Enterokinase stimulates which of the following `:-`

Options

A. Pepsinogen
B. trypsin
C. Pepsin
D. Trypsinogen

Answer

**Step-by-Step Solution:**

1. **Understanding Enterokinase**: Enterokinase is an enzyme secreted by the Brunner's glands in the small intestine. Its primary role is to activate other enzymes that are secreted in inactive forms.

2. **Identifying the Options**: The question provides four options:
- A) Pepsinogen
- B) Trypsin
- C) Pepsin
- D) Trypsinogen

3. **Analyzing Pepsinogen**: Pepsinogen is an inactive enzyme that is converted to pepsin in the stomach by hydrochloric acid (HCl). Since enterokinase functions in the small intestine, it does not stimulate pepsinogen.

4. **Analyzing Trypsin**: Trypsin is the active form of the enzyme that is involved in protein digestion. However, enterokinase does not stimulate trypsin; instead, it activates trypsinogen to trypsin.

5. **Analyzing Pepsin**: Pepsin is the active form of pepsinogen and is not related to the function of enterokinase. Thus, it is not the correct answer.

6. **Analyzing Trypsinogen**: Trypsinogen is an inactive precursor of trypsin that is secreted by the pancreas into the small intestine. Enterokinase specifically activates trypsinogen into trypsin.

7. **Conclusion**: The correct answer to the question "Enterokinase stimulates which of the following?" is **D) Trypsinogen**.