCl).

[18:44] - Pepsin: Auto-catalytic activation and HCl requirements.

[23:48] - Pancreatic Enzymes: The "Zymogen" Cocktail.

[28:41] - Enterokinase: The master switch for Trypsin activation.

[30:55] - High-Yield: Enzyme Specificity for Amino Acids (Arginine, Lysine, etc.).

[41:00] - Aminopeptidases: Cleaving from the N-terminal.

[42:53] - Mechanism of Absorption: Na+/K+ ATPase and Symporters.

[44:48] - H+ dependent transport of Dipeptides and Tripeptides.

[47:07] - Intracellular Peptidases: The final breakdown inside the cell.

[51:58] - Summary: From Chicken pices to Portal Vein.


SANTINIKETAN MEDICAL COLLEGE & HOSPITAL
Real Classroom Demonstration/Lecture
On: PHYSIOLOGY by Prof. (Dr.) Subhasis Mukherjee
(MBBS Batch: 2025-26)
Conducted on: 29-12-25