Enzyme that does not follow `K_(m)` value is

Options

A. Exoenzyme
B. Allosteric enzyme
C. Isoenzyme
D. Pepsin.

Answer

To solve the question "Enzyme that does not follow `K_m` value is," we will follow these steps:

### Step 1: Understand the `K_m` Value
- The `K_m` value, known as Michaelis constant, is a crucial parameter in enzyme kinetics. It represents the substrate concentration at which the reaction rate is half of its maximum velocity (V_max).
- A low `K_m` value indicates high affinity between the enzyme and its substrate, while a high `K_m` value indicates low affinity.

**Hint for Step 1:** Remember that `K_m` reflects the affinity of the enzyme for its substrate.

### Step 2: Identify Types of Enzymes
- The question provides several options: exoenzyme, allosteric enzyme, isoenzyme, and peptidine.
- We need to analyze each type of enzyme to determine which one does not follow the `K_m` value.

**Hint for Step 2:** Consider the characteristics of each enzyme type listed in the options.

### Step 3: Analyze Allosteric Enzymes
- Allosteric enzymes do not follow Michaelis-Menten kinetics. Instead, they exhibit a sigmoid (S-shaped) saturation curve when plotted against substrate concentration.
- This behavior is due to the cooperative binding of substrates, which is not described by a simple `K_m` value.

**Hint for Step 3:** Focus on the behavior of allosteric enzymes in relation to substrate binding.

### Step 4: Conclusion
- Based on the analysis, the enzyme that does not follow the `K_m` value is the allosteric enzyme. This is because allosteric enzymes do not exhibit a simple hyperbolic relationship between substrate concentration and reaction rate, which is what `K_m` describes.

**Final Answer:** The enzyme that does not follow `K_m` value is **allosteric enzyme**.