Which of the following is a typical example of feedback inhibition ?

Options

A. Cyanide and cytochrome reaction
B. Sulpha drugs and folic acid synthesizer bacteria
C. Allosteric inhibition of hexokinase by glucose 6-phosphate
D. Reaction between succinic dehydrogenase and succinic acid

Answer

To solve the question "Which of the following is a typical example of feedback inhibition?", we will analyze the given options and determine which one represents feedback inhibition.

### Step-by-Step Solution:

1. **Understand Feedback Inhibition**:
- Feedback inhibition is a regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme involved in its synthesis. This prevents the overproduction of the product.

2. **Analyze the Options**:
- **Option A: Cyanide and cytochrome reaction**: This is an example of non-competitive inhibition, where cyanide inhibits the enzyme but does not involve feedback from a product.
- **Option B: Sulfur drugs and folic acid synthesizer bacteria**: This represents competitive inhibition, where the drug competes with the substrate for the active site of the enzyme.
- **Option C: Allosteric inhibition of hexokinase by glucose 6-phosphate**: Here, glucose 6-phosphate, the product of the reaction catalyzed by hexokinase, inhibits the enzyme by binding to a site other than the active site. This is a classic example of feedback inhibition.
- **Option D: Reaction between succinate dehydrogenase and succinic acid**: This is a standard enzymatic reaction and does not involve feedback inhibition.

3. **Identify the Correct Answer**:
- Based on the analysis, the correct answer is **Option C: Allosteric inhibition of hexokinase by glucose 6-phosphate**. This is a typical example of feedback inhibition.

### Final Answer:
The typical example of feedback inhibition is **allosteric inhibition of hexokinase by glucose 6-phosphate**.