I) `"Glucose"overset(a)rarr" glucose" - 6 -" phosphate"`
II) `"Glucose" - 6 - "phosphate"overset(b)rarr" fructose" - 6 - "phosphate"`
. a . and . b . represent two enzymes which catalyse the above reactions . The enzymes belong to classes

Options

A. a - Transferases , b - Isomerases
B. a - Isomerases , b - Hydrolases
C. a - Ligases , b - Hydrolases
D. a - Oxidoreductases , b - isomerases

Answer

To solve the question, we need to identify the classes of enzymes that catalyze the given reactions.

### Step-by-Step Solution:

1. **Identify the First Reaction:**
- The first reaction is the conversion of glucose to glucose-6-phosphate.
- This reaction is catalyzed by the enzyme **hexokinase**.

2. **Determine the Class of the First Enzyme:**
- Hexokinase is responsible for transferring a phosphate group to glucose.
- Enzymes that transfer functional groups (like phosphate groups) belong to the class of **transferases**.

3. **Identify the Second Reaction:**
- The second reaction is the conversion of glucose-6-phosphate to fructose-6-phosphate.
- This reaction is catalyzed by the enzyme **glucose-6-phosphate isomerase**.

4. **Determine the Class of the Second Enzyme:**
- The enzyme glucose-6-phosphate isomerase rearranges the structure of glucose-6-phosphate to fructose-6-phosphate.
- Enzymes that catalyze the rearrangement of atoms within a molecule belong to the class of **isomerases**.

5. **Final Conclusion:**
- Therefore, enzyme A (hexokinase) belongs to the class of **transferases** and enzyme B (glucose-6-phosphate isomerase) belongs to the class of **isomerases**.

### Final Answer:
- Enzyme A belongs to the class of **transferases**.
- Enzyme B belongs to the class of **isomerases**.

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