In the complete absence of which the duoedenal digestion of chyme proteins not possible

Options

A. Enterokinase
B. Dil HCl
C. Gastrin
D. All the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which substance is essential for the duodenal digestion of chyme proteins. The duodenum is the first part of the small intestine where a significant amount of digestion occurs.

2. **Identifying Key Enzymes**: In the duodenum, proteins are primarily digested by enzymes. One of the critical enzymes involved in protein digestion is trypsin, which is activated from its inactive form, trypsinogen.

3. **Role of Enterokinase**: Enterokinase is an enzyme that is secreted by the intestinal mucosa. Its primary function is to convert trypsinogen (the inactive form) into trypsin (the active form). This conversion is crucial because trypsin is necessary for the digestion of proteins in the chyme.

4. **Consequences of Absence**: If enterokinase is absent, trypsinogen cannot be converted into trypsin. Without trypsin, the digestion of proteins in the duodenum cannot occur effectively, leading to incomplete digestion of chyme proteins.

5. **Eliminating Other Options**:
- Dilute HCl is found in the stomach and helps convert pepsinogen to pepsin, but it does not play a role in the duodenum.
- Gastrin is a hormone that stimulates gastric acid secretion and is also not involved in duodenal protein digestion.

6. **Conclusion**: Therefore, the complete absence of enterokinase would prevent the duodenal digestion of chyme proteins.

**Final Answer**: Enterokinase

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