Study the following reactions given below catalysed by enzymes A, B, C and D.
। .Maltose `underset(to)(A)` Glucose + Glucose II. Starch `underset(to)(B)` Maltose + Isomaltose III. Nucleic acids `underset(to)(C)` Nucleotides
IV. Lactose `underset(to)(D)`Glucose + Galactose Choose the option which includes enzymes present in succus entericus

Options

A. A and B
B. A and C
C. C and D
D. A and D

Answer

To solve the question regarding the enzymes present in succus entericus, we will analyze each reaction and identify the enzymes involved:

### Step-by-Step Solution:

1. **Identify the Reactions and Enzymes**:
- **Reaction I**: Maltose `underset(to)(A)` Glucose + Glucose
- **Reaction II**: Starch `underset(to)(B)` Maltose + Isomaltose
- **Reaction III**: Nucleic acids `underset(to)(C)` Nucleotides
- **Reaction IV**: Lactose `underset(to)(D)` Glucose + Galactose

2. **Analyze Each Reaction**:
- **Reaction I**: The enzyme A converts maltose into glucose. The enzyme responsible for this reaction is **maltase**, which is present in succus entericus (small intestine).
- **Reaction II**: The enzyme B converts starch into maltose and isomaltose. This reaction is primarily catalyzed by **amylase**, which is not a part of succus entericus but is secreted by the pancreas. Therefore, this enzyme is not included.
- **Reaction III**: The enzyme C converts nucleic acids into nucleotides. This reaction is also catalyzed by enzymes from pancreatic juice, not by succus entericus. Thus, this enzyme is not included.
- **Reaction IV**: The enzyme D converts lactose into glucose and galactose. The enzyme responsible for this reaction is **lactase**, which is present in succus entericus.

3. **Conclusion**:
- The enzymes present in succus entericus from the reactions analyzed are:
- Enzyme A (maltase) from Reaction I
- Enzyme D (lactase) from Reaction IV

4. **Final Answer**:
- The correct option that includes enzymes present in succus entericus is **Option A and D**.