Which one of the following enzymes can hydrolyze both ester and amide bonds?
(1) Methionine racemase
(2) Thrombin
(3) Chymotrypsin
(4) Peroxidase
📘 Problem Statement
Which one of the following enzymes can hydrolyze both ester and amide bonds?
Options:
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Methionine racemase
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Thrombin
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Chymotrypsin
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Peroxidase
🔬 Understanding the Concept: Enzyme Functions
Enzymes are biological molecules that catalyze specific reactions by lowering the activation energy. In this case, we are focused on enzymes that can break down ester and amide bonds. These types of bonds are crucial in biochemical processes:
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Ester bonds are commonly found in fats and lipids.
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Amide bonds are typically seen in proteins, linking amino acids in peptide chains.
For an enzyme to hydrolyze both ester and amide bonds, it must possess the right active site configuration and catalytic mechanism to interact with both types of bonds.
🧠 Detailed Breakdown of Each Enzyme:
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Methionine Racemase:
This enzyme is responsible for converting L-methionine into D-methionine, an important process in amino acid metabolism. However, it does not hydrolyze ester or amide bonds, making it not the correct answer. -
Thrombin:
Thrombin is a serine protease involved in blood clotting. It primarily cleaves peptide bonds (amide bonds) in proteins, but it does not hydrolyze ester bonds. Thus, thrombin is not the correct answer. -
Chymotrypsin:
Chymotrypsin is a serine protease that can hydrolyze peptide bonds in proteins (amide bonds). Additionally, it is known to break ester bonds, making it the only enzyme in this list capable of hydrolyzing both types of bonds. Chymotrypsin plays a key role in protein digestion and has a broad substrate specificity that includes ester hydrolysis. This is the correct answer. -
Peroxidase:
Peroxidases are enzymes involved in the breakdown of hydrogen peroxide and other peroxides. They do not hydrolyze ester or amide bonds. Therefore, peroxidase is not the correct answer.
✅ Correct Answer: (3) Chymotrypsin
Chymotrypsin is a versatile enzyme that can hydrolyze both ester bonds (as in ester-containing substrates) and amide bonds (in protein substrates). This ability makes it particularly important in both protein digestion and enzyme catalysis.
📝 Summary Table
| Enzyme | Function | Can Hydrolyze Ester and Amide Bonds? |
|---|---|---|
| Methionine Racemase | Converts L-methionine to D-methionine | No |
| Thrombin | Cleaves peptide bonds in proteins (blood clotting) | No |
| Chymotrypsin | Hydrolyzes peptide bonds (proteins) and ester bonds (lipids) | Yes |
| Peroxidase | Reduces hydrogen peroxide to water or oxygen | No |
💡 Why This Question is Important
Understanding enzyme specificity and function is critical in:
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Biochemistry: Grasping how enzymes catalyze reactions in metabolic pathways.
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Medicine: Identifying enzyme roles in health and disease, such as digestive enzymes like chymotrypsin.
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Biotechnology: Applications in protein engineering, drug design, and enzymatic processes.
✅ Key Takeaways
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Chymotrypsin is the enzyme that can hydrolyze both ester and amide bonds.
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It is a serine protease, involved in protein digestion and capable of breaking both peptide and ester bonds.
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Enzyme specificity is crucial for understanding biological processes in both living organisms and biotechnological applications.
