Just as hydrochloric acid is to pepsinogen, so is

Options

A. Hemoglobin oxygen
B. Enterokinase to typsinogen
C. Bile juice to fat
D. Glucagon to glycogen

Answer

To solve the question "Just as hydrochloric acid is to pepsinogen, so is ___?", we need to identify the relationship between hydrochloric acid and pepsinogen and find a similar relationship among the given options.

### Step-by-Step Solution:

1. **Understand the Relationship**:
- Hydrochloric acid (HCl) is involved in the conversion of pepsinogen (an inactive enzyme) into pepsin (its active form). This means HCl activates pepsinogen.

2. **Analyze the Options**:
- **Option A: Glucagon to Glycogen**:
- Glucagon is a hormone that raises blood glucose levels by converting glycogen (stored glucose) into glucose. This is not an activation process.
- **Option B: Bile Juice to Fat**:
- Bile juice helps in the emulsification of fats, which aids in digestion, but it does not convert an inactive form into an active form.
- **Option C: Enterokinase to Trypsinogen**:
- Enterokinase is an enzyme that activates trypsinogen (inactive form) into trypsin (active form). This is similar to how HCl activates pepsinogen.
- **Option D: Hemoglobin to Oxygen**:
- Hemoglobin carries oxygen but does not convert an inactive form into an active form. This is not a similar relationship.

3. **Identify the Correct Answer**:
- The relationship between hydrochloric acid and pepsinogen is that HCl activates pepsinogen. The only option that has a similar relationship is **Enterokinase to Trypsinogen**, where enterokinase activates trypsinogen.

4. **Conclusion**:
- Therefore, the answer is **Enterokinase to Trypsinogen**.

### Final Answer:
**Enterokinase to Trypsinogen**

---