Essential amino acids were discorvered by

Options

A. Evans and Burr
B. Hopkin
C. Beevers
D. Sutherland.

Answer

**Step-by-Step Solution:**

1. **Understanding Essential Amino Acids**:
- Essential amino acids are those that cannot be synthesized by the human body and must be obtained from the diet. There are 20 amino acids in total, out of which 9 are classified as essential.

2. **Identifying the Discoverer**:
- The question asks who discovered essential amino acids. The specific amino acid that is often highlighted in this context is tryptophan.

3. **Historical Context**:
- Tryptophan was isolated from a protein in the year 1901. The scientist responsible for this discovery is Sir Frederick Gowland Hopkins.

4. **Conclusion**:
- Based on the information, the correct answer to the question "Essential amino acids were discovered by" is Sir Frederick Gowland Hopkins.

**Final Answer**: The essential amino acids were discovered by Sir Frederick Gowland Hopkins.

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